- Linux-stable-mirror - lists.linaro.org

[PATCH v5.15] vhost-scsi: protect vq->log_used with vq->mutex

by Xinyu Zheng

From: Dongli Zhang <dongli.zhang(a)oracle.com> [ Upstream commit f591cf9fce724e5075cc67488c43c6e39e8cbe27 ] The vhost-scsi completion path may access vq->log_base when vq->log_used is already set to false. vhost-thread QEMU-thread vhost_scsi_complete_cmd_work() -> vhost_add_used() -> vhost_add_used_n() if (unlikely(vq->log_used)) QEMU disables vq->log_used via VHOST_SET_VRING_ADDR. mutex_lock(&vq->mutex); vq->log_used = false now! mutex_unlock(&vq->mutex); QEMU gfree(vq->log_base) log_used() -> log_write(vq->log_base) Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be reclaimed via gfree(). As a result, this causes invalid memory writes to QEMU userspace. The control queue path has the same issue. Cc: stable(a)vger.kernel.org#5.15.x Cc: gregkh(a)linuxfoundation.org Signed-off-by: Dongli Zhang <dongli.zhang(a)oracle.com> Acked-by: Jason Wang <jasowang(a)redhat.com> Reviewed-by: Mike Christie <michael.christie(a)oracle.com> Message-Id: <20250403063028.16045-2-dongli.zhang(a)oracle.com> Signed-off-by: Michael S. Tsirkin <mst(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> [ Conflicts in drivers/vhost/scsi.c bacause vhost_scsi_complete_cmd_work() has been refactored. ] Signed-off-by: Xinyu Zheng <zhengxinyu6(a)huawei.com> --- drivers/vhost/scsi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index f9930887fdd2..2c19fa02141d 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -563,8 +563,10 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter); if (likely(ret == sizeof(v_rsp))) { struct vhost_scsi_virtqueue *q; - vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0); q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq); + mutex_lock(&q->vq.mutex); + vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0); + mutex_unlock(&q->vq.mutex); vq = q - vs->vqs; __set_bit(vq, signal); } else @@ -1166,8 +1168,11 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work) else resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED; + mutex_lock(&tmf->svq->vq.mutex); vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs, tmf->vq_desc, &tmf->resp_iov, resp_code); + mutex_unlock(&tmf->svq->vq.mutex); + vhost_scsi_release_tmf_res(tmf); } -- 2.34.1

2 months

1
0
0 0

[PATCH v5.10 v2] vhost-scsi: protect vq->log_used with vq->mutex

by Xinyu Zheng

From: Dongli Zhang <dongli.zhang(a)oracle.com> [ Upstream commit f591cf9fce724e5075cc67488c43c6e39e8cbe27 ] The vhost-scsi completion path may access vq->log_base when vq->log_used is already set to false. vhost-thread QEMU-thread vhost_scsi_complete_cmd_work() -> vhost_add_used() -> vhost_add_used_n() if (unlikely(vq->log_used)) QEMU disables vq->log_used via VHOST_SET_VRING_ADDR. mutex_lock(&vq->mutex); vq->log_used = false now! mutex_unlock(&vq->mutex); QEMU gfree(vq->log_base) log_used() -> log_write(vq->log_base) Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be reclaimed via gfree(). As a result, this causes invalid memory writes to QEMU userspace. The control queue path has the same issue. Cc: stable(a)vger.kernel.org#5.10.x Cc: gregkh(a)linuxfoundation.org Signed-off-by: Dongli Zhang <dongli.zhang(a)oracle.com> Acked-by: Jason Wang <jasowang(a)redhat.com> Reviewed-by: Mike Christie <michael.christie(a)oracle.com> Message-Id: <20250403063028.16045-2-dongli.zhang(a)oracle.com> Signed-off-by: Michael S. Tsirkin <mst(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> [ Conflicts in drivers/vhost/scsi.c bacause vhost_scsi_complete_cmd_work() has been refactored. ] Signed-off-by: Xinyu Zheng <zhengxinyu6(a)huawei.com> --- V1 -> V2: Remove unnecessary CVE tag drivers/vhost/scsi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index a23a65e7d828..fcde3752b4f1 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -579,8 +579,10 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter); if (likely(ret == sizeof(v_rsp))) { struct vhost_scsi_virtqueue *q; - vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0); q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq); + mutex_lock(&q->vq.mutex); + vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0); + mutex_unlock(&q->vq.mutex); vq = q - vs->vqs; __set_bit(vq, signal); } else @@ -1193,8 +1195,11 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work) else resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED; + mutex_lock(&tmf->svq->vq.mutex); vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs, tmf->vq_desc, &tmf->resp_iov, resp_code); + mutex_unlock(&tmf->svq->vq.mutex); + vhost_scsi_release_tmf_res(tmf); } -- 2.34.1

2 months

1
0
0 0

Host panic in bpf verifier when loading bpf prog in 5.10 stable kernel

by Aaron Lu

Hello, Wei reported when loading his bpf prog in 5.10.200 kernel, host would panic, this didn't happen in 5.10.135 kernel. Test on latest v5.10.238 still has this panic. [ 26.531718] BUG: kernel NULL pointer dereference, address: 0000000000000168 [ 26.538093] #PF: supervisor read access in kernel mode [ 26.542727] #PF: error_code(0x0000) - not-present page [ 26.548093] PGD 10f3e9067 P4D 10f332067 PUD 10f0c5067 PMD 0 [ 26.553211] Oops: 0000 [#1] SMP NOPTI [ 26.556531] CPU: 2 PID: 541 Comm: main Not tainted 5.10.238-00267-g01e7e36b8606 #63 [ 26.563816] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 26.572357] RIP: 0010:__mark_chain_precision+0x24b/0x4d0 [ 26.576572] Code: 51 01 be 20 00 00 00 4c 89 ef 48 63 d2 e8 bd df 31 00 89 c1 83 f8 1f 7f 29 48 63 d1 48 89 d0 48 c1 e0 04 48 29 d0 48 8d 04 c3 <83> 38 01 75 c3 0f b6 74 24 06 80 78 74 00 c6 40 74 01 44 0f 44 f6 [ 26.589100] RSP: 0018:ffa0000000ff7b60 EFLAGS: 00010216 [ 26.592612] RAX: 0000000000000168 RBX: 0000000000000000 RCX: 0000000000000003 [ 26.597416] RDX: 0000000000000003 RSI: 0000000000000020 RDI: ffa0000000ff7b78 [ 26.601362] RBP: 0000000000000003 R08: ffa0000000ff7b70 R09: 0000000000000004 [ 26.604261] R10: 0000000000000007 R11: ffa0000000425000 R12: ff11000102ee2000 [ 26.607202] R13: ffa0000000ff7b78 R14: 0000000000000000 R15: ff1100010ee37140 [ 26.610327] FS: 00000000007a0630(0000) GS:ff1100081c400000(0000) knlGS:0000000000000000 [ 26.613678] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 26.616105] CR2: 0000000000000168 CR3: 0000000115e72002 CR4: 0000000000371ee0 [ 26.619059] Call Trace: [ 26.620118] adjust_reg_min_max_vals+0x133/0x340 [ 26.622048] ? krealloc+0x63/0xe0 [ 26.623435] do_check+0x38c/0xa80 [ 26.624859] do_check_common+0x15b/0x280 [ 26.626496] bpf_check+0xbe1/0xd30 [ 26.627939] ? srso_alias_return_thunk+0x5/0x7f [ 26.629796] ? trace_hardirqs_on+0x1a/0xd0 [ 26.631503] ? srso_alias_return_thunk+0x5/0x7f [ 26.633402] bpf_prog_load+0x422/0x8a0 [ 26.634987] ? srso_alias_return_thunk+0x5/0x7f [ 26.636864] ? __handle_mm_fault+0x3cb/0x6d0 [ 26.638658] ? srso_alias_return_thunk+0x5/0x7f [ 26.640543] ? lock_release+0xe3/0x110 [ 26.642114] __do_sys_bpf+0x485/0xdf0 [ 26.643624] do_syscall_64+0x33/0x40 [ 26.645110] entry_SYSCALL_64_after_hwframe+0x67/0xd1 [ 26.647190] RIP: 0033:0x409a6e [ 26.648470] Code: 24 28 44 8b 44 24 2c e9 70 ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 [ 26.656154] RSP: 002b:000000c00199edc0 EFLAGS: 00000212 ORIG_RAX: 0000000000000141 [ 26.659451] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000409a6e [ 26.662375] RDX: 0000000000000098 RSI: 000000c00199f290 RDI: 0000000000000005 [ 26.665267] RBP: 000000c00199ee00 R08: 0000000000000000 R09: 0000000000000000 [ 26.668204] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 [ 26.671125] R13: 0000000000000080 R14: 000000c000002380 R15: 8080808080808080 [ 26.674085] Modules linked in: [ 26.675363] CR2: 0000000000000168 [ 26.676772] ---[ end trace 3fc192ee4dabbf12 ]--- [ 26.678667] RIP: 0010:__mark_chain_precision+0x24b/0x4d0 [ 26.680926] Code: 51 01 be 20 00 00 00 4c 89 ef 48 63 d2 e8 bd df 31 00 89 c1 83 f8 1f 7f 29 48 63 d1 48 89 d0 48 c1 e0 04 48 29 d0 48 8d 04 c3 <83> 38 01 75 c3 0f b6 74 24 06 80 78 74 00 c6 40 74 01 44 0f 44 f6 [ 26.688665] RSP: 0018:ffa0000000ff7b60 EFLAGS: 00010216 [ 26.690828] RAX: 0000000000000168 RBX: 0000000000000000 RCX: 0000000000000003 [ 26.693777] RDX: 0000000000000003 RSI: 0000000000000020 RDI: ffa0000000ff7b78 [ 26.696680] RBP: 0000000000000003 R08: ffa0000000ff7b70 R09: 0000000000000004 [ 26.699651] R10: 0000000000000007 R11: ffa0000000425000 R12: ff11000102ee2000 [ 26.702561] R13: ffa0000000ff7b78 R14: 0000000000000000 R15: ff1100010ee37140 [ 26.705522] FS: 00000000007a0630(0000) GS:ff1100081c400000(0000) knlGS:0000000000000000 [ 26.708806] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 26.711179] CR2: 0000000000000168 CR3: 0000000115e72002 CR4: 0000000000371ee0 [ 26.714143] Kernel panic - not syncing: Fatal exception [ 26.716893] Kernel Offset: disabled [ 26.718911] Rebooting in 5 seconds.. I did a bisect in linux-5.10.y branch and found the fbc is commit 2474ec58b96d("bpf: allow precision tracking for programs with subprogs"). I noticed there is a commit in Linus master branch that has a fix tag for this bisected commit: commit 81335f90e8a8("bpf: unconditionally reset backtrack_state masks on global func exit"), I tried to apply it in this 5.10.y branch but since the bases are quite different, clean apply is not possible, I end up with the following diff: diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 40ac67a04ab75..71da33fb96552 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2118,11 +2118,9 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int frame, int r bitmap_from_u64(mask, reg_mask); for_each_set_bit(i, mask, 32) { reg = &st->frame[0]->regs[i]; - if (reg->type != SCALAR_VALUE) { - reg_mask &= ~(1u << i); - continue; - } - reg->precise = true; + reg_mask &= ~(1u << i); + if (reg->type == SCALAR_VALUE) + reg->precise = true; } return 0; } But it didn't make any difference. Here are the reproduce steps: 1 clone this repo https://github.com/bytedance/vArmor-ebpf and switch to panic-analysis branch; 2 make build A binary named main should be built. I used golang compiler downloaded here: https://go.dev/dl/go1.24.3.linux-amd64.tar.gz but other golang compiler may also work. Run main as root and it will panic the host(kernel needs CONFIG_BPF_LSM). Full dmesg and config are attached, feel free to let me know if you need any additional info, thanks. P.S. linux-5.15.y has the same situation.

