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

[PATCH v2] net/handshake: restore destructor on submit failure

by caoping

handshake_req_submit() replaces sk->sk_destruct but never restores it when submission fails before the request is hashed. handshake_sk_destruct() then returns early and the original destructor never runs, leaking the socket. Restore sk_destruct on the error path. Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Signed-off-by: caoping <caoping(a)cmss.chinamobile.com> --- net/handshake/request.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/handshake/request.c b/net/handshake/request.c index 274d2c89b6b2..89435ed755cd 100644 --- a/net/handshake/request.c +++ b/net/handshake/request.c @@ -276,6 +276,8 @@ int handshake_req_submit(struct socket *sock, struct handshake_req *req, out_unlock: spin_unlock(&hn->hn_lock); out_err: + /* Restore original destructor so socket teardown still runs on failure */ + req->hr_sk->sk_destruct = req->hr_odestruct; trace_handshake_submit_err(net, req, req->hr_sk, ret); handshake_req_destroy(req); return ret; base-commit: 4a26e7032d7d57c998598c08a034872d6f0d3945 -- 2.47.3

3 days, 10 hours

2
1
0 0

[PATCH v2 2/2] kasan: Unpoison vms[area] addresses with a common tag

by Maciej Wieczor-Retman

From: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> A KASAN tag mismatch, possibly causing a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. It was reported on arm64 and reproduced on x86. It can be explained in the following points: 1. There can be more than one virtual memory chunk. 2. Chunk's base address has a tag. 3. The base address points at the first chunk and thus inherits the tag of the first chunk. 4. The subsequent chunks will be accessed with the tag from the first chunk. 5. Thus, the subsequent chunks need to have their tag set to match that of the first chunk. Use the modified __kasan_unpoison_vmalloc() to pass the tag of the first vm_struct's address when vm_structs are unpoisoned in pcpu_get_vm_areas(). Assigning a common tag resolves the pcpu chunk address mismatch. Fixes: 1d96320f8d53 ("kasan, vmalloc: add vmalloc tagging for SW_TAGS") Cc: <stable(a)vger.kernel.org> # 6.1+ Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> --- Changelog v2: - Revise the whole patch to match the fixed refactorization from the first patch. Changelog v1: - Rewrite the patch message to point at the user impact of the issue. - Move helper to common.c so it can be compiled in all KASAN modes. mm/kasan/common.c | 3 ++- mm/kasan/hw_tags.c | 12 ++++++++---- mm/kasan/shadow.c | 15 +++++++++++---- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 7884ea7d13f9..e5a867a5670b 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -591,11 +591,12 @@ void kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms, unsigned long size; void *addr; int area; + u8 tag = get_tag(vms[0]->addr); for (area = 0 ; area < nr_vms ; area++) { size = vms[area]->size; addr = vms[area]->addr; - vms[area]->addr = __kasan_unpoison_vmap_areas(addr, size, flags); + vms[area]->addr = __kasan_unpoison_vmap_areas(addr, size, flags, tag); } } #endif diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 4b7936a2bd6f..2a02b898b9d8 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -317,7 +317,7 @@ static void init_vmalloc_pages(const void *start, unsigned long size) } static void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, - kasan_vmalloc_flags_t flags) + kasan_vmalloc_flags_t flags, int unpoison_tag) { u8 tag; unsigned long redzone_start, redzone_size; @@ -361,7 +361,11 @@ static void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, return (void *)start; } - tag = kasan_random_tag(); + if (unpoison_tag < 0) + tag = kasan_random_tag(); + else + tag = unpoison_tag; + start = set_tag(start, tag); /* Unpoison and initialize memory up to size. */ @@ -390,7 +394,7 @@ static void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, void *__kasan_random_unpoison_vmalloc(const void *start, unsigned long size, kasan_vmalloc_flags_t flags) { - return __kasan_unpoison_vmalloc(start, size, flags); + return __kasan_unpoison_vmalloc(start, size, flags, -1); } void __kasan_poison_vmalloc(const void *start, unsigned long size) @@ -405,7 +409,7 @@ void __kasan_poison_vmalloc(const void *start, unsigned long size) void *__kasan_unpoison_vmap_areas(void *addr, unsigned long size, kasan_vmalloc_flags_t flags, u8 tag) { - return __kasan_unpoison_vmalloc(addr, size, flags); + return __kasan_unpoison_vmalloc(addr, size, flags, tag); } #endif diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 0a8d8bf6e9cf..7a66ffc1d5b3 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -625,8 +625,10 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end, } static void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, - kasan_vmalloc_flags_t flags) + kasan_vmalloc_flags_t flags, int unpoison_tag) { + u8 tag; + /* * Software KASAN modes unpoison both VM_ALLOC and non-VM_ALLOC * mappings, so the KASAN_VMALLOC_VM_ALLOC flag is ignored. @@ -648,7 +650,12 @@ static void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, !(flags & KASAN_VMALLOC_PROT_NORMAL)) return (void *)start; - start = set_tag(start, kasan_random_tag()); + if (unpoison_tag < 0) + tag = kasan_random_tag(); + else + tag = unpoison_tag; + + start = set_tag(start, tag); kasan_unpoison(start, size, false); return (void *)start; } @@ -656,13 +663,13 @@ static void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, void *__kasan_random_unpoison_vmalloc(const void *start, unsigned long size, kasan_vmalloc_flags_t flags) { - return __kasan_unpoison_vmalloc(start, size, flags); + return __kasan_unpoison_vmalloc(start, size, flags, -1); } void *__kasan_unpoison_vmap_areas(void *addr, unsigned long size, kasan_vmalloc_flags_t flags, u8 tag) { - return __kasan_unpoison_vmalloc(addr, size, flags); + return __kasan_unpoison_vmalloc(addr, size, flags, tag); } /* -- 2.52.0

3 days, 11 hours

3
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[PATCH 6.1] fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF

by Chen Yu

From: Baokun Li <libaokun1(a)huawei.com> commit 72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f upstream. The fscache_cookie_lru_timer is initialized when the fscache module is inserted, but is not deleted when the fscache module is removed. If timer_reduce() is called before removing the fscache module, the fscache_cookie_lru_timer will be added to the timer list of the current cpu. Afterwards, a use-after-free will be triggered in the softIRQ after removing the fscache module, as follows: ================================================================== BUG: unable to handle page fault for address: fffffbfff803c9e9 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855 Tainted: [W]=WARN RIP: 0010:__run_timer_base.part.0+0x254/0x8a0 Call Trace: <IRQ> tmigr_handle_remote_up+0x627/0x810 __walk_groups.isra.0+0x47/0x140 tmigr_handle_remote+0x1fa/0x2f0 handle_softirqs+0x180/0x590 irq_exit_rcu+0x84/0xb0 sysvec_apic_timer_interrupt+0x6e/0x90 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:default_idle+0xf/0x20 default_idle_call+0x38/0x60 do_idle+0x2b5/0x300 cpu_startup_entry+0x54/0x60 start_secondary+0x20d/0x280 common_startup_64+0x13e/0x148 </TASK> Modules linked in: [last unloaded: netfs] ================================================================== Therefore delete fscache_cookie_lru_timer when removing the fscahe module. Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning") Cc: stable(a)kernel.org Signed-off-by: Baokun Li <libaokun1(a)huawei.com> Link: https://lore.kernel.org/r/20240826112056.2458299-1-libaokun@huaweicloud.com Acked-by: David Howells <dhowells(a)redhat.com> Signed-off-by: Christian Brauner <brauner(a)kernel.org> [ Changed the file path due to missing commit:47757ea83a54 ("netfs, fscache: Move fs/fscache/* into fs/netfs/") ] Signed-off-by: Chen Yu <xnguchen(a)sina.cn> --- fs/fscache/main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/fscache/main.c b/fs/fscache/main.c index dad85fd84f6f..7a60cd96e87e 100644 --- a/fs/fscache/main.c +++ b/fs/fscache/main.c @@ -114,6 +114,7 @@ static void __exit fscache_exit(void) kmem_cache_destroy(fscache_cookie_jar); fscache_proc_cleanup(); + timer_shutdown_sync(&fscache_cookie_lru_timer); destroy_workqueue(fscache_wq); pr_notice("Unloaded\n"); } -- 2.17.1