2 months

3
11
0 0

[PATCH 1/1] iommu/sva: Invalidate KVA range on kernel TLB flush

by Lu Baolu

The vmalloc() and vfree() functions manage virtually contiguous, but not necessarily physically contiguous, kernel memory regions. When vfree() unmaps such a region, it tears down the associated kernel page table entries and frees the physical pages. In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU hardware shares and walks the CPU's page tables. Architectures like x86 share static kernel address mappings across all user page tables, allowing the IOMMU to access the kernel portion of these tables. Modern IOMMUs often cache page table entries to optimize walk performance, even for intermediate page table levels. If kernel page table mappings are changed (e.g., by vfree()), but the IOMMU's internal caches retain stale entries, Use-After-Free (UAF) vulnerability condition arises. If these freed page table pages are reallocated for a different purpose, potentially by an attacker, the IOMMU could misinterpret the new data as valid page table entries. This allows the IOMMU to walk into attacker-controlled memory, leading to arbitrary physical memory DMA access or privilege escalation. To mitigate this, introduce a new iommu interface to flush IOMMU caches and fence pending page table walks when kernel page mappings are updated. This interface should be invoked from architecture-specific code that manages combined user and kernel page tables. Fixes: 26b25a2b98e4 ("iommu: Bind process address spaces to devices") Cc: stable(a)vger.kernel.org Co-developed-by: Jason Gunthorpe <jgg(a)nvidia.com> Signed-off-by: Jason Gunthorpe <jgg(a)nvidia.com> Signed-off-by: Lu Baolu <baolu.lu(a)linux.intel.com> --- arch/x86/mm/tlb.c | 2 ++ drivers/iommu/iommu-sva.c | 32 +++++++++++++++++++++++++++++++- include/linux/iommu.h | 4 ++++ 3 files changed, 37 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 39f80111e6f1..a41499dfdc3f 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -12,6 +12,7 @@ #include <linux/task_work.h> #include <linux/mmu_notifier.h> #include <linux/mmu_context.h> +#include <linux/iommu.h> #include <asm/tlbflush.h> #include <asm/mmu_context.h> @@ -1540,6 +1541,7 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end) kernel_tlb_flush_range(info); put_flush_tlb_info(); + iommu_sva_invalidate_kva_range(start, end); } /* diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 1a51cfd82808..154384eab8a3 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -10,6 +10,8 @@ #include "iommu-priv.h" static DEFINE_MUTEX(iommu_sva_lock); +static DEFINE_STATIC_KEY_FALSE(iommu_sva_present); +static LIST_HEAD(iommu_sva_mms); static struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, struct mm_struct *mm); @@ -42,6 +44,7 @@ static struct iommu_mm_data *iommu_alloc_mm_data(struct mm_struct *mm, struct de return ERR_PTR(-ENOSPC); } iommu_mm->pasid = pasid; + iommu_mm->mm = mm; INIT_LIST_HEAD(&iommu_mm->sva_domains); /* * Make sure the write to mm->iommu_mm is not reordered in front of @@ -132,8 +135,13 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm if (ret) goto out_free_domain; domain->users = 1; - list_add(&domain->next, &mm->iommu_mm->sva_domains); + if (list_empty(&iommu_mm->sva_domains)) { + if (list_empty(&iommu_sva_mms)) + static_branch_enable(&iommu_sva_present); + list_add(&iommu_mm->mm_list_elm, &iommu_sva_mms); + } + list_add(&domain->next, &iommu_mm->sva_domains); out: refcount_set(&handle->users, 1); mutex_unlock(&iommu_sva_lock); @@ -175,6 +183,13 @@ void iommu_sva_unbind_device(struct iommu_sva *handle) list_del(&domain->next); iommu_domain_free(domain); } + + if (list_empty(&iommu_mm->sva_domains)) { + list_del(&iommu_mm->mm_list_elm); + if (list_empty(&iommu_sva_mms)) + static_branch_disable(&iommu_sva_present); + } + mutex_unlock(&iommu_sva_lock); kfree(handle); } @@ -312,3 +327,18 @@ static struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, return domain; } + +void iommu_sva_invalidate_kva_range(unsigned long start, unsigned long end) +{ + struct iommu_mm_data *iommu_mm; + + might_sleep(); + + if (!static_branch_unlikely(&iommu_sva_present)) + return; + + guard(mutex)(&iommu_sva_lock); + list_for_each_entry(iommu_mm, &iommu_sva_mms, mm_list_elm) + mmu_notifier_arch_invalidate_secondary_tlbs(iommu_mm->mm, start, end); +} +EXPORT_SYMBOL_GPL(iommu_sva_invalidate_kva_range); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 156732807994..31330c12b8ee 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1090,7 +1090,9 @@ struct iommu_sva { struct iommu_mm_data { u32 pasid; + struct mm_struct *mm; struct list_head sva_domains; + struct list_head mm_list_elm; }; int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode); @@ -1571,6 +1573,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm); void iommu_sva_unbind_device(struct iommu_sva *handle); u32 iommu_sva_get_pasid(struct iommu_sva *handle); +void iommu_sva_invalidate_kva_range(unsigned long start, unsigned long end); #else static inline struct iommu_sva * iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) @@ -1595,6 +1598,7 @@ static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm) } static inline void mm_pasid_drop(struct mm_struct *mm) {} +static inline void iommu_sva_invalidate_kva_range(unsigned long start, unsigned long end) {} #endif /* CONFIG_IOMMU_SVA */ #ifdef CONFIG_IOMMU_IOPF -- 2.43.0

2 months

11
22
0 0

[PATCH net-next v2 1/2] net: ipv4: fix incorrect MTU in broadcast routes

by Oscar Maes

Currently, __mkroute_output overrules the MTU value configured for broadcast routes. This buggy behaviour can be reproduced with: ip link set dev eth1 mtu 9000 ip route del broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 ip route add broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 mtu 1500 The maximum packet size should be 1500, but it is actually 8000: ping -b 192.168.0.255 -s 8000 Fix __mkroute_output to allow MTU values to be configured for for broadcast routes (to support a mixed-MTU local-area-network). Signed-off-by: Oscar Maes <oscmaes92(a)gmail.com> --- net/ipv4/route.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 64ba377cd..f639a2ae8 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2588,7 +2588,6 @@ static struct rtable *__mkroute_output(const struct fib_result *res, do_cache = true; if (type == RTN_BROADCAST) { flags |= RTCF_BROADCAST | RTCF_LOCAL; - fi = NULL; } else if (type == RTN_MULTICAST) { flags |= RTCF_MULTICAST | RTCF_LOCAL; if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, -- 2.39.5

2 months

3
3
0 0

[PATCH AUTOSEL 5.4] rxrpc: Fix oops due to non-existence of prealloc backlog struct

by Sasha Levin

From: David Howells <dhowells(a)redhat.com> [ Upstream commit 880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4 ] If an AF_RXRPC service socket is opened and bound, but calls are preallocated, then rxrpc_alloc_incoming_call() will oops because the rxrpc_backlog struct doesn't get allocated until the first preallocation is made. Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no backlog struct. This will cause the incoming call to be aborted. Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque(a)tencent.com> Suggested-by: Junvyyang, Tencent Zhuque Lab <zhuque(a)tencent.com> Signed-off-by: David Howells <dhowells(a)redhat.com> cc: LePremierHomme <kwqcheii(a)proton.me> cc: Marc Dionne <marc.dionne(a)auristor.com> cc: Willy Tarreau <w(a)1wt.eu> cc: Simon Horman <horms(a)kernel.org> cc: linux-afs(a)lists.infradead.org Link: https://patch.msgid.link/20250708211506.2699012-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: **YES** This commit should be backported to stable kernel trees for the following reasons: 1. **Fixes a Critical Kernel Oops**: The commit addresses a NULL pointer dereference that causes a kernel crash when `rx->backlog` is NULL. At line 257 of the original code, `smp_load_acquire(&b->call_backlog_head)` would dereference a NULL pointer if no preallocation was done. 2. **Minimal and Safe Fix**: The fix is a simple defensive check: ```c + if (!b) + return NULL; ``` This is placed immediately after obtaining the backlog pointer and before any usage. The fix has zero risk of regression - if `b` is NULL, the code would have crashed anyway. 3. **Clear Reproducible Scenario**: The bug occurs in a specific but realistic scenario - when an AF_RXRPC service socket is opened and bound but no calls are preallocated (meaning `rxrpc_service_prealloc()` was never called to allocate the backlog structure). 4. **Follows Stable Kernel Rules**: This fix meets all criteria for stable backporting: - Fixes a real bug that users can hit - Small and contained change (2 lines) - Obviously correct with no side effects - Already tested and merged upstream 5. **Similar to Previously Backported Fixes**: Looking at Similar Commit #2 which was marked YES, it also fixed an oops in the rxrpc preallocation/backlog system with minimal changes. The commit prevents a kernel crash with a trivial NULL check, making it an ideal candidate for stable backporting. net/rxrpc/call_accept.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 55fb3744552de..99f05057e4c90 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -281,6 +281,9 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx, unsigned short call_tail, conn_tail, peer_tail; unsigned short call_count, conn_count; + if (!b) + return NULL; + /* #calls >= #conns >= #peers must hold true. */ call_head = smp_load_acquire(&b->call_backlog_head); call_tail = b->call_backlog_tail; -- 2.39.5

2 months

1
0
0 0

[PATCH AUTOSEL 5.10] rxrpc: Fix oops due to non-existence of prealloc backlog struct

by Sasha Levin

From: David Howells <dhowells(a)redhat.com> [ Upstream commit 880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4 ] If an AF_RXRPC service socket is opened and bound, but calls are preallocated, then rxrpc_alloc_incoming_call() will oops because the rxrpc_backlog struct doesn't get allocated until the first preallocation is made. Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no backlog struct. This will cause the incoming call to be aborted. Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque(a)tencent.com> Suggested-by: Junvyyang, Tencent Zhuque Lab <zhuque(a)tencent.com> Signed-off-by: David Howells <dhowells(a)redhat.com> cc: LePremierHomme <kwqcheii(a)proton.me> cc: Marc Dionne <marc.dionne(a)auristor.com> cc: Willy Tarreau <w(a)1wt.eu> cc: Simon Horman <horms(a)kernel.org> cc: linux-afs(a)lists.infradead.org Link: https://patch.msgid.link/20250708211506.2699012-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: **YES** This commit should be backported to stable kernel trees for the following reasons: 1. **Fixes a Critical Kernel Oops**: The commit addresses a NULL pointer dereference that causes a kernel crash when `rx->backlog` is NULL. At line 257 of the original code, `smp_load_acquire(&b->call_backlog_head)` would dereference a NULL pointer if no preallocation was done. 2. **Minimal and Safe Fix**: The fix is a simple defensive check: ```c + if (!b) + return NULL; ``` This is placed immediately after obtaining the backlog pointer and before any usage. The fix has zero risk of regression - if `b` is NULL, the code would have crashed anyway. 3. **Clear Reproducible Scenario**: The bug occurs in a specific but realistic scenario - when an AF_RXRPC service socket is opened and bound but no calls are preallocated (meaning `rxrpc_service_prealloc()` was never called to allocate the backlog structure). 4. **Follows Stable Kernel Rules**: This fix meets all criteria for stable backporting: - Fixes a real bug that users can hit - Small and contained change (2 lines) - Obviously correct with no side effects - Already tested and merged upstream 5. **Similar to Previously Backported Fixes**: Looking at Similar Commit #2 which was marked YES, it also fixed an oops in the rxrpc preallocation/backlog system with minimal changes. The commit prevents a kernel crash with a trivial NULL check, making it an ideal candidate for stable backporting. net/rxrpc/call_accept.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 2a14d69b171f3..b96af42a1b041 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -271,6 +271,9 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx, unsigned short call_tail, conn_tail, peer_tail; unsigned short call_count, conn_count; + if (!b) + return NULL; + /* #calls >= #conns >= #peers must hold true. */ call_head = smp_load_acquire(&b->call_backlog_head); call_tail = b->call_backlog_tail; -- 2.39.5

2 months

1
0
0 0

[PATCH AUTOSEL 5.15 1/3] rxrpc: Fix oops due to non-existence of prealloc backlog struct

by Sasha Levin

From: David Howells <dhowells(a)redhat.com> [ Upstream commit 880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4 ] If an AF_RXRPC service socket is opened and bound, but calls are preallocated, then rxrpc_alloc_incoming_call() will oops because the rxrpc_backlog struct doesn't get allocated until the first preallocation is made. Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no backlog struct. This will cause the incoming call to be aborted. Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque(a)tencent.com> Suggested-by: Junvyyang, Tencent Zhuque Lab <zhuque(a)tencent.com> Signed-off-by: David Howells <dhowells(a)redhat.com> cc: LePremierHomme <kwqcheii(a)proton.me> cc: Marc Dionne <marc.dionne(a)auristor.com> cc: Willy Tarreau <w(a)1wt.eu> cc: Simon Horman <horms(a)kernel.org> cc: linux-afs(a)lists.infradead.org Link: https://patch.msgid.link/20250708211506.2699012-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: **YES** This commit should be backported to stable kernel trees for the following reasons: 1. **Fixes a Critical Kernel Oops**: The commit addresses a NULL pointer dereference that causes a kernel crash when `rx->backlog` is NULL. At line 257 of the original code, `smp_load_acquire(&b->call_backlog_head)` would dereference a NULL pointer if no preallocation was done. 2. **Minimal and Safe Fix**: The fix is a simple defensive check: ```c + if (!b) + return NULL; ``` This is placed immediately after obtaining the backlog pointer and before any usage. The fix has zero risk of regression - if `b` is NULL, the code would have crashed anyway. 3. **Clear Reproducible Scenario**: The bug occurs in a specific but realistic scenario - when an AF_RXRPC service socket is opened and bound but no calls are preallocated (meaning `rxrpc_service_prealloc()` was never called to allocate the backlog structure). 4. **Follows Stable Kernel Rules**: This fix meets all criteria for stable backporting: - Fixes a real bug that users can hit - Small and contained change (2 lines) - Obviously correct with no side effects - Already tested and merged upstream 5. **Similar to Previously Backported Fixes**: Looking at Similar Commit #2 which was marked YES, it also fixed an oops in the rxrpc preallocation/backlog system with minimal changes. The commit prevents a kernel crash with a trivial NULL check, making it an ideal candidate for stable backporting. net/rxrpc/call_accept.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 99e10eea37321..658b592e58e05 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -270,6 +270,9 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx, unsigned short call_tail, conn_tail, peer_tail; unsigned short call_count, conn_count; + if (!b) + return NULL; + /* #calls >= #conns >= #peers must hold true. */ call_head = smp_load_acquire(&b->call_backlog_head); call_tail = b->call_backlog_tail; -- 2.39.5