3 days, 12 hours

1
0
0 0

[PATCH net v3 1/1] atm: mpoa: Fix UAF on qos_head list in procfs

by Minseong Kim

The global QoS list 'qos_head' in net/atm/mpc.c is accessed from the /proc/net/atm/mpc procfs interface without proper synchronization. The read-side seq_file show path (mpc_show() -> atm_mpoa_disp_qos()) walks qos_head without any lock, while the write-side path (proc_mpc_write() -> parse_qos() -> atm_mpoa_delete_qos()) can unlink and kfree() entries immediately. Concurrent read/write therefore leads to a use-after-free. Fix this by serializing all qos_head list operations with a mutex. A mutex is used because seq_printf() may sleep. To avoid returning an unprotected pointer (and the resulting lifetime race), replace atm_mpoa_search_qos() with atm_mpoa_get_qos(), which copies the QoS under lock. Also add atm_mpoa_delete_qos_by_ip() so search+unlink+free is atomic under the same lock, preventing concurrent double-free/UAF scenarios. KASAN report: [ 15.911538] BUG: KASAN: slab-use-after-free in atm_mpoa_disp_qos+0x202/0x380 [ 15.911988] Read of size 8 at addr ffff888007517380 by task mpoa_uaf_poc/89 [ 15.912123] [ 15.912717] CPU: 0 UID: 0 PID: 89 Comm: mpoa_uaf_poc Not tainted 6.17.8 #1 PREEMPT(voluntary) [ 15.912950] Hardware name: QEMU Ubuntu 25.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.913110] Call Trace: [ 15.913167] <TASK> [ 15.913247] dump_stack_lvl+0x4e/0x70 [ 15.913343] ? atm_mpoa_disp_qos+0x202/0x380 [ 15.913364] print_report+0x174/0x4f6 [ 15.913386] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 15.913412] ? atm_mpoa_disp_qos+0x202/0x380 [ 15.913430] kasan_report+0xce/0x100 [ 15.913453] ? atm_mpoa_disp_qos+0x202/0x380 [ 15.913475] atm_mpoa_disp_qos+0x202/0x380 [ 15.913496] mpc_show+0x575/0x700 [ 15.913515] ? kasan_save_track+0x14/0x30 [ 15.913532] ? __pfx_mpc_show+0x10/0x10 [ 15.913550] ? __pfx_mutex_lock+0x10/0x10 [ 15.913565] ? seq_read_iter+0x697/0x1110 [ 15.913584] seq_read_iter+0x2bc/0x1110 [ 15.913607] seq_read+0x267/0x3d0 [ 15.913623] ? __pfx_seq_read+0x10/0x10 [ 15.913650] proc_reg_read+0x1ab/0x270 [ 15.913669] vfs_read+0x175/0xa10 [ 15.913687] ? do_sys_openat2+0x103/0x170 [ 15.913701] ? kmem_cache_free+0xc4/0x360 [ 15.913718] ? getname_flags.part.0+0xf3/0x470 [ 15.913734] ? __pfx_vfs_read+0x10/0x10 [ 15.913751] ? mutex_lock+0x81/0xe0 [ 15.913766] ? __pfx_mutex_lock+0x10/0x10 [ 15.913782] ? __rseq_handle_notify_resume+0x4c4/0xac0 [ 15.913802] ? fdget_pos+0x24d/0x4b0 [ 15.913829] ksys_read+0xf7/0x1c0 [ 15.913850] ? __pfx_ksys_read+0x10/0x10 [ 15.913877] do_syscall_64+0xa4/0x290 [ 15.913917] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 15.913981] RIP: 0033:0x45c982 [ 15.914171] Code: 08 0f 85 71 ea ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 55 48 89 e5 [ 15.914239] RSP: 002b:00007f4b2b2cb0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 15.914315] RAX: ffffffffffffffda RBX: 00007f4b2b2cc6c0 RCX: 000000000045c982 [ 15.914352] RDX: 0000000000000fff RSI: 00007f4b2b2cb220 RDI: 0000000000000014 [ 15.914382] RBP: 00007f4b2b2cb100 R08: 0000000000000000 R09: 0000000000000000 [ 15.914413] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000a [ 15.914445] R13: ffffffffffffffd0 R14: 0000000000000000 R15: 00007ffd386450c0 [ 15.914483] </TASK> [ 15.914533] [ 15.916812] Allocated by task 78: [ 15.916975] kasan_save_stack+0x30/0x50 [ 15.917047] kasan_save_track+0x14/0x30 [ 15.917105] __kasan_kmalloc+0x8f/0xa0 [ 15.917162] atm_mpoa_add_qos+0x1bb/0x3c0 [ 15.917220] parse_qos.cold+0x73/0x7d [ 15.917276] proc_mpc_write+0xf4/0x150 [ 15.917331] proc_reg_write+0x1ab/0x270 [ 15.917379] vfs_write+0x1ce/0xd30 [ 15.917431] ksys_write+0xf7/0x1c0 [ 15.917476] do_syscall_64+0xa4/0x290 [ 15.917523] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 15.917586] [ 15.917628] Freed by task 78: [ 15.917665] kasan_save_stack+0x30/0x50 [ 15.917714] kasan_save_track+0x14/0x30 [ 15.917762] kasan_save_free_info+0x3b/0x70 [ 15.917811] __kasan_slab_free+0x3e/0x50 [ 15.918058] kfree+0x121/0x340 [ 15.918135] atm_mpoa_delete_qos+0xad/0xd0 [ 15.918196] parse_qos+0x1e5/0x1f0 [ 15.918339] proc_mpc_write+0xf4/0x150 [ 15.918438] proc_reg_write+0x1ab/0x270 [ 15.918494] vfs_write+0x1ce/0xd30 [ 15.918538] ksys_write+0xf7/0x1c0 [ 15.918589] do_syscall_64+0xa4/0x290 [ 15.918634] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 15.918694] [ 15.918751] The buggy address belongs to the object at ffff888007517380 [ 15.918751] which belongs to the cache kmalloc-96 of size 96 [ 15.918911] The buggy address is located 0 bytes inside of [ 15.918911] freed 96-byte region [ffff888007517380, ffff8880075173e0) [ 15.919027] [ 15.919101] The buggy address belongs to the physical page: [ 15.919416] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888007517300 pfn:0x7517 [ 15.919679] anon flags: 0x100000000000000(node=0|zone=1) [ 15.920064] page_type: f5(slab) [ 15.920361] raw: 0100000000000000 ffff888006c41280 0000000000000000 dead000000000001 [ 15.920460] raw: ffff888007517300 0000000080200007 00000000f5000000 0000000000000000 [ 15.920577] page dumped because: kasan: bad access detected [ 15.920634] [ 15.920663] Memory state around the buggy address: [ 15.920860] ffff888007517280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.920944] ffff888007517300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921017] >ffff888007517380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921088] ^ [ 