2 months

1
2
0 0

[PATCH AUTOSEL 6.1 1/4] net/sched: sch_qfq: Fix null-deref in agg_dequeue

by Sasha Levin

From: Xiang Mei <xmei5(a)asu.edu> [ Upstream commit dd831ac8221e691e9e918585b1003c7071df0379 ] To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c) when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return value before using it, similar to the existing approach in sch_hfsc.c. To avoid code duplication, the following changes are made: 1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static inline function. 2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to include/net/pkt_sched.h so that sch_qfq can reuse it. 3. Applied qdisc_peek_len in agg_dequeue to avoid crashing. Signed-off-by: Xiang Mei <xmei5(a)asu.edu> Reviewed-by: Cong Wang <xiyou.wangcong(a)gmail.com> Link: https://patch.msgid.link/20250705212143.3982664-1-xmei5@asu.edu Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: Based on my analysis of the commit and related code, here is my assessment: **YES** - This commit should be backported to stable kernel trees. Here's my extensive explanation: ## Reason for Backporting 1. **Real Bug Fix**: This commit fixes a NULL pointer dereference bug in `agg_dequeue()` function in `net/sched/sch_qfq.c`. The bug occurs when `cl->qdisc->ops->peek(cl->qdisc)` returns NULL, but the code at line 992 (before the fix) directly uses this potentially NULL value in `qdisc_pkt_len()` without checking: ```c else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) ``` 2. **Crash Prevention**: This is not a theoretical issue - it causes an actual kernel crash (NULL pointer dereference) that can affect system stability. This meets the stable kernel criteria of fixing "a real bug that bothers people" including "an oops, a hang, data corruption." 3. **Similar Patterns in Other Schedulers**: The commit shows that this pattern of NULL checking after peek operations is already implemented in other packet schedulers: - `sch_hfsc.c` already has the `qdisc_peek_len()` function with NULL checking - `sch_drr.c` checks for NULL after peek operations (lines 385-387) - The similar commit #1 shows DRR had a similar issue fixed 4. **Minimal and Contained Fix**: The fix is: - Small in size (well under 100 lines) - Obviously correct - it adds proper NULL checking - Moves existing code to be reusable - Makes the code more consistent across schedulers 5. **Precedent from Similar Commits**: Looking at the historical commits: - Similar commit #2 (sch_codel NULL check) was backported (Status: YES) - Similar commit #3 (multiple schedulers NULL handling) was backported (Status: YES) - Both dealt with NULL pointer handling in packet scheduler dequeue paths 6. **Code Consolidation**: The fix properly consolidates the NULL checking logic: - Converts `qdisc_warn_nonwc` from a regular function to static inline (reducing overhead) - Moves `qdisc_peek_len` from sch_hfsc.c to the common header so it can be reused - Uses the same pattern across multiple schedulers for consistency 7. **Tested Pattern**: The `qdisc_peek_len()` function being moved has been in use in sch_hfsc.c, proving it's a tested and working solution. 8. **Security Consideration**: While not explicitly a security vulnerability, NULL pointer dereferences can potentially be exploited for denial of service attacks, making this fix important for system stability. The commit follows all the stable kernel rules: it fixes a real bug (NULL pointer dereference), is obviously correct (adds NULL check), is small and contained, and improves consistency across the codebase. The pattern of backporting similar NULL check fixes in packet schedulers (as seen in similar commits #2 and #3) supports backporting this fix as well. include/net/pkt_sched.h | 25 ++++++++++++++++++++++++- net/sched/sch_api.c | 10 ---------- net/sched/sch_hfsc.c | 16 ---------------- net/sched/sch_qfq.c | 2 +- 4 files changed, 25 insertions(+), 28 deletions(-) diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index f99a513b40a92..76f9fb651faff 100644 --- a/include/net/pkt_sched.h +++ b/include/net/pkt_sched.h @@ -113,7 +113,6 @@ struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct netlink_ext_ack *extack); void qdisc_put_rtab(struct qdisc_rate_table *tab); void qdisc_put_stab(struct qdisc_size_table *tab); -void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc); bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, struct net_device *dev, struct netdev_queue *txq, spinlock_t *root_lock, bool validate); @@ -247,4 +246,28 @@ static inline bool tc_qdisc_stats_dump(struct Qdisc *sch, return true; } +static inline void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) +{ + if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { + pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", + txt, qdisc->ops->id, qdisc->handle >> 16); + qdisc->flags |= TCQ_F_WARN_NONWC; + } +} + +static inline unsigned int qdisc_peek_len(struct Qdisc *sch) +{ + struct sk_buff *skb; + unsigned int len; + + skb = sch->ops->peek(sch); + if (unlikely(skb == NULL)) { + qdisc_warn_nonwc("qdisc_peek_len", sch); + return 0; + } + len = qdisc_pkt_len(skb); + + return len; +} + #endif diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 7c5df62421bbd..6a2d258b01daa 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -593,16 +593,6 @@ void __qdisc_calculate_pkt_len(struct sk_buff *skb, qdisc_skb_cb(skb)->pkt_len = pkt_len; } -void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) -{ - if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { - pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", - txt, qdisc->ops->id, qdisc->handle >> 16); - qdisc->flags |= TCQ_F_WARN_NONWC; - } -} -EXPORT_SYMBOL(qdisc_warn_nonwc); - static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) { struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 61b91de8065f0..302413e0aceff 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -836,22 +836,6 @@ update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time) } } -static unsigned int -qdisc_peek_len(struct Qdisc *sch) -{ - struct sk_buff *skb; - unsigned int len; - - skb = sch->ops->peek(sch); - if (unlikely(skb == NULL)) { - qdisc_warn_nonwc("qdisc_peek_len", sch); - return 0; - } - len = qdisc_pkt_len(skb); - - return len; -} - static void hfsc_adjust_levels(struct hfsc_class *cl) { diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index 6462468bf77c7..cde6c7026ab1d 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -991,7 +991,7 @@ static struct sk_buff *agg_dequeue(struct qfq_aggregate *agg, if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */ list_del_init(&cl->alist); - else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) { + else if (cl->deficit < qdisc_peek_len(cl->qdisc)) { cl->deficit += agg->lmax; list_move_tail(&cl->alist, &agg->active); } -- 2.39.5

2 months

1
3
0 0

[PATCH AUTOSEL 6.6 1/6] net/sched: sch_qfq: Fix null-deref in agg_dequeue

by Sasha Levin

From: Xiang Mei <xmei5(a)asu.edu> [ Upstream commit dd831ac8221e691e9e918585b1003c7071df0379 ] To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c) when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return value before using it, similar to the existing approach in sch_hfsc.c. To avoid code duplication, the following changes are made: 1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static inline function. 2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to include/net/pkt_sched.h so that sch_qfq can reuse it. 3. Applied qdisc_peek_len in agg_dequeue to avoid crashing. Signed-off-by: Xiang Mei <xmei5(a)asu.edu> Reviewed-by: Cong Wang <xiyou.wangcong(a)gmail.com> Link: https://patch.msgid.link/20250705212143.3982664-1-xmei5@asu.edu Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: Based on my analysis of the commit and related code, here is my assessment: **YES** - This commit should be backported to stable kernel trees. Here's my extensive explanation: ## Reason for Backporting 1. **Real Bug Fix**: This commit fixes a NULL pointer dereference bug in `agg_dequeue()` function in `net/sched/sch_qfq.c`. The bug occurs when `cl->qdisc->ops->peek(cl->qdisc)` returns NULL, but the code at line 992 (before the fix) directly uses this potentially NULL value in `qdisc_pkt_len()` without checking: ```c else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) ``` 2. **Crash Prevention**: This is not a theoretical issue - it causes an actual kernel crash (NULL pointer dereference) that can affect system stability. This meets the stable kernel criteria of fixing "a real bug that bothers people" including "an oops, a hang, data corruption." 3. **Similar Patterns in Other Schedulers**: The commit shows that this pattern of NULL checking after peek operations is already implemented in other packet schedulers: - `sch_hfsc.c` already has the `qdisc_peek_len()` function with NULL checking - `sch_drr.c` checks for NULL after peek operations (lines 385-387) - The similar commit #1 shows DRR had a similar issue fixed 4. **Minimal and Contained Fix**: The fix is: - Small in size (well under 100 lines) - Obviously correct - it adds proper NULL checking - Moves existing code to be reusable - Makes the code more consistent across schedulers 5. **Precedent from Similar Commits**: Looking at the historical commits: - Similar commit #2 (sch_codel NULL check) was backported (Status: YES) - Similar commit #3 (multiple schedulers NULL handling) was backported (Status: YES) - Both dealt with NULL pointer handling in packet scheduler dequeue paths 6. **Code Consolidation**: The fix properly consolidates the NULL checking logic: - Converts `qdisc_warn_nonwc` from a regular function to static inline (reducing overhead) - Moves `qdisc_peek_len` from sch_hfsc.c to the common header so it can be reused - Uses the same pattern across multiple schedulers for consistency 7. **Tested Pattern**: The `qdisc_peek_len()` function being moved has been in use in sch_hfsc.c, proving it's a tested and working solution. 8. **Security Consideration**: While not explicitly a security vulnerability, NULL pointer dereferences can potentially be exploited for denial of service attacks, making this fix important for system stability. The commit follows all the stable kernel rules: it fixes a real bug (NULL pointer dereference), is obviously correct (adds NULL check), is small and contained, and improves consistency across the codebase. The pattern of backporting similar NULL check fixes in packet schedulers (as seen in similar commits #2 and #3) supports backporting this fix as well. include/net/pkt_sched.h | 25 ++++++++++++++++++++++++- net/sched/sch_api.c | 10 ---------- net/sched/sch_hfsc.c | 16 ---------------- net/sched/sch_qfq.c | 2 +- 4 files changed, 25 insertions(+), 28 deletions(-) diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index 15960564e0c36..4d72d24b1f33e 100644 --- a/include/net/pkt_sched.h +++ b/include/net/pkt_sched.h @@ -112,7 +112,6 @@ struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct netlink_ext_ack *extack); void qdisc_put_rtab(struct qdisc_rate_table *tab); void qdisc_put_stab(struct qdisc_size_table *tab); -void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc); bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, struct net_device *dev, struct netdev_queue *txq, spinlock_t *root_lock, bool validate); @@ -306,4 +305,28 @@ static inline bool tc_qdisc_stats_dump(struct Qdisc *sch, return true; } +static inline void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) +{ + if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { + pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", + txt, qdisc->ops->id, qdisc->handle >> 16); + qdisc->flags |= TCQ_F_WARN_NONWC; + } +} + +static inline unsigned int qdisc_peek_len(struct Qdisc *sch) +{ + struct sk_buff *skb; + unsigned int len; + + skb = sch->ops->peek(sch); + if (unlikely(skb == NULL)) { + qdisc_warn_nonwc("qdisc_peek_len", sch); + return 0; + } + len = qdisc_pkt_len(skb); + + return len; +} + #endif diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 282423106f15d..ae63b3199b1d1 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -594,16 +594,6 @@ void __qdisc_calculate_pkt_len(struct sk_buff *skb, qdisc_skb_cb(skb)->pkt_len = pkt_len; } -void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) -{ - if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { - pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", - txt, qdisc->ops->id, qdisc->handle >> 16); - qdisc->flags |= TCQ_F_WARN_NONWC; - } -} -EXPORT_SYMBOL(qdisc_warn_nonwc); - static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) { struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index afcb83d469ff6..751b1e2c35b3f 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -835,22 +835,6 @@ update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time) } } -static unsigned int -qdisc_peek_len(struct Qdisc *sch) -{ - struct sk_buff *skb; - unsigned int len; - - skb = sch->ops->peek(sch); - if (unlikely(skb == NULL)) { - qdisc_warn_nonwc("qdisc_peek_len", sch); - return 0; - } - len = qdisc_pkt_len(skb); - - return len; -} - static void hfsc_adjust_levels(struct hfsc_class *cl) { diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index 5e557b960bde3..e0cefa21ce21c 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -992,7 +992,7 @@ static struct sk_buff *agg_dequeue(struct qfq_aggregate *agg, if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */ list_del_init(&cl->alist); - else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) { + else if (cl->deficit < qdisc_peek_len(cl->qdisc)) { cl->deficit += agg->lmax; list_move_tail(&cl->alist, &agg->active); } -- 2.39.5

2 months

1
5
0 0

[PATCH AUTOSEL 6.12 01/12] wifi: mac80211: always initialize sdata::key_list

by Sasha Levin

From: Miri Korenblit <miriam.rachel.korenblit(a)intel.com> [ Upstream commit d7a54d02db41f72f0581a3c77c75b0993ed3f6e2 ] This is currently not initialized for a virtual monitor, leading to a NULL pointer dereference when - for example - iterating over all the keys of all the vifs. Reviewed-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Miri Korenblit <miriam.rachel.korenblit(a)intel.com> Link: https://patch.msgid.link/20250709233400.8dcefe578497.I4c90a00ae3256520e0631… Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: Based on my analysis of the commit and the code changes, here is my assessment: **YES** This commit should be backported to stable kernel trees for the following reasons: 1. **Critical NULL Pointer Dereference Fix**: The commit fixes a NULL pointer dereference that occurs when iterating over the key_list of virtual monitor interfaces. This is a crash-inducing bug that affects system stability. 2. **Clear Bug with Simple Fix**: The issue is straightforward - the `key_list` was not initialized for virtual monitor interfaces created via `ieee80211_add_virtual_monitor()`. The fix is minimal and contained - it simply moves the `INIT_LIST_HEAD(&sdata->key_list)` initialization from `ieee80211_if_add()` into `ieee80211_sdata_init()`, ensuring all sdata structures have their key_list properly initialized. 3. **Real-World Impact**: The bug can be triggered when any code iterates over all interfaces and their keys. Looking at the code, functions like `ieee80211_iter_keys()` and `ieee80211_iter_keys_rcu()` iterate through all interfaces when called without a specific vif parameter: ```c list_for_each_entry(sdata, &local->interfaces, list) list_for_each_entry_safe(key, tmp, &sdata->key_list, list) ``` This would cause a NULL pointer dereference when it encounters a virtual monitor interface. 4. **Minimal Risk**: The change is extremely low risk - it only adds initialization of a list head that should have been initialized all along. There are no architectural changes or feature additions. 5. **Follows Stable Rules**: This perfectly fits the stable kernel criteria: - Fixes a real bug (NULL pointer dereference/crash) - Small and contained change (2 lines moved) - Obviously correct fix - No new features or behaviors introduced The commit is similar in nature to commit #5 in the reference list which was marked as suitable for backporting - both fix NULL pointer dereferences in the wifi/mac80211 subsystem with minimal, targeted changes. net/mac80211/iface.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 209d6ffa8e426..adfdc14bd91ac 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1121,6 +1121,8 @@ static void ieee80211_sdata_init(struct ieee80211_local *local, { sdata->local = local; + INIT_LIST_HEAD(&sdata->key_list); + /* * Initialize the default link, so we can use link_id 0 for non-MLD, * and that continues to work for non-MLD-aware drivers that use just @@ -2162,8 +2164,6 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name, ieee80211_init_frag_cache(&sdata->frags); - INIT_LIST_HEAD(&sdata->key_list); - wiphy_delayed_work_init(&sdata->dec_tailroom_needed_wk, ieee80211_delayed_tailroom_dec); -- 2.39.5