15.921163] ffff888007517400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921222] ffff888007517480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc Reported-by: Minseong Kim <ii4gsp(a)gmail.com> Closes: https://lore.kernel.org/netdev/CAKrymDR1X3XTX_1ZW3XXXnuYH+kzsnv7Av5uivzR1st… Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable(a)vger.kernel.org Signed-off-by: Minseong Kim <ii4gsp(a)gmail.com> --- net/atm/mpc.c | 184 ++++++++++++++++++++++++++++++++---------- net/atm/mpc.h | 3 +- net/atm/mpoa_caches.c | 17 ++-- net/atm/mpoa_proc.c | 2 +- 4 files changed, 149 insertions(+), 57 deletions(-) diff --git a/net/atm/mpc.c b/net/atm/mpc.c index f6b447bba329..650081dd82d1 100644 --- a/net/atm/mpc.c +++ b/net/atm/mpc.c @@ -9,6 +9,7 @@ #include <linux/bitops.h> #include <linux/capability.h> #include <linux/seq_file.h> +#include <linux/mutex.h> /* We are an ethernet device */ #include <linux/if_ether.h> @@ -122,6 +123,7 @@ static struct notifier_block mpoa_notifier = { struct mpoa_client *mpcs = NULL; /* FIXME */ static struct atm_mpoa_qos *qos_head = NULL; +static DEFINE_MUTEX(qos_mutex); /* Protect qos_head list */ static DEFINE_TIMER(mpc_timer, mpc_cache_check); @@ -172,67 +174,63 @@ static struct mpoa_client *find_mpc_by_lec(struct net_device *dev) */ /* - * Overwrites the old entry or makes a new one. + * Search for a QoS entry. Caller must hold qos_mutex. + * Returns pointer to entry if found, NULL otherwise. */ -struct atm_mpoa_qos *atm_mpoa_add_qos(__be32 dst_ip, struct atm_qos *qos) +static struct atm_mpoa_qos *__atm_mpoa_search_qos(__be32 dst_ip) { - struct atm_mpoa_qos *entry; - - entry = atm_mpoa_search_qos(dst_ip); - if (entry != NULL) { - entry->qos = *qos; - return entry; - } + struct atm_mpoa_qos *qos = qos_head; - entry = kmalloc(sizeof(struct atm_mpoa_qos), GFP_KERNEL); - if (entry == NULL) { - pr_info("mpoa: out of memory\n"); - return entry; + while (qos) { + if (qos->ipaddr == dst_ip) + return qos; + qos = qos->next; } - - entry->ipaddr = dst_ip; - entry->qos = *qos; - - entry->next = qos_head; - qos_head = entry; - - return entry; + return NULL; } -struct atm_mpoa_qos *atm_mpoa_search_qos(__be32 dst_ip) +/* + * Get a QoS entry by copying its value. + * Caller gets a COPY of qos under lock. + * Returns true if found and copied, false if not found. + * This avoids lifetime issues with the returned pointer. + */ +bool atm_mpoa_get_qos(__be32 dst_ip, struct atm_qos *out) { - struct atm_mpoa_qos *qos; + struct atm_mpoa_qos *q; - qos = qos_head; - while (qos) { - if (qos->ipaddr == dst_ip) - break; - qos = qos->next; - } + if (!out) + return false; - return qos; + mutex_lock(&qos_mutex); + q = __atm_mpoa_search_qos(dst_ip); + if (q) + *out = q->qos; + mutex_unlock(&qos_mutex); + + return q; } /* - * Returns 0 for failure + * Delete a QoS entry from the list. Caller must hold qos_mutex. + * Returns 1 if found and deleted, 0 if not found. */ -int atm_mpoa_delete_qos(struct atm_mpoa_qos *entry) +static int __atm_mpoa_delete_qos_locked(struct atm_mpoa_qos *entry) { struct atm_mpoa_qos *curr; - if (entry == NULL) + if (!entry) return 0; + if (entry == qos_head) { - qos_head = qos_head->next; - kfree(entry); + qos_head = entry->next; return 1; } curr = qos_head; - while (curr != NULL) { + while (curr) { if (curr->next == entry) { curr->next = entry->next; - kfree(entry); return 1; } curr = curr->next; @@ -241,15 +239,107 @@ int atm_mpoa_delete_qos(struct atm_mpoa_qos *entry) return 0; } +/* + * Delete a QoS entry by IP address. + * This is atomic: search+unlink+free happens entirely under lock, + * avoiding the double-free issue with atm_mpoa_delete_qos(atm_mpoa_search_qos(ipaddr)). + */ +int atm_mpoa_delete_qos_by_ip(__be32 dst_ip) +{ + struct atm_mpoa_qos *entry; + int ret = 0; + + mutex_lock(&qos_mutex); + entry = __atm_mpoa_search_qos(dst_ip); + if (entry) { + ret = __atm_mpoa_delete_qos_locked(entry); + if (ret) + kfree(entry); + } + mutex_unlock(&qos_mutex); + + return ret; +} + +/* + * Overwrites the old entry or makes a new one. + */ +struct atm_mpoa_qos *atm_mpoa_add_qos(__be32 dst_ip, struct atm_qos *qos) +{ + struct atm_mpoa_qos *entry; + struct atm_mpoa_qos *new; + + /* Fast path: update existing entry */ + mutex_lock(&qos_mutex); + entry = __atm_mpoa_search_qos(dst_ip); + if (entry) { + entry->qos = *qos; + mutex_unlock(&qos_mutex); + return entry; + } + mutex_unlock(&qos_mutex); + + /* Allocate outside lock */ + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return NULL; + + new->ipaddr = dst_ip; + new->qos = *qos; + + /* Re-check under lock to avoid duplicates */ + mutex_lock(&qos_mutex); + entry = __atm_mpoa_search_qos(dst_ip); + if (entry) { + entry->qos = *qos; + mutex_unlock(&qos_mutex); + kfree(new); + return entry; + } + + new->next = qos_head; + qos_head = new; + mutex_unlock(&qos_mutex); + + return new; +} + +/* + * Delete a QoS entry by pointer. + * WARNING: This function is unsafe if called with an entry pointer + * obtained outside of qos_mutex protection. The entry may have been + * freed by another thread between the time the pointer was obtained + * and when this function is called. + * Use atm_mpoa_delete_qos_by_ip() instead for safe deletion by IP address. + * Returns 0 for failure, 1 for success + */ +int atm_mpoa_delete_qos(struct atm_mpoa_qos *entry) +{ + int ret; + + if (!entry) + return 0; + + mutex_lock(&qos_mutex); + ret = __atm_mpoa_delete_qos_locked(entry); + if (ret) + kfree(entry); + mutex_unlock(&qos_mutex); + + return ret; +} + /* this is buggered - we need locking for qos_head */ void atm_mpoa_disp_qos(struct seq_file *m) { struct atm_mpoa_qos *qos; - qos = qos_head; seq_printf(m, "QoS entries for shortcuts:\n"); - seq_printf(m, "IP address\n TX:max_pcr pcr min_pcr max_cdv max_sdu\n RX:max_pcr pcr min_pcr max_cdv max_sdu\n"); + seq_printf(m, "IP address\n TX:max_pcr pcr min_pcr max_cdv max_sdu\n" + " RX:max_pcr pcr min_pcr max_cdv max_sdu\n"); + mutex_lock(&qos_mutex); + qos = qos_head; while (qos != NULL) { seq_printf(m, "%pI4\n %-7d %-7d %-7d %-7d %-7d\n %-7d %-7d %-7d %-7d %-7d\n", &qos->ipaddr, @@ -265,6 +355,7 @@ void atm_mpoa_disp_qos(struct seq_file *m) qos->qos.rxtp.max_sdu); qos = qos->next; } + mutex_unlock(&qos_mutex); } static struct net_device *find_lec_by_itfnum(int itf) @@ -1118,13 +1209,16 @@ static void check_qos_and_open_shortcut(struct k_message *msg, in_cache_entry *entry) { __be32 dst_ip = msg->content.in_info.in_dst_ip; - struct atm_mpoa_qos *qos = atm_mpoa_search_qos(dst_ip); + struct atm_qos tmp_qos; + bool has_qos; eg_cache_entry *eg_entry = client->eg_ops->get_by_src_ip(dst_ip, client); + has_qos = atm_mpoa_get_qos(dst_ip, &tmp_qos); + if (eg_entry && eg_entry->shortcut) { if (eg_entry->shortcut->qos.txtp.traffic_class & msg->qos.txtp.traffic_class & - (qos ? qos->qos.txtp.traffic_class : ATM_UBR | ATM_CBR)) { + (has_qos ? tmp_qos.txtp.traffic_class : ATM_UBR | ATM_CBR)) { if (eg_entry->shortcut->qos.txtp.traffic_class == ATM_UBR) entry->shortcut = eg_entry->shortcut; else if (eg_entry->shortcut->qos.txtp.max_pcr > 0) @@ -1142,9 +1236,9 @@ static void check_qos_and_open_shortcut(struct k_message *msg, /* No luck in the egress cache we must open an ingress SVC */ msg->type = OPEN_INGRESS_SVC; - if (qos && - (qos->qos.txtp.traffic_class == msg->qos.txtp.traffic_class)) { - msg->qos = qos->qos; + if (has_qos && + tmp_qos.txtp.traffic_class == msg->qos.txtp.traffic_class) { + msg->qos = tmp_qos; pr_info("(%s) trying to get a CBR shortcut\n", client->dev->name); } else @@ -1521,8 +1615,10 @@ static void __exit atm_mpoa_cleanup(void) mpc = tmp; } + mutex_lock(&qos_mutex); qos = qos_head; qos_head = NULL; + mutex_unlock(&qos_mutex); while (qos != NULL) { nextqos = qos->next; dprintk("freeing qos entry %p\n", qos); diff --git a/net/atm/mpc.h b/net/atm/mpc.h index 454abd07651a..0536946989ad 100644 --- a/net/atm/mpc.h +++ b/net/atm/mpc.h @@ -47,8 +47,9 @@ struct atm_mpoa_qos { /* MPOA QoS operations */ struct atm_mpoa_qos *atm_mpoa_add_qos(__be32 dst_ip, struct atm_qos *qos); -struct atm_mpoa_qos *atm_mpoa_search_qos(__be32 dst_ip); +bool atm_mpoa_get_qos(__be32 dst_ip, struct atm_qos *out); int atm_mpoa_delete_qos(struct atm_mpoa_qos *qos); +int atm_mpoa_delete_qos_by_ip(__be32 dst_ip); /* Display QoS entries. This is for the procfs */ struct seq_file; diff --git a/net/atm/mpoa_caches.c b/net/atm/mpoa_caches.c index f7a2f0e41105..30c5b10ee562 100644 --- a/net/atm/mpoa_caches.c +++ b/net/atm/mpoa_caches.c @@ -132,7 +132,6 @@ static in_cache_entry *in_cache_add_entry(__be32 dst_ip, static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc) { - struct atm_mpoa_qos *qos; struct k_message msg; entry->count++; @@ -144,9 +143,8 @@ static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc) msg.type = SND_MPOA_RES_RQST; msg.content.in_info = entry->ctrl_info; memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN); - qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip); - if (qos != NULL) - msg.qos = qos->qos; + if (!atm_mpoa_get_qos(entry->ctrl_info.in_dst_ip, &msg.qos)) + memset(&msg.qos, 0, sizeof(msg.qos)); msg_to_mpoad(&msg, mpc); entry->reply_wait = ktime_get_seconds(); entry->entry_state = INGRESS_RESOLVING; @@ -167,9 +165,8 @@ static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc) msg.type = SND_MPOA_RES_RQST; memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN); msg.content.in_info = entry->ctrl_info; - qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip); - if (qos != NULL) - msg.qos = qos->qos; + if (!atm_mpoa_get_qos(entry->ctrl_info.in_dst_ip, &msg.qos)) + memset(&msg.qos, 0, sizeof(msg.qos)); msg_to_mpoad(&msg, mpc); entry->reply_wait = ktime_get_seconds(); } @@ -249,7 +246,6 @@ static void clear_count_and_expired(struct mpoa_client *client) static void check_resolving_entries(struct mpoa_client *client) { - struct atm_mpoa_qos *qos; in_cache_entry *entry; time64_t now; struct k_message msg; @@ -283,9 +279,8 @@ static void check_resolving_entries(struct mpoa_client *client) msg.type = SND_MPOA_RES_RTRY; memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN); msg.content.in_info = entry->ctrl_info; - qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip); - if (qos != NULL) - msg.qos = qos->qos; + if (!atm_mpoa_get_qos(entry->ctrl_info.in_dst_ip, &msg.qos)) + memset(&msg.qos, 0, sizeof(msg.qos)); msg_to_mpoad(&msg, client); entry->reply_wait = ktime_get_seconds(); } diff --git a/net/atm/mpoa_proc.c b/net/atm/mpoa_proc.c index aaf64b953915..600075c6022e 100644 --- a/net/atm/mpoa_proc.c +++ b/net/atm/mpoa_proc.c @@ -254,7 +254,7 @@ static int parse_qos(const char *buff) if (sscanf(buff, "del %hhu.%hhu.%hhu.%hhu", ip, ip+1, ip+2, ip+3) == 4) { ipaddr = *(__be32 *)ip; - return atm_mpoa_delete_qos(atm_mpoa_search_qos(ipaddr)); + return atm_mpoa_delete_qos_by_ip(ipaddr); } if (sscanf(buff, "add %hhu.%hhu.%hhu.%hhu tx=%d,%d rx=tx", -- 2.39.5 (Apple Git-154)

3 days, 12 hours

1
0
0 0

[PATCH v6.12 0/4] sched: The newidle balance regression

by Ajay Kaher

This series is to backport following patches for v6.12: link: https://lore.kernel.org/lkml/20251107160645.929564468@infradead.org/ Peter Zijlstra (3): sched/fair: Revert max_newidle_lb_cost bump sched/fair: Small cleanup to sched_balance_newidle() sched/fair: Small cleanup to update_newidle_cost() sched/fair: Proportional newidle balance include/linux/sched/topology.h | 3 ++ kernel/sched/core.c | 3 ++ kernel/sched/fair.c | 74 +++++++++++++++++++++++----------- kernel/sched/features.h | 5 +++ kernel/sched/sched.h | 7 ++++ kernel/sched/topology.c | 6 +++ 6 files changed, 75 insertions(+), 23 deletions(-) -- 2.40.4

3 days, 13 hours

2
7
0 0

[PATCH net v2 1/1] atm: mpoa: Fix UAF on qos_head list in procfs

by Minseong Kim

The global QoS list 'qos_head' in net/atm/mpc.c is accessed from the /proc/net/atm/mpc procfs interface without proper synchronization. The read-side seq_file show path (mpc_show() -> atm_mpoa_disp_qos()) walks qos_head without any lock, while the write-side path (proc_mpc_write() -> parse_qos() -> atm_mpoa_delete_qos()) can unlink and kfree() entries immediately. Concurrent read/write therefore leads to a use-after-free. This risk is already called out in-tree: /* this is buggered - we need locking for qos_head */ Fix this by adding a mutex to protect all qos_head list operations. A mutex is used (instead of a spinlock) because atm_mpoa_disp_qos() invokes seq_printf(), which may sleep. KASAN report: ================================================================== [ 15.911538] BUG: KASAN: slab-use-after-free in atm_mpoa_disp_qos+0x202/0x380 [ 15.911988] Read of size 8 at addr ffff888007517380 by task mpoa_uaf_poc/89 [ 15.912123] [ 15.912717] CPU: 0 UID: 0 PID: 89 Comm: mpoa_uaf_poc Not tainted 6.17.8 #1 PREEMPT(voluntary) [ 15.912950] Hardware name: QEMU Ubuntu 25.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.913110] Call Trace: [ 15.913167] <TASK> [ 15.913247] dump_stack_lvl+0x4e/0x70 [ 15.913343] ? atm_mpoa_disp_qos+0x202/0x380 [ 15.913364] print_report+0x174/0x4f6 [ 15.913386] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 15.913412] ? atm_mpoa_disp_qos+0x202/0x380 [ 15.913430] kasan_report+0xce/0x100 [ 15.913453] ? atm_mpoa_disp_qos+0x202/0x380 [ 15.913475] atm_mpoa_disp_qos+0x202/0x380 [ 15.913496] mpc_show+0x575/0x700 [ 15.913515] ? kasan_save_track+0x14/0x30 [ 15.913532] ? __pfx_mpc_show+0x10/0x10 [ 15.913550] ? __pfx_mutex_lock+0x10/0x10 [ 15.913565] ? seq_read_iter+0x697/0x1110 [ 15.913584] seq_read_iter+0x2bc/0x1110 [ 15.913607] seq_read+0x267/0x3d0 [ 15.913623] ? __pfx_seq_read+0x10/0x10 [ 15.913650] proc_reg_read+0x1ab/0x270 [ 15.913669] vfs_read+0x175/0xa10 [ 15.913687] ? do_sys_openat2+0x103/0x170 [ 15.913701] ? kmem_cache_free+0xc4/0x360 [ 15.913718] ? getname_flags.part.0+0xf3/0x470 [ 15.913734] ? __pfx_vfs_read+0x10/0x10 [ 15.913751] ? mutex_lock+0x81/0xe0 [ 15.913766] ? __pfx_mutex_lock+0x10/0x10 [ 15.913782] ? __rseq_handle_notify_resume+0x4c4/0xac0 [ 15.913802] ? fdget_pos+0x24d/0x4b0 [ 15.913829] ksys_read+0xf7/0x1c0 [ 15.913850] ? __pfx_ksys_read+0x10/0x10 [ 15.913877] do_syscall_64+0xa4/0x290 [ 15.913917] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 15.913981] RIP: 0033:0x45c982 [ 15.914171] Code: 08 0f 85 71 ea ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 55 48 89 e5 [ 15.914239] RSP: 002b:00007f4b2b2cb0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 15.914315] RAX: ffffffffffffffda RBX: 00007f4b2b2cc6c0 RCX: 000000000045c982 [ 15.914352] RDX: 0000000000000fff RSI: 00007f4b2b2cb220 RDI: 0000000000000014 [ 15.914382] RBP: 00007f4b2b2cb100 R08: 0000000000000000 R09: 0000000000000000 [ 15.914413] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000a [ 15.914445] R13: ffffffffffffffd0 R14: 0000000000000000 R15: 00007ffd386450c0 [ 15.914483] </TASK> [ 15.914533] [ 15.916812] Allocated by task 78: [ 15.916975] kasan_save_stack+0x30/0x50 [ 15.917047] kasan_save_track+0x14/0x30 [ 15.917105] __kasan_kmalloc+0x8f/0xa0 [ 15.917162] atm_mpoa_add_qos+0x1bb/0x3c0 [ 15.917220] parse_qos.cold+0x73/0x7d [ 15.917276] proc_mpc_write+0xf4/0x150 [ 15.917331] proc_reg_write+0x1ab/0x270 [ 15.917379] vfs_write+0x1ce/0xd30 [ 15.917431] ksys_write+0xf7/0x1c0 [ 15.917476] do_syscall_64+0xa4/0x290 [ 15.917523] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 15.917586] [ 15.917628] Freed by task 78: [ 15.917665] kasan_save_stack+0x30/0x50 [ 15.917714] kasan_save_track+0x14/0x30 [ 15.917762] kasan_save_free_info+0x3b/0x70 [ 15.917811] __kasan_slab_free+0x3e/0x50 [ 15.918058] kfree+0x121/0x340 [ 15.918135] atm_mpoa_delete_qos+0xad/0xd0 [ 15.918196] parse_qos+0x1e5/0x1f0 [ 15.918339] proc_mpc_write+0xf4/0x150 [ 15.918438] proc_reg_write+0x1ab/0x270 [ 15.918494] vfs_write+0x1ce/0xd30 [ 15.918538] ksys_write+0xf7/0x1c0 [ 15.918589] do_syscall_64+0xa4/0x290 [ 15.918634] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 15.918694] [ 15.918751] The buggy address belongs to the object at ffff888007517380 [ 15.918751] which belongs to the cache kmalloc-96 of size 96 [ 15.918911] The buggy address is located 0 bytes inside of [ 15.918911] freed 96-byte region [ffff888007517380, ffff8880075173e0) [ 15.919027] [ 15.919101] The buggy address belongs to the physical page: [ 15.919416] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888007517300 pfn:0x7517 [ 15.919679] anon flags: 0x100000000000000(node=0|zone=1) [ 15.920064] page_type: f5(slab) [ 15.920361] raw: 0100000000000000 ffff888006c41280 0000000000000000 dead000000000001 [ 15.920460] raw: ffff888007517300 0000000080200007 00000000f5000000 0000000000000000 [ 15.920577] page dumped because: kasan: bad access detected [ 15.920634] [ 15.920663] Memory state around the buggy address: [ 15.920860] ffff888007517280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.920944] ffff888007517300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921017] >ffff888007517380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921088] ^ [ 15.921163] ffff888007517400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921222] ffff888007517480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 15.921313] ================================================================== Reported-by: Minseong Kim <ii4gsp(a)gmail.com> Closes: https://lore.kernel.org/netdev/CAKrymDR1X3XTX_1ZW3XXXnuYH+kzsnv7Av5uivzR1st… Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable(a)vger.kernel.org Signed-off-by: Minseong Kim <ii4gsp(a)gmail.com> --- net/atm/mpc.c | 117 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 85 insertions(+), 32 deletions(-) diff --git a/net/atm/mpc.c b/net/atm/mpc.c index f6b447bba329..c268b5f4a266 100644 --- a/net/atm/mpc.c +++ b/net/atm/mpc.c @@ -9,6 +9,7 @@ #include <linux/bitops.h> #include <linux/capability.h> #include <linux/seq_file.h> +#include <linux/mutex.h> /* We are an ethernet device */ #include <linux/if_ether.h> @@ -122,6 +123,7 @@ static struct notifier_block mpoa_notifier = { struct mpoa_client *mpcs = NULL; /* FIXME */ static struct atm_mpoa_qos *qos_head = NULL; +static DEFINE_MUTEX(qos_mutex); /* Protect qos_head list */ static DEFINE_TIMER(mpc_timer, mpc_cache_check); @@ -171,74 +173,120 @@ static struct mpoa_client *find_mpc_by_lec(struct net_device *dev) * Functions for managing QoS list */ +/* + * Search for a QoS entry. Caller must hold qos_mutex. + * Returns pointer to entry if found, NULL otherwise. + */ +static struct atm_mpoa_qos *__atm_mpoa_search_qos(__be32 dst_ip) +{ + struct atm_mpoa_qos *qos = qos_head; + + while (qos) { + if (qos->ipaddr == dst_ip) + return qos; + qos = qos->next; + } + return NULL; +} + +/* + * Search for a QoS entry. + * WARNING: The returned pointer is not protected. The caller must ensure + * that the entry is not freed while using it, or hold qos_mutex during use. + */ +struct atm_mpoa_qos *atm_mpoa_search_qos(__be32 dst_ip) +{ + struct atm_mpoa_qos *qos; + + mutex_lock(&qos_mutex); + qos = __atm_mpoa_search_qos(dst_ip); + mutex_unlock(&qos_mutex); + + return qos; +} + /* * Overwrites the old entry or makes a new one. */ struct atm_mpoa_qos *atm_mpoa_add_qos(__be32 dst_ip, struct atm_qos *qos) { struct atm_mpoa_qos *entry; + struct atm_mpoa_qos *new; - entry = atm_mpoa_search_qos(dst_ip); - if (entry != NULL) { + /* Fast path: update existing entry */ + mutex_lock(&qos_mutex); + entry = __atm_mpoa_search_qos(dst_ip); + if (entry) { entry->qos = *qos; + mutex_unlock(&qos_mutex); return entry; } + mutex_unlock(&qos_mutex); - entry = kmalloc(sizeof(struct atm_mpoa_qos), GFP_KERNEL); - if (entry == NULL) { + /* Allocate outside lock */ + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) { pr_info("mpoa: out of memory\n"); - return entry; + return NULL; } - entry->ipaddr = dst_ip; - entry->qos = *qos; + new->ipaddr = dst_ip; + new->qos = *qos; - entry->next = qos_head; - qos_head = entry; - - return entry; -} - -struct atm_mpoa_qos *atm_mpoa_search_qos(__be32 dst_ip) -{ - struct atm_mpoa_qos *qos; - - qos = qos_head; - while (qos) { - if (qos->ipaddr == dst_ip) - break; - qos = qos->next; + /* Re-check under lock to avoid duplicates */ + mutex_lock(&qos_mutex); + entry = __atm_mpoa_search_qos(dst_ip); + if (entry) { + entry->qos = *qos; + mutex_unlock(&qos_mutex); + kfree(new); + return entry; } - return qos; + new->next = qos_head; + qos_head = new; + mutex_unlock(&qos_mutex); + + return new; } /* - * Returns 0 for failure + * Returns 0 for failure, 1 for success */ int atm_mpoa_delete_qos(struct atm_mpoa_qos *entry) { struct atm_mpoa_qos *curr; + int ret = 0; if (entry == NULL) return 0; + + mutex_lock(&qos_mutex); + if (entry == qos_head) { qos_head = qos_head->next; - kfree(entry); - return 1; + ret = 1; + goto out_free; } curr = qos_head; - while (curr != NULL) { + while (curr) { if (curr->next == entry) { curr->next = entry->next; - kfree(entry); - return 1; + ret = 1; + goto out_free; } curr = curr->next; } - return 0; +out: + mutex_unlock(&qos_mutex); + return ret; + +out_free: + mutex_unlock(&qos_mutex); + kfree(entry); + return ret; } /* this is buggered - we need locking for qos_head */ @@ -246,10 +294,12 @@ void atm_mpoa_disp_qos(struct seq_file *m) { struct atm_mpoa_qos *qos; - qos = qos_head; seq_printf(m, "QoS entries for shortcuts:\n"); - seq_printf(m, "IP address\n TX:max_pcr pcr min_pcr max_cdv max_sdu\n RX:max_pcr pcr min_pcr max_cdv max_sdu\n"); + seq_printf(m, "IP address\n TX:max_pcr pcr min_pcr max_cdv max_sdu\n" + " RX:max_pcr pcr min_pcr max_cdv max_sdu\n"); + mutex_lock(&qos_mutex); + qos = qos_head; while (qos != NULL) { seq_printf(m, "%pI4\n %-7d %-7d %-7d %-7d %-7d\n %-7d %-7d %-7d %-7d %-7d\n", &qos->ipaddr, @@ -265,6 +315,7 @@ void atm_mpoa_disp_qos(struct seq_file *m) qos->qos.rxtp.max_sdu); qos = qos->next; } + mutex_unlock(&qos_mutex); } static struct net_device *find_lec_by_itfnum(int itf) @@ -1521,8 +1572,10 @@ static void __exit atm_mpoa_cleanup(void) mpc = tmp; } + mutex_lock(&qos_mutex); qos = qos_head; qos_head = NULL; + mutex_unlock(&qos_mutex); while (qos != NULL) { nextqos = qos->next; dprintk("freeing qos entry %p\n", qos); -- 2.39.5 (Apple Git-154)