2 months

1
11
0 0

[PATCH AUTOSEL 6.15 01/15] wifi: mac80211: always initialize sdata::key_list

by Sasha Levin

From: Miri Korenblit <miriam.rachel.korenblit(a)intel.com> [ Upstream commit d7a54d02db41f72f0581a3c77c75b0993ed3f6e2 ] This is currently not initialized for a virtual monitor, leading to a NULL pointer dereference when - for example - iterating over all the keys of all the vifs. Reviewed-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Miri Korenblit <miriam.rachel.korenblit(a)intel.com> Link: https://patch.msgid.link/20250709233400.8dcefe578497.I4c90a00ae3256520e0631… Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: Based on my analysis of the commit and the code changes, here is my assessment: **YES** This commit should be backported to stable kernel trees for the following reasons: 1. **Critical NULL Pointer Dereference Fix**: The commit fixes a NULL pointer dereference that occurs when iterating over the key_list of virtual monitor interfaces. This is a crash-inducing bug that affects system stability. 2. **Clear Bug with Simple Fix**: The issue is straightforward - the `key_list` was not initialized for virtual monitor interfaces created via `ieee80211_add_virtual_monitor()`. The fix is minimal and contained - it simply moves the `INIT_LIST_HEAD(&sdata->key_list)` initialization from `ieee80211_if_add()` into `ieee80211_sdata_init()`, ensuring all sdata structures have their key_list properly initialized. 3. **Real-World Impact**: The bug can be triggered when any code iterates over all interfaces and their keys. Looking at the code, functions like `ieee80211_iter_keys()` and `ieee80211_iter_keys_rcu()` iterate through all interfaces when called without a specific vif parameter: ```c list_for_each_entry(sdata, &local->interfaces, list) list_for_each_entry_safe(key, tmp, &sdata->key_list, list) ``` This would cause a NULL pointer dereference when it encounters a virtual monitor interface. 4. **Minimal Risk**: The change is extremely low risk - it only adds initialization of a list head that should have been initialized all along. There are no architectural changes or feature additions. 5. **Follows Stable Rules**: This perfectly fits the stable kernel criteria: - Fixes a real bug (NULL pointer dereference/crash) - Small and contained change (2 lines moved) - Obviously correct fix - No new features or behaviors introduced The commit is similar in nature to commit #5 in the reference list which was marked as suitable for backporting - both fix NULL pointer dereferences in the wifi/mac80211 subsystem with minimal, targeted changes. net/mac80211/iface.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 7d93e5aa595b2..0485a78eda366 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1117,6 +1117,8 @@ static void ieee80211_sdata_init(struct ieee80211_local *local, { sdata->local = local; + INIT_LIST_HEAD(&sdata->key_list); + /* * Initialize the default link, so we can use link_id 0 for non-MLD, * and that continues to work for non-MLD-aware drivers that use just @@ -2177,8 +2179,6 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name, ieee80211_init_frag_cache(&sdata->frags); - INIT_LIST_HEAD(&sdata->key_list); - wiphy_delayed_work_init(&sdata->dec_tailroom_needed_wk, ieee80211_delayed_tailroom_dec); -- 2.39.5

2 months

1
14
0 0

[PATCH] HID: multitouch: fix slab out-of-bounds access in mt_report_fixup()

by Qasim Ijaz

A malicious HID device can trigger a slab out-of-bounds during mt_report_fixup() by passing in report descriptor smaller than 607 bytes. mt_report_fixup() attempts to patch byte offset 607 of the descriptor with 0x25 by first checking if byte offset 607 is 0x15 however it lacks bounds checks to verify if the descriptor is big enough before conducting this check. Fix this vulnerability by ensuring the descriptor size is greater than or equal to 608 before accessing it. Below is the KASAN splat after the out of bounds access happens: [ 13.671954] ================================================================== [ 13.672667] BUG: KASAN: slab-out-of-bounds in mt_report_fixup+0x103/0x110 [ 13.673297] Read of size 1 at addr ffff888103df39df by task kworker/0:1/10 [ 13.673297] [ 13.673297] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.15.0-00005-gec5d573d83f4-dirty #3 [ 13.673297] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/04 [ 13.673297] Call Trace: [ 13.673297] <TASK> [ 13.673297] dump_stack_lvl+0x5f/0x80 [ 13.673297] print_report+0xd1/0x660 [ 13.673297] kasan_report+0xe5/0x120 [ 13.673297] __asan_report_load1_noabort+0x18/0x20 [ 13.673297] mt_report_fixup+0x103/0x110 [ 13.673297] hid_open_report+0x1ef/0x810 [ 13.673297] mt_probe+0x422/0x960 [ 13.673297] hid_device_probe+0x2e2/0x6f0 [ 13.673297] really_probe+0x1c6/0x6b0 [ 13.673297] __driver_probe_device+0x24f/0x310 [ 13.673297] driver_probe_device+0x4e/0x220 [ 13.673297] __device_attach_driver+0x169/0x320 [ 13.673297] bus_for_each_drv+0x11d/0x1b0 [ 13.673297] __device_attach+0x1b8/0x3e0 [ 13.673297] device_initial_probe+0x12/0x20 [ 13.673297] bus_probe_device+0x13d/0x180 [ 13.673297] device_add+0xe3a/0x1670 [ 13.673297] hid_add_device+0x31d/0xa40 [...] Fixes: c8000deb6836 ("HID: multitouch: Add support for GT7868Q") Cc: stable(a)vger.kernel.org Signed-off-by: Qasim Ijaz <qasdev00(a)gmail.com> --- drivers/hid/hid-multitouch.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 7ac8e16e6158..af4abe3ba410 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1461,18 +1461,25 @@ static const __u8 *mt_report_fixup(struct hid_device *hdev, __u8 *rdesc, if (hdev->vendor == I2C_VENDOR_ID_GOODIX && (hdev->product == I2C_DEVICE_ID_GOODIX_01E8 || hdev->product == I2C_DEVICE_ID_GOODIX_01E9)) { - if (rdesc[607] == 0x15) { - rdesc[607] = 0x25; - dev_info( - &hdev->dev, - "GT7868Q report descriptor fixup is applied.\n"); + if (*size >= 608) { + if (rdesc[607] == 0x15) { + rdesc[607] = 0x25; + dev_info( + &hdev->dev, + "GT7868Q report descriptor fixup is applied.\n"); + } else { + dev_info( + &hdev->dev, + "The byte is not expected for fixing the report descriptor. \ + It's possible that the touchpad firmware is not suitable for applying the fix. \ + got: %x\n", + rdesc[607]); + } } else { dev_info( &hdev->dev, - "The byte is not expected for fixing the report descriptor. \ -It's possible that the touchpad firmware is not suitable for applying the fix. \ -got: %x\n", - rdesc[607]); + "GT7868Q fixup: report descriptor only %u bytes, skipping\n", + *size); } } -- 2.39.5

2 months

1
0
0 0

[PATCH] ARM: Fix allowing linker DCE with binutils < 2.36

by Nathan Chancellor

Commit e7607f7d6d81 ("ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE") accidentally broke the binutils version restriction that was added in commit 0d437918fb64 ("ARM: 9414/1: Fix build issue with LD_DEAD_CODE_DATA_ELIMINATION"), reintroducing the segmentation fault addressed by that workaround. Restore the binutils version dependency by using CONFIG_LD_CAN_USE_KEEP_IN_OVERLAY as an additional condition to ensure that CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION is only enabled with binutils >= 2.36 and ld.lld >= 21.0.0. Cc: stable(a)vger.kernel.org Fixes: e7607f7d6d81 ("ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE") Reported-by: Rob Landley <rob(a)landley.net> Closes: https://lore.kernel.org/6739da7d-e555-407a-b5cb-e5681da71056@landley.net/ Tested-by: Rob Landley <rob(a)landley.net> Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- arch/arm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 3072731fe09c..962451e54fdd 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -121,7 +121,7 @@ config ARM select HAVE_KERNEL_XZ select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M select HAVE_KRETPROBES if HAVE_KPROBES - select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_CAN_USE_KEEP_IN_OVERLAY) + select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD) && LD_CAN_USE_KEEP_IN_OVERLAY select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_OPTPROBES if !THUMB2_KERNEL --- base-commit: d7b8f8e20813f0179d8ef519541a3527e7661d3a change-id: 20250707-arm-fix-dce-older-binutils-87a5a4b829d9 Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

2 months

1
1
0 0

[stable-6.1] x86: Fix X86_FEATURE_VERW_CLEAR definition

by Jack Wang

This is a mistake during backport. VERW_CLEAR is on bit 5, not bit 10. Fixes: d12145e8454f ("x86/bugs: Add a Transient Scheduler Attacks mitigation") Cc: Borislav Petkov (AMD) <bp(a)alien8.de> Signed-off-by: Jack Wang <jinpu.wang(a)ionos.com> --- arch/x86/include/asm/cpufeatures.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 1c71f947b426..6f6ea3b9a95e 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -429,8 +429,8 @@ #define X86_FEATURE_V_TSC_AUX (19*32+ 9) /* "" Virtual TSC_AUX */ #define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */ +#define X86_FEATURE_VERW_CLEAR (20*32+ 5) /* "" The memory form of VERW mitigates TSA */ #define X86_FEATURE_AUTOIBRS (20*32+ 8) /* "" Automatic IBRS */ -#define X86_FEATURE_VERW_CLEAR (20*32+ 10) /* "" The memory form of VERW mitigates TSA */ #define X86_FEATURE_SBPB (20*32+27) /* "" Selective Branch Prediction Barrier */ #define X86_FEATURE_IBPB_BRTYPE (20*32+28) /* "" MSR_PRED_CMD[IBPB] flushes all branch type predictions */ #define X86_FEATURE_SRSO_NO (20*32+29) /* "" CPU is not affected by SRSO */ -- 2.43.0

2 months

2
1
0 0

[stable-5.15] x86: Fix X86_FEATURE_VERW_CLEAR definition

by Jack Wang

This is a mistake during backport. VERW_CLEAR is on bit 5, not bit 10. Fixes: f2b75f1368af ("x86/bugs: Add a Transient Scheduler Attacks mitigation") Cc: Borislav Petkov (AMD) <bp(a)alien8.de> Signed-off-by: Jack Wang <jinpu.wang(a)ionos.com> --- arch/x86/include/asm/cpufeatures.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 63b84540cfb3..b8d945d8d34f 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -418,8 +418,8 @@ #define X86_FEATURE_SEV_ES (19*32+ 3) /* AMD Secure Encrypted Virtualization - Encrypted State */ #define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */ +#define X86_FEATURE_VERW_CLEAR (20*32+ 5) /* "" The memory form of VERW mitigates TSA */ #define X86_FEATURE_AUTOIBRS (20*32+ 8) /* "" Automatic IBRS */ -#define X86_FEATURE_VERW_CLEAR (20*32+ 10) /* "" The memory form of VERW mitigates TSA */ #define X86_FEATURE_SBPB (20*32+27) /* "" Selective Branch Prediction Barrier */ #define X86_FEATURE_IBPB_BRTYPE (20*32+28) /* "" MSR_PRED_CMD[IBPB] flushes all branch type predictions */ #define X86_FEATURE_SRSO_NO (20*32+29) /* "" CPU is not affected by SRSO */ -- 2.43.0

2 months

1
0
0 0

TSA mitigation doesn't work on 6.6.y

by Thomas Voegtle

Hello, with kernel v6.16-rc5-121-gbc9ff192a6c9 I see this: cat /sys/devices/system/cpu/vulnerabilities/tsa Mitigation: Clear CPU buffers dmesg | grep micro [ 1.479203] microcode: Current revision: 0x0a20102e [ 1.479206] microcode: Updated early from: 0x0a201016 So, this works. but same machine with 6.6.97: dmesg | grep micro [ 0.451496] Transient Scheduler Attacks: Vulnerable: Clear CPU buffers attempted, no microcode [ 1.077149] microcode: Current revision: 0x0a20102e [ 1.077152] microcode: Updated early from: 0x0a201016 so: cat /sys/devices/system/cpu/vulnerabilities/tsa Vulnerable: Clear CPU buffers attempted, no microcode but it is switched on: zcat /proc/config.gz | grep TSA CONFIG_MITIGATION_TSA=y And other stuff which need microcode works: cat /sys/devices/system/cpu/vulnerabilities/spec_rstack_overflow Mitigation: Safe RET without microcode you wwould see: Vulnerable: Safe RET, no microcode 6.12.37 broken too 6.15.6 works v6.16-rc5-121-gbc9ff192a6c9 works This is a: processor : 11 vendor_id : AuthenticAMD cpu family : 25 model : 33 model name : AMD Ryzen 5 5600X 6-Core Processor stepping : 0 microcode : 0xa20102e Is something missing in 6.6.y and 6.12.y? Thomas

2 months

4
23
0 0

[REGRESSION]: fwd: regression in 6.15.5: KVM guest launch FAILSs with missing CPU feature error (sbpb, ibpb-brtype)

by pgnd

(already submitted @ Fedora; advised to post here to upstream as well) -------- Forwarded Message -------- Subject: regression in 6.15.5: KVM guest launch FAILSs with missing CPU feature error (sbpb, ibpb-brtype) Date: Sun, 13 Jul 2025 17:37:57 -0400 From: pgnd <pgnd(a)dev-mail.net> Reply-To: pgnd(a)dev-mail.net To: kernel(a)lists.fedoraproject.org i'm seeing a regression on Fedora 42 kernel 6.15.4 -> 6.15.5 on AMD Ryzen 5 5600G host (x86_64) kvm guests that launch ok under kernels 6.15.[3,4] fail with the following error when attempting to autostart under 6.15.5: internal error: Failed to autostart VM: operation failed: guest CPU doesn't match specification: missing features: sbpb,ibpb-brtype no changes made to libvirt, qemu, or VM defs between kernel versions. re-booting to old kernel versions restores expected behavior. maybe related (?) to recent changes in AMD CPU feature exposure / mitigation handling in kernel 6.15.5? i've opened a bug: https://bugzilla.redhat.com/show_bug.cgi?id=2379784

2 months

1
0
0 0

[PATCH] spi: Add check for 8-bit transfer with 8 IO mode support

by Cheng Ming Lin

From: Cheng Ming Lin <chengminglin(a)mxic.com.tw> The current SPI framework does not verify if the SPI device supports 8 IO mode when doing an 8-bit transfer. This patch adds a check to ensure that if the transfer tx_nbits or rx_nbits is 8, the SPI mode must support 8 IO. If not, an error is returned, preventing undefined behavior. Fixes: d6a711a898672 ("spi: Fix OCTAL mode support") Cc: stable(a)vger.kernel.org Signed-off-by: Cheng Ming Lin <chengminglin(a)mxic.com.tw> --- drivers/spi/spi.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 1bc0fdbb1bd7..0ffa3f9f2870 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -4138,10 +4138,13 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) xfer->tx_nbits != SPI_NBITS_OCTAL) return -EINVAL; if ((xfer->tx_nbits == SPI_NBITS_DUAL) && - !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) + !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) return -EINVAL; if ((xfer->tx_nbits == SPI_NBITS_QUAD) && - !(spi->mode & SPI_TX_QUAD)) + !(spi->mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) + return -EINVAL; + if ((xfer->tx_nbits == SPI_NBITS_OCTAL) && + !(spi->mode & SPI_TX_OCTAL)) return -EINVAL; } /* Check transfer rx_nbits */ @@ -4154,10 +4157,13 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) xfer->rx_nbits != SPI_NBITS_OCTAL) return -EINVAL; if ((xfer->rx_nbits == SPI_NBITS_DUAL) && - !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) + !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) return -EINVAL; if ((xfer->rx_nbits == SPI_NBITS_QUAD) && - !(spi->mode & SPI_RX_QUAD)) + !(spi->mode & (SPI_RX_QUAD | SPI_RX_OCTAL))) + return -EINVAL; + if ((xfer->rx_nbits == SPI_NBITS_OCTAL) && + !(spi->mode & SPI_RX_OCTAL)) return -EINVAL; } -- 2.25.1