3 days, 14 hours

1
0
0 0

[REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

by KernelCI bot

Hello, New build issue found on stable-rc/linux-6.12.y: --- variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] in drivers/staging/rtl8712/rtl8712_cmd.o (drivers/staging/rtl8712/rtl8712_cmd.c) [logspec:kbuild,kbuild.compiler.error] --- - dashboard: https://d.kernelci.org/i/maestro:5b83acc62508c670164c5fceb3079a2d7d74e154 - giturl: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git - commit HEAD: d5dc97879a97b328a89ec092271faa3db9f2bff3 - tags: v6.12.59 Log excerpt: ===================================================== drivers/staging/rtl8712/rtl8712_cmd.c:148:28: error: variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 148 | memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz); | ^~~ 1 error generated. ===================================================== # Builds where the incident occurred: ## defconfig+allmodconfig on (arm64): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-arm64-allmodconfig-6924331af5b87… - dashboard: https://d.kernelci.org/build/maestro:6924331af5b8743b1f5e538f ## defconfig+allmodconfig+CONFIG_FRAME_WARN=2048 on (arm): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-arm-allmodconfig-69243317f5b8743… - dashboard: https://d.kernelci.org/build/maestro:69243317f5b8743b1f5e538c ## i386_defconfig+allmodconfig+CONFIG_FRAME_WARN=2048 on (i386): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-i386-allmodconfig-69243353f5b874… - dashboard: https://d.kernelci.org/build/maestro:69243353f5b8743b1f5e53bf ## x86_64_defconfig+allmodconfig on (x86_64): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-x86-allmodconfig-69243323f5b8743… - dashboard: https://d.kernelci.org/build/maestro:69243323f5b8743b1f5e5395 #kernelci issue maestro:5b83acc62508c670164c5fceb3079a2d7d74e154 Reported-by: kernelci.org bot <bot(a)kernelci.org> -- This is an experimental report format. Please send feedback in! Talk to us at kernelci(a)lists.linux.dev Made with love by the KernelCI team - https://kernelci.org

3 days, 16 hours

4
7
0 0

[PATCH AUTOSEL 6.18-6.6] iomap: adjust read range correctly for non-block-aligned positions

by Sasha Levin

From: Joanne Koong <joannelkoong(a)gmail.com> [ Upstream commit 7aa6bc3e8766990824f66ca76c19596ce10daf3e ] iomap_adjust_read_range() assumes that the position and length passed in are block-aligned. This is not always the case however, as shown in the syzbot generated case for erofs. This causes too many bytes to be skipped for uptodate blocks, which results in returning the incorrect position and length to read in. If all the blocks are uptodate, this underflows length and returns a position beyond the folio. Fix the calculation to also take into account the block offset when calculating how many bytes can be skipped for uptodate blocks. Signed-off-by: Joanne Koong <joannelkoong(a)gmail.com> Tested-by: syzbot(a)syzkaller.appspotmail.com Reviewed-by: Brian Foster <bfoster(a)redhat.com> Reviewed-by: Christoph Hellwig <hch(a)lst.de> Signed-off-by: Christian Brauner <brauner(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: Now I have all the information needed for a comprehensive analysis. Let me compile my findings. --- ## COMPREHENSIVE ANALYSIS: iomap_adjust_read_range() Bug Fix ### 1. COMMIT MESSAGE ANALYSIS **Subject:** `iomap: adjust read range correctly for non-block-aligned positions` **Key Points from Message:** - The function `iomap_adjust_read_range()` **assumes block-aligned positions**, but this assumption is violated - Bug was discovered via **syzbot testing with erofs** filesystem - Causes "too many bytes to be skipped for uptodate blocks" - Results in **incorrect position and length to read** - If all blocks are uptodate: **underflows length** and **returns position beyond the folio** **Tags Analysis:** - ✅ `Tested-by: syzbot(a)syzkaller.appspotmail.com` - Automated testing confirmed - ✅ `Reviewed-by: Brian Foster <bfoster(a)redhat.com>` - Red Hat filesystem expert - ✅ `Reviewed-by: Christoph Hellwig <hch(a)lst.de>` - Major iomap author - ✅ `Signed-off-by: Christian Brauner <brauner(a)kernel.org>` - VFS maintainer - ❌ **No `Cc: stable(a)vger.kernel.org`** tag - ❌ **No `Fixes:` tag** pointing to original buggy commit ### 2. CODE CHANGE ANALYSIS **Bug Location:** `fs/iomap/buffered-io.c`, function `iomap_adjust_read_range()` **The Buggy Code (lines 246-253 before fix):** ```c for (i = first; i <= last; i++) { if (!ifs_block_is_uptodate(ifs, i)) break; *pos += block_size; // Bug: assumes pos is block-aligned poff += block_size; plen -= block_size; first++; } ``` **Technical Root Cause:** When `*pos` has a sub-block offset (e.g., `pos = 512` in a 1024-byte block): - `first = poff >> block_bits` computes the block index correctly (block 0) - But the loop skips a full `block_size` per block, ignoring the offset **Example demonstrating the bug:** - Block size: 1024 bytes - Position: 512 (half-way into block 0) - Block 0 is uptodate **Old buggy calculation:** - Skip full 1024 bytes → `pos = 1536`, overshoots by 512 bytes - `plen -= 1024` → underflows if `plen < 1024` **Fixed calculation:** ```c blocks_skipped = i - first; if (blocks_skipped) { unsigned long block_offset = *pos & (block_size - 1); // = 512 unsigned bytes_skipped = (blocks_skipped << block_bits) - block_offset; // = 1024 - 512 = 512 *pos += bytes_skipped; // Correct: pos = 1024 poff += bytes_skipped; plen -= bytes_skipped; } ``` **Consequences of the Bug:** 1. **Integer underflow**: `plen` becomes huge (wraps around as unsigned) 2. **Position beyond folio**: `*pos` can point past the folio boundary 3. **Incorrect read ranges**: Wrong data read, potential corruption 4. **Potential crashes**: Invalid memory access from bad ranges ### 3. CLASSIFICATION - **Type:** BUG FIX (arithmetic/logic error causing incorrect calculations) - **NOT:** Feature addition, cleanup, or optimization - **Severity:** HIGH - affects filesystem data integrity - **Scope:** Core iomap buffered I/O infrastructure ### 4. SCOPE AND RISK ASSESSMENT **Change Size:** - 13 insertions, 6 deletions - Single file: `fs/iomap/buffered-io.c` - Localized to one function **Risk Level:** LOW - Fix is mathematically straightforward - Does not change control flow significantly - Well-reviewed by iomap experts - Tested by syzbot **Affected Subsystem:** `fs/iomap/` - mature, widely-used infrastructure **Affected Filesystems:** Multiple major filesystems use iomap: - **XFS** - Primary enterprise Linux filesystem - **GFS2** - Cluster filesystem - **erofs** - Read-only filesystem (Android) - **zonefs** - Zoned storage filesystem - **fuse** - User-space filesystems ### 5. USER IMPACT **Who is affected?** - ALL users of XFS, GFS2, erofs, zonefs, and fuse filesystems - Particularly affects systems with: - Block sizes smaller than page size - Partial folio reads/writes at non-block-aligned offsets **How severe?** - Can cause **incorrect data reads** - Potential **data corruption** in read paths - Possible **kernel crashes** from invalid memory access - **Data integrity** issues for critical filesystems **Triggered by:** syzbot (automated fuzzing) - confirms this is a real triggerable bug ### 6. STABILITY INDICATORS - ✅ `Tested-by: syzbot` - Confirmed fix works - ✅ Two expert reviewers (Brian Foster, Christoph Hellwig) - ✅ Merged by VFS maintainer (Christian Brauner) - ⚠️ Relatively new commit (September 2025) ### 7. DEPENDENCY CHECK **Bug Origin:** Commit `9dc55f1389f95` ("iomap: add support for sub- pagesize buffered I/O without buffer heads") from **v4.19-rc1** (2018) **Dependencies for backport:** - The fix is self-contained - May need minor adaptation for older kernels: - v5.x: Uses `struct iomap_page` and pages (not folios) - v6.x: Uses `struct iomap_folio_state` and folios - Core logic remains the same across versions **Related commits:** - `8e3c15ee0d292` - Minor loop syntax change (`for` → `while`), NOT a dependency - `9d875e0eef8ec` - Related fix for unaligned END offsets (separate issue) ### 8. HISTORICAL CONTEXT The bug has existed for **~6 years** (since v4.19). It was latent because: - Most callers pass block-aligned positions - erofs triggered an edge case with non-aligned positions - syzbot's extensive testing exposed it The original code assumed callers would always pass block-aligned positions, which is a reasonable assumption violated in specific edge cases. --- ## BACKPORT RECOMMENDATION ### Arguments FOR backporting: 1. **Fixes a real bug** discovered by automated testing (syzbot) 2. **Affects critical filesystems** (XFS, GFS2) used in production 3. **Small, surgical fix** - 13 lines added, 6 removed 4. **Low regression risk** - mathematically correct fix 5. **Expert-reviewed** by iomap maintainers 6. **Bug existed since v4.19** - all stable trees are affected 7. **Can cause data integrity issues** - serious for a filesystem bug ### Arguments AGAINST backporting: 1. **No `Cc: stable` tag** - maintainers didn't explicitly request backport 2. **No `Fixes:` tag** - doesn't identify the buggy commit 3. **Relatively new commit** - hasn't had extensive mainline testing yet 4. **Needs adaptation** for older kernels (page vs folio APIs) ### Conclusion: Despite the missing stable tags, this commit should be backported because: - It fixes a **real, triggerable bug** found by syzbot - The bug can cause **incorrect data reads and potential corruption** - It affects **major filesystems** (XFS, GFS2) used in production environments - The fix is **small, contained, and well-reviewed** - The **risk of NOT fixing** (data corruption) outweighs the risk of the fix (minimal) The absence of `Cc: stable` may be an oversight, as this clearly meets stable criteria. **YES** fs/iomap/buffered-io.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 8b847a1e27f13..1c95a0a7b302d 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -240,17 +240,24 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, * to avoid reading in already uptodate ranges. */ if (ifs) { - unsigned int i; + unsigned int i, blocks_skipped; /* move forward for each leading block marked uptodate */ - for (i = first; i <= last; i++) { + for (i = first; i <= last; i++) if (!ifs_block_is_uptodate(ifs, i)) break; - *pos += block_size; - poff += block_size; - plen -= block_size; - first++; + + blocks_skipped = i - first; + if (blocks_skipped) { + unsigned long block_offset = *pos & (block_size - 1); + unsigned bytes_skipped = + (blocks_skipped << block_bits) - block_offset; + + *pos += bytes_skipped; + poff += bytes_skipped; + plen -= bytes_skipped; } + first = i; /* truncate len if we find any trailing uptodate block(s) */ while (++i <= last) { -- 2.51.0

3 days, 19 hours

2
1
0 0

[PATCH] cifs: Fix handling of a beyond-EOF DIO/unbuffered read over SMB1

by David Howells

If a DIO read or an unbuffered read request extends beyond the EOF, the server will return a short read and a status code indicating that EOF was hit, which gets translated to -ENODATA. Note that the client does not cap the request at i_size, but asks for the amount requested in case there's a race on the server with a third party. Now, on the client side, the request will get split into multiple subrequests if rsize is smaller than the full request size. A subrequest that starts before or at the EOF and returns short data up to the EOF will be correctly handled, with the NETFS_SREQ_HIT_EOF flag being set, indicating to netfslib that we can't read more. If a subrequest, however, starts after the EOF and not at it, HIT_EOF will not be flagged, its error will be set to -ENODATA and it will be abandoned. This will cause the request as a whole to fail with -ENODATA. Fix this by setting NETFS_SREQ_HIT_EOF on any subrequest that lies beyond the EOF marker. This can be reproduced by mounting with "cache=none,sign,vers=1.0" and doing a read of a file that's significantly bigger than the size of the file (e.g. attempting to read 64KiB from a 16KiB file). Fixes: a68c74865f51 ("cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3") Signed-off-by: David Howells <dhowells(a)redhat.com> cc: Steve French <sfrench(a)samba.org> cc: Paulo Alcantara <pc(a)manguebit.org> cc: Shyam Prasad N <sprasad(a)microsoft.com> cc: linux-cifs(a)vger.kernel.org cc: netfs(a)lists.linux.dev cc: linux-fsdevel(a)vger.kernel.org --- fs/smb/client/cifssmb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 645831708e1b..1871d2c1a8e0 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -1395,7 +1395,7 @@ cifs_readv_callback(struct mid_q_entry *mid) } else { size_t trans = rdata->subreq.transferred + rdata->got_bytes; if (trans < rdata->subreq.len && - rdata->subreq.start + trans == ictx->remote_i_size) { + rdata->subreq.start + trans >= ictx->remote_i_size) { rdata->result = 0; __set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags); } else if (rdata->got_bytes > 0) {

3 days, 20 hours

4
8
0 0

Performance regressions introduced via Revert "cpuidle: menu: Avoid discarding useful information" on 5.15 LTS

by Harshvardhan Jha

Hi there, While running performance benchmarks for the 5.15.196 LTS tags , it was observed that several regressions across different benchmarks is being introduced when compared to the previous 5.15.193 kernel tag. Running an automated bisect on both of them narrowed down the culprit commit to: - 5666bcc3c00f7 Revert "cpuidle: menu: Avoid discarding useful information" for 5.15 Regressions on 5.15.196 include: -9.3% : Phoronix pts/sqlite using 2 processes on OnPrem X6-2 -6.3% : Phoronix system/sqlite on OnPrem X6-2 -18% : rds-stress -M 1 (readonly rdma-mode) metrics with 1 depth & 1 thread & 1M buffer size on OnPrem X6-2 -4 -> -8% : rds-stress -M 2 (writeonly rdma-mode) metrics with 1 depth & 1 thread & 1M buffer size on OnPrem X6-2 Up to -30% : Some Netpipe metrics on OnPrem X5-2 The culprit commits' messages mention that these reverts were done due to performance regressions introduced in Intel Jasper Lake systems but this revert is causing issues in other systems unfortunately. I wanted to know the maintainers' opinion on how we should proceed in order to fix this. If we reapply it'll bring back the previous regressions on Jasper Lake systems and if we don't revert it then it's stuck with current regressions. If this problem has been reported before and a fix is in the works then please let me know I shall follow developments to that mail thread. Thanks & Regards, Harshvardhan

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