2 months

2
1
0 0

[RFC V1 PATCH mm-hotfixes 1/3] mm: introduce and use {pgd,p4d}_populate_kernel()

by Harry Yoo

Intrdocue and use {pgd,p4d}_pouplate_kernel() in core MM code when populating PGD and P4D entries corresponding to the kernel address space. The main purpose of these helpers is to ensure synchronization of the kernel portion of the top-level page tables whenever such an entry is populated. Until now, the kernel has relied on each architecture to handle synchronization of top-level page tables in an ad-hoc manner. For example, see commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes"). However, this approach has proven fragile, as it's easy to forget to perform the necessary synchronization when introducing new changes. To address this, introduce _kernel() varients of the page table population helpers that invoke architecture-specific hooks to properly synchronize the page tables. For now, it only targets x86_64, so only PGD and P4D level helpers are introduced. In theory, PUD and PMD level helpers can be added later if needed by other architectures. Currently it is no-op as no arch defines __HAVE_ARCH_SYNC_KERNEL_PGTABLES. Cc: <stable(a)vger.kernel.org> Suggested-by: Dave Hansen <dave.hansen(a)linux.intel.com> Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> --- include/asm-generic/pgalloc.h | 4 ++++ include/linux/pgalloc.h | 0 mm/kasan/init.c | 10 +++++----- mm/percpu.c | 4 ++-- mm/sparse-vmemmap.c | 4 ++-- 5 files changed, 13 insertions(+), 9 deletions(-) create mode 100644 include/linux/pgalloc.h diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h index 3c8ec3bfea44..6cac1ce64e01 100644 --- a/include/asm-generic/pgalloc.h +++ b/include/asm-generic/pgalloc.h @@ -295,6 +295,10 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) __pgd_free(mm, pgd); } #endif +#ifndef __HAVE_ARCH_SYNC_KERNEL_PGTABLE +#define pgd_populate_kernel(addr, pgd, p4d) pgd_populate(&init_mm, pgd, p4d) +#define p4d_populate_kernel(addr, p4d, pud) p4d_populate(&init_mm, p4d, pud) +#endif #endif /* CONFIG_MMU */ diff --git a/include/linux/pgalloc.h b/include/linux/pgalloc.h new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/mm/kasan/init.c b/mm/kasan/init.c index ced6b29fcf76..43de820ee282 100644 --- a/mm/kasan/init.c +++ b/mm/kasan/init.c @@ -191,7 +191,7 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr, pud_t *pud; pmd_t *pmd; - p4d_populate(&init_mm, p4d, + p4d_populate_kernel(addr, p4d, lm_alias(kasan_early_shadow_pud)); pud = pud_offset(p4d, addr); pud_populate(&init_mm, pud, @@ -212,7 +212,7 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr, } else { p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); pud_init(p); - p4d_populate(&init_mm, p4d, p); + p4d_populate_kernel(addr, p4d, p); } } zero_pud_populate(p4d, addr, next); @@ -251,10 +251,10 @@ int __ref kasan_populate_early_shadow(const void *shadow_start, * puds,pmds, so pgd_populate(), pud_populate() * is noops. */ - pgd_populate(&init_mm, pgd, + pgd_populate_kernel(addr, pgd, lm_alias(kasan_early_shadow_p4d)); p4d = p4d_offset(pgd, addr); - p4d_populate(&init_mm, p4d, + p4d_populate_kernel(addr, p4d, lm_alias(kasan_early_shadow_pud)); pud = pud_offset(p4d, addr); pud_populate(&init_mm, pud, @@ -273,7 +273,7 @@ int __ref kasan_populate_early_shadow(const void *shadow_start, if (!p) return -ENOMEM; } else { - pgd_populate(&init_mm, pgd, + pgd_populate_kernel(addr, pgd, early_alloc(PAGE_SIZE, NUMA_NO_NODE)); } } diff --git a/mm/percpu.c b/mm/percpu.c index 782cc148b39c..57450a03c432 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -3134,13 +3134,13 @@ void __init __weak pcpu_populate_pte(unsigned long addr) if (pgd_none(*pgd)) { p4d = memblock_alloc_or_panic(P4D_TABLE_SIZE, P4D_TABLE_SIZE); - pgd_populate(&init_mm, pgd, p4d); + pgd_populate_kernel(addr, pgd, p4d); } p4d = p4d_offset(pgd, addr); if (p4d_none(*p4d)) { pud = memblock_alloc_or_panic(PUD_TABLE_SIZE, PUD_TABLE_SIZE); - p4d_populate(&init_mm, p4d, pud); + p4d_populate_kernel(addr, p4d, pud); } pud = pud_offset(p4d, addr); diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index fd2ab5118e13..e275310ac708 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -229,7 +229,7 @@ p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node) if (!p) return NULL; pud_init(p); - p4d_populate(&init_mm, p4d, p); + p4d_populate_kernel(addr, p4d, p); } return p4d; } @@ -241,7 +241,7 @@ pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node) void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); if (!p) return NULL; - pgd_populate(&init_mm, pgd, p); + pgd_populate_kernel(addr, pgd, p); } return pgd; } -- 2.43.0

2 months

3
5
0 0

Linux 6.12.38

by Greg Kroah-Hartman

I'm announcing the release of the 6.12.38 kernel. Only users of AMD x86-based processors need to upgrade, all others may skip this release. The updated 6.12.y git tree can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.12.y and can be browsed at the normal kernel.org git web browser: https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary thanks, greg k-h ------------ Makefile | 2 +- arch/x86/kernel/cpu/amd.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) Borislav Petkov (AMD) (1): x86/CPU/AMD: Properly check the TSA microcode Greg Kroah-Hartman (1): Linux 6.12.38

2 months

1
1
0 0

Linux 6.6.98

by Greg Kroah-Hartman

I'm announcing the release of the 6.6.98 kernel. Only users of AMD x86-based processors need to upgrade, all others may skip this release. The updated 6.6.y git tree can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.6.y and can be browsed at the normal kernel.org git web browser: https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary thanks, greg k-h ------------ Makefile | 2 +- arch/x86/kernel/cpu/amd.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) Borislav Petkov (AMD) (1): x86/CPU/AMD: Properly check the TSA microcode Greg Kroah-Hartman (1): Linux 6.6.98

2 months

1
1
0 0

Linux 6.1.145

by Greg Kroah-Hartman

I'm announcing the release of the 6.1.145 kernel. Only users of AMD x86-based processors need to upgrade, all others may skip this release. The updated 6.1.y git tree can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.1.y and can be browsed at the normal kernel.org git web browser: https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary thanks, greg k-h ------------ Makefile | 2 +- arch/x86/kernel/cpu/amd.c | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-) Borislav Petkov (AMD) (1): x86/CPU/AMD: Properly check the TSA microcode Greg Kroah-Hartman (1): Linux 6.1.145

2 months

1
1
0 0

Linux 5.15.188

by Greg Kroah-Hartman

I'm announcing the release of the 5.15.188 kernel. Only users of AMD x86-based processors need to upgrade, all others may skip this release. The updated 5.15.y git tree can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-5.15.y and can be browsed at the normal kernel.org git web browser: https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary thanks, greg k-h ------------ Makefile | 2 +- arch/x86/kernel/cpu/amd.c | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-) Borislav Petkov (AMD) (1): x86/CPU/AMD: Properly check the TSA microcode Greg Kroah-Hartman (1): Linux 5.15.188

2 months

1
1
0 0

FAILED: patch "[PATCH] x86/mm: Disable hugetlb page table sharing on 32-bit" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071423-imbecile-slander-d8e9@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Wed, 2 Jul 2025 10:32:04 +0200 Subject: [PATCH] x86/mm: Disable hugetlb page table sharing on 32-bit Only select ARCH_WANT_HUGE_PMD_SHARE on 64-bit x86. Page table sharing requires at least three levels because it involves shared references to PMD tables; 32-bit x86 has either two-level paging (without PAE) or three-level paging (with PAE), but even with three-level paging, having a dedicated PGD entry for hugetlb is only barely possible (because the PGD only has four entries), and it seems unlikely anyone's actually using PMD sharing on 32-bit. Having ARCH_WANT_HUGE_PMD_SHARE enabled on non-PAE 32-bit X86 (which has 2-level paging) became particularly problematic after commit 59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count"), since that changes `struct ptdesc` such that the `pt_mm` (for PGDs) and the `pt_share_count` (for PMDs) share the same union storage - and with 2-level paging, PMDs are PGDs. (For comparison, arm64 also gates ARCH_WANT_HUGE_PMD_SHARE on the configuration of page tables such that it is never enabled with 2-level paging.) Closes: https://lore.kernel.org/r/srhpjxlqfna67blvma5frmy3aa@altlinux.org Fixes: cfe28c5d63d8 ("x86: mm: Remove x86 version of huge_pmd_share.") Reported-by: Vitaly Chikunov <vt(a)altlinux.org> Suggested-by: Dave Hansen <dave.hansen(a)intel.com> Signed-off-by: Jann Horn <jannh(a)google.com> Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Acked-by: Oscar Salvador <osalvador(a)suse.de> Acked-by: David Hildenbrand <david(a)redhat.com> Tested-by: Vitaly Chikunov <vt(a)altlinux.org> Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250702-x86-2level-hugetlb-v2-1-1a98096edf92%4… diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 71019b3b54ea..4e0fe688cc83 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -147,7 +147,7 @@ config X86 select ARCH_WANTS_DYNAMIC_TASK_STRUCT select ARCH_WANTS_NO_INSTR select ARCH_WANT_GENERAL_HUGETLB - select ARCH_WANT_HUGE_PMD_SHARE + select ARCH_WANT_HUGE_PMD_SHARE if X86_64 select ARCH_WANT_LD_ORPHAN_WARN select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64

2 months

2
1
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror