June 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f122dfe4476890d60b8c679128cd2259ec96a24c Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Wed, 2 Feb 2022 00:49:43 +0000 Subject: [PATCH] KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits Use the recently introduced __try_cmpxchg_user() to update guest PTE A/D bits instead of mapping the PTE into kernel address space. The VM_PFNMAP path is broken as it assumes that vm_pgoff is the base pfn of the mapped VMA range, which is conceptually wrong as vm_pgoff is the offset relative to the file and has nothing to do with the pfn. The horrific hack worked for the original use case (backing guest memory with /dev/mem), but leads to accessing "random" pfns for pretty much any other VM_PFNMAP case. Fixes: bd53cb35a3e9 ("X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs") Debugged-by: Tadeusz Struk <tadeusz.struk(a)linaro.org> Tested-by: Tadeusz Struk <tadeusz.struk(a)linaro.org> Reported-by: syzbot+6cde2282daa792c49ab8(a)syzkaller.appspotmail.com Cc: stable(a)vger.kernel.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> Message-Id: <20220202004945.2540433-4-seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 1dad8f3f2bb0..7d4377f1ef2a 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -144,42 +144,6 @@ static bool FNAME(is_rsvd_bits_set)(struct kvm_mmu *mmu, u64 gpte, int level) FNAME(is_bad_mt_xwr)(&mmu->guest_rsvd_check, gpte); } -static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, - pt_element_t __user *ptep_user, unsigned index, - pt_element_t orig_pte, pt_element_t new_pte) -{ - signed char r; - - if (!user_access_begin(ptep_user, sizeof(pt_element_t))) - return -EFAULT; - -#ifdef CMPXCHG - asm volatile("1:" LOCK_PREFIX CMPXCHG " %[new], %[ptr]\n" - "setnz %b[r]\n" - "2:" - _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %k[r]) - : [ptr] "+m" (*ptep_user), - [old] "+a" (orig_pte), - [r] "=q" (r) - : [new] "r" (new_pte) - : "memory"); -#else - asm volatile("1:" LOCK_PREFIX "cmpxchg8b %[ptr]\n" - "setnz %b[r]\n" - "2:" - _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %k[r]) - : [ptr] "+m" (*ptep_user), - [old] "+A" (orig_pte), - [r] "=q" (r) - : [new_lo] "b" ((u32)new_pte), - [new_hi] "c" ((u32)(new_pte >> 32)) - : "memory"); -#endif - - user_access_end(); - return r; -} - static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, u64 *spte, u64 gpte) @@ -278,7 +242,7 @@ static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu, if (unlikely(!walker->pte_writable[level - 1])) continue; - ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, orig_pte, pte); + ret = __try_cmpxchg_user(ptep_user, &orig_pte, pte, fault); if (ret) return ret;

3 years, 6 months

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FAILED: patch "[PATCH] netfilter: nf_tables: hold mutex on netns pre_exit path" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 3923b1e4406680d57da7e873da77b1683035d83f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso <pablo(a)netfilter.org> Date: Mon, 30 May 2022 18:24:05 +0200 Subject: [PATCH] netfilter: nf_tables: hold mutex on netns pre_exit path clean_net() runs in workqueue while walking over the lists, grab mutex. Fixes: 767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns") Signed-off-by: Pablo Neira Ayuso <pablo(a)netfilter.org> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index dcefb5f36b3a..f77414e13de1 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -9896,7 +9896,11 @@ static int __net_init nf_tables_init_net(struct net *net) static void __net_exit nf_tables_pre_exit_net(struct net *net) { + struct nftables_pernet *nft_net = nft_pernet(net); + + mutex_lock(&nft_net->commit_mutex); __nft_release_hooks(net); + mutex_unlock(&nft_net->commit_mutex); } static void __net_exit nf_tables_exit_net(struct net *net)

3 years, 6 months

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FAILED: patch "[PATCH] netfilter: nf_tables: hold mutex on netns pre_exit path" 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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 3923b1e4406680d57da7e873da77b1683035d83f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso <pablo(a)netfilter.org> Date: Mon, 30 May 2022 18:24:05 +0200 Subject: [PATCH] netfilter: nf_tables: hold mutex on netns pre_exit path clean_net() runs in workqueue while walking over the lists, grab mutex. Fixes: 767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns") Signed-off-by: Pablo Neira Ayuso <pablo(a)netfilter.org> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index dcefb5f36b3a..f77414e13de1 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -9896,7 +9896,11 @@ static int __net_init nf_tables_init_net(struct net *net) static void __net_exit nf_tables_pre_exit_net(struct net *net) { + struct nftables_pernet *nft_net = nft_pernet(net); + + mutex_lock(&nft_net->commit_mutex); __nft_release_hooks(net); + mutex_unlock(&nft_net->commit_mutex); } static void __net_exit nf_tables_exit_net(struct net *net)

3 years, 6 months

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FAILED: patch "[PATCH] netfilter: nf_tables: double hook unregistration in netns" 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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f9a43007d3f7ba76d5e7f9421094f00f2ef202f8 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso <pablo(a)netfilter.org> Date: Mon, 30 May 2022 18:24:06 +0200 Subject: [PATCH] netfilter: nf_tables: double hook unregistration in netns path __nft_release_hooks() is called from pre_netns exit path which unregisters the hooks, then the NETDEV_UNREGISTER event is triggered which unregisters the hooks again. [ 565.221461] WARNING: CPU: 18 PID: 193 at net/netfilter/core.c:495 __nf_unregister_net_hook+0x247/0x270 [...] [ 565.246890] CPU: 18 PID: 193 Comm: kworker/u64:1 Tainted: G E 5.18.0-rc7+ #27 [ 565.253682] Workqueue: netns cleanup_net [ 565.257059] RIP: 0010:__nf_unregister_net_hook+0x247/0x270 [...] [ 565.297120] Call Trace: [ 565.300900] <TASK> [ 565.304683] nf_tables_flowtable_event+0x16a/0x220 [nf_tables] [ 565.308518] raw_notifier_call_chain+0x63/0x80 [ 565.312386] unregister_netdevice_many+0x54f/0xb50 Unregister and destroy netdev hook from netns pre_exit via kfree_rcu so the NETDEV_UNREGISTER path see unregistered hooks. Fixes: 767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns") Signed-off-by: Pablo Neira Ayuso <pablo(a)netfilter.org> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index f77414e13de1..746be13438ef 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -222,12 +222,18 @@ static int nft_netdev_register_hooks(struct net *net, } static void nft_netdev_unregister_hooks(struct net *net, - struct list_head *hook_list) + struct list_head *hook_list, + bool release_netdev) { - struct nft_hook *hook; + struct nft_hook *hook, *next; - list_for_each_entry(hook, hook_list, list) + list_for_each_entry_safe(hook, next, hook_list, list) { nf_unregister_net_hook(net, &hook->ops); + if (release_netdev) { + list_del(&hook->list); + kfree_rcu(hook, rcu); + } + } } static int nf_tables_register_hook(struct net *net, @@ -253,9 +259,10 @@ static int nf_tables_register_hook(struct net *net, return nf_register_net_hook(net, &basechain->ops); } -static void nf_tables_unregister_hook(struct net *net, - const struct nft_table *table, - struct nft_chain *chain) +static void __nf_tables_unregister_hook(struct net *net, + const struct nft_table *table, + struct nft_chain *chain, + bool release_netdev) { struct nft_base_chain *basechain; const struct nf_hook_ops *ops; @@ -270,11 +277,19 @@ static void nf_tables_unregister_hook(struct net *net, return basechain->type->ops_unregister(net, ops); if (nft_base_chain_netdev(table->family, basechain->ops.hooknum)) - nft_netdev_unregister_hooks(net, &basechain->hook_list); + nft_netdev_unregister_hooks(net, &basechain->hook_list, + release_netdev); else nf_unregister_net_hook(net, &basechain->ops); } +static void nf_tables_unregister_hook(struct net *net, + const struct nft_table *table, + struct nft_chain *chain) +{ + return __nf_tables_unregister_hook(net, table, chain, false); +} + static void nft_trans_commit_list_add_tail(struct net *net, struct nft_trans *trans) { struct nftables_pernet *nft_net = nft_pernet(net); @@ -7307,13 +7322,25 @@ static void nft_unregister_flowtable_hook(struct net *net, FLOW_BLOCK_UNBIND); } -static void nft_unregister_flowtable_net_hooks(struct net *net, - struct list_head *hook_list) +static void __nft_unregister_flowtable_net_hooks(struct net *net, + struct list_head *hook_list, + bool release_netdev) { - struct nft_hook *hook; + struct nft_hook *hook, *next; - list_for_each_entry(hook, hook_list, list) + list_for_each_entry_safe(hook, next, hook_list, list) { nf_unregister_net_hook(net, &hook->ops); + if (release_netdev) { + list_del(&hook->list); + kfree_rcu(hook); + } + } +} + +static void nft_unregister_flowtable_net_hooks(struct net *net, + struct list_head *hook_list) +{ + __nft_unregister_flowtable_net_hooks(net, hook_list, false); } static int nft_register_flowtable_net_hooks(struct net *net, @@ -9755,9 +9782,10 @@ static void __nft_release_hook(struct net *net, struct nft_table *table) struct nft_chain *chain; list_for_each_entry(chain, &table->chains, list) - nf_tables_unregister_hook(net, table, chain); + __nf_tables_unregister_hook(net, table, chain, true); list_for_each_entry(flowtable, &table->flowtables, list) - nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list); + __nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list, + true); } static void __nft_release_hooks(struct net *net)

3 years, 6 months

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[PATCH v3] xen/gntdev: Avoid blocking in unmap_grant_pages()

by Demi Marie Obenour

unmap_grant_pages() currently waits for the pages to no longer be used. In https://github.com/QubesOS/qubes-issues/issues/7481, this lead to a deadlock against i915: i915 was waiting for gntdev's MMU notifier to finish, while gntdev was waiting for i915 to free its pages. I also believe this is responsible for various deadlocks I have experienced in the past. Avoid these problems by making unmap_grant_pages async. This requires making it return void, as any errors will not be available when the function returns. Fortunately, the only use of the return value is a WARN_ON(), which can be replaced by a WARN_ON when the error is detected. Additionally, a failed call will not prevent further calls from being made, but this is harmless. Because unmap_grant_pages is now async, the grant handle will be sent to INVALID_GRANT_HANDLE too late to prevent multiple unmaps of the same handle. Instead, a separate bool array is allocated for this purpose. This wastes memory, but stuffing this information in padding bytes is too fragile. Furthermore, it is necessary to grab a reference to the map before making the asynchronous call, and release the reference when the call returns. It is also necessary to guard against reentrancy in gntdev_map_put(), and to handle the case where userspace tries to map a mapping whose contents have not all been freed yet. Fixes: 745282256c75 ("xen/gntdev: safely unmap grants in case they are still in use") Cc: stable(a)vger.kernel.org Signed-off-by: Demi Marie Obenour <demi(a)invisiblethingslab.com> --- drivers/xen/gntdev-common.h | 7 ++ drivers/xen/gntdev.c | 153 ++++++++++++++++++++++++------------ 2 files changed, 109 insertions(+), 51 deletions(-) diff --git a/drivers/xen/gntdev-common.h b/drivers/xen/gntdev-common.h index 20d7d059dadb..15c2e3afcc2b 100644 --- a/drivers/xen/gntdev-common.h +++ b/drivers/xen/gntdev-common.h @@ -16,6 +16,7 @@ #include <linux/mmu_notifier.h> #include <linux/types.h> #include <xen/interface/event_channel.h> +#include <xen/grant_table.h> struct gntdev_dmabuf_priv; @@ -56,6 +57,7 @@ struct gntdev_grant_map { struct gnttab_unmap_grant_ref *unmap_ops; struct gnttab_map_grant_ref *kmap_ops; struct gnttab_unmap_grant_ref *kunmap_ops; + bool *being_removed; struct page **pages; unsigned long pages_vm_start; @@ -73,6 +75,11 @@ struct gntdev_grant_map { /* Needed to avoid allocation in gnttab_dma_free_pages(). */ xen_pfn_t *frames; #endif + + /* Number of live grants */ + atomic_long_t live_grants; + /* Needed to avoid allocation in __unmap_grant_pages */ + struct gntab_unmap_queue_data unmap_data; }; struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 59ffea800079..e8b83ea1eacd 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -35,6 +35,7 @@ #include <linux/slab.h> #include <linux/highmem.h> #include <linux/refcount.h> +#include <linux/workqueue.h> #include <xen/xen.h> #include <xen/grant_table.h> @@ -60,10 +61,11 @@ module_param(limit, uint, 0644); MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by one mapping request"); +/* True in PV mode, false otherwise */ static int use_ptemod; -static int unmap_grant_pages(struct gntdev_grant_map *map, - int offset, int pages); +static void unmap_grant_pages(struct gntdev_grant_map *map, + int offset, int pages); static struct miscdevice gntdev_miscdev; @@ -120,6 +122,7 @@ static void gntdev_free_map(struct gntdev_grant_map *map) kvfree(map->unmap_ops); kvfree(map->kmap_ops); kvfree(map->kunmap_ops); + kvfree(map->being_removed); kfree(map); } @@ -140,10 +143,13 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, add->unmap_ops = kvmalloc_array(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); add->pages = kvcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); + add->being_removed = + kvcalloc(count, sizeof(add->being_removed[0]), GFP_KERNEL); if (NULL == add->grants || NULL == add->map_ops || NULL == add->unmap_ops || - NULL == add->pages) + NULL == add->pages || + NULL == add->being_removed) goto err; if (use_ptemod) { add->kmap_ops = kvmalloc_array(count, sizeof(add->kmap_ops[0]), @@ -250,9 +256,34 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map) if (!refcount_dec_and_test(&map->users)) return; - if (map->pages && !use_ptemod) + if (map->pages && !use_ptemod) { + /* + * Increment the reference count. This ensures that the + * subsequent call to unmap_grant_pages() will not wind up + * re-entering itself. It *can* wind up calling + * gntdev_put_map() recursively, but such calls will be with a + * nonzero reference count, so they will return before this code + * is reached. The recursion depth is thus limited to 1. + */ + refcount_inc(&map->users); + + /* + * Unmap the grants. This may or may not be asynchronous, so it + * is possible that the reference count is 1 on return, but it + * could also be greater than 1. + */ unmap_grant_pages(map, 0, map->count); + /* Check if the memory now needs to be freed */ + if (!refcount_dec_and_test(&map->users)) + return; + + /* + * All pages have been returned to the hypervisor, so free the + * map. FIXME: this is far too complex. + */ + } + if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { notify_remote_via_evtchn(map->notify.event); evtchn_put(map->notify.event); @@ -283,6 +314,7 @@ static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data) int gntdev_map_grant_pages(struct gntdev_grant_map *map) { + size_t alloced = 0; int i, err = 0; if (!use_ptemod) { @@ -331,97 +363,114 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map) map->count); for (i = 0; i < map->count; i++) { - if (map->map_ops[i].status == GNTST_okay) + if (map->map_ops[i].status == GNTST_okay) { map->unmap_ops[i].handle = map->map_ops[i].handle; - else if (!err) + if (!use_ptemod) + alloced++; + } else if (!err) err = -EINVAL; if (map->flags & GNTMAP_device_map) map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr; if (use_ptemod) { - if (map->kmap_ops[i].status == GNTST_okay) + if (map->kmap_ops[i].status == GNTST_okay) { + if (map->map_ops[i].status == GNTST_okay) + alloced++; map->kunmap_ops[i].handle = map->kmap_ops[i].handle; - else if (!err) + } else if (!err) { + /* FIXME: should this be a WARN()? */ err = -EINVAL; + } } } + atomic_long_add(alloced, &map->live_grants); return err; } -static int __unmap_grant_pages(struct gntdev_grant_map *map, int offset, - int pages) +static void __unmap_grant_pages_done(int result, + struct gntab_unmap_queue_data *data) { - int i, err = 0; - struct gntab_unmap_queue_data unmap_data; - - if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { - int pgno = (map->notify.addr >> PAGE_SHIFT); - if (pgno >= offset && pgno < offset + pages) { - /* No need for kmap, pages are in lowmem */ - uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); - tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; - map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; - } - } - - unmap_data.unmap_ops = map->unmap_ops + offset; - unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL; - unmap_data.pages = map->pages + offset; - unmap_data.count = pages; - - err = gnttab_unmap_refs_sync(&unmap_data); - if (err) - return err; + unsigned int i; + struct gntdev_grant_map *map = data->data; + unsigned int offset = data->unmap_ops - map->unmap_ops; + atomic_long_sub(data->count, &map->live_grants); - for (i = 0; i < pages; i++) { - if (map->unmap_ops[offset+i].status) - err = -EINVAL; + for (i = 0; i < data->count; i++) { + WARN_ON(map->unmap_ops[offset+i].status); pr_debug("unmap handle=%d st=%d\n", map->unmap_ops[offset+i].handle, map->unmap_ops[offset+i].status); map->unmap_ops[offset+i].handle = INVALID_GRANT_HANDLE; if (use_ptemod) { - if (map->kunmap_ops[offset+i].status) - err = -EINVAL; + WARN_ON(map->kunmap_ops[offset+i].status); pr_debug("kunmap handle=%u st=%d\n", map->kunmap_ops[offset+i].handle, map->kunmap_ops[offset+i].status); map->kunmap_ops[offset+i].handle = INVALID_GRANT_HANDLE; } } - return err; + + /* Release reference taken by __unmap_grant_pages */ + gntdev_put_map(NULL, map); } -static int unmap_grant_pages(struct gntdev_grant_map *map, int offset, - int pages) +static void __unmap_grant_pages(struct gntdev_grant_map *map, int offset, + int pages) { - int range, err = 0; + if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { + int pgno = (map->notify.addr >> PAGE_SHIFT); + + if (pgno >= offset && pgno < offset + pages) { + /* No need for kmap, pages are in lowmem */ + uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); + + tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; + map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; + } + } + + map->unmap_data.unmap_ops = map->unmap_ops + offset; + map->unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL; + map->unmap_data.pages = map->pages + offset; + map->unmap_data.count = pages; + map->unmap_data.done = __unmap_grant_pages_done; + map->unmap_data.data = map; + refcount_inc(&map->users); /* to keep map alive during async call below */ + + gnttab_unmap_refs_async(&map->unmap_data); +} + +static void unmap_grant_pages(struct gntdev_grant_map *map, int offset, + int pages) +{ + int range; + + if (atomic_long_read(&map->live_grants) == 0) + return; /* Nothing to do */ pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); /* It is possible the requested range will have a "hole" where we * already unmapped some of the grants. Only unmap valid ranges. */ - while (pages && !err) { - while (pages && - map->unmap_ops[offset].handle == INVALID_GRANT_HANDLE) { + while (pages) { + while (pages && map->being_removed[offset]) { offset++; pages--; } range = 0; while (range < pages) { - if (map->unmap_ops[offset + range].handle == - INVALID_GRANT_HANDLE) + if (map->being_removed[offset + range]) break; + map->being_removed[offset + range] = true; range++; } - err = __unmap_grant_pages(map, offset, range); + if (range) + __unmap_grant_pages(map, offset, range); offset += range; pages -= range; } - - return err; } /* ------------------------------------------------------------------ */ @@ -473,7 +522,6 @@ static bool gntdev_invalidate(struct mmu_interval_notifier *mn, struct gntdev_grant_map *map = container_of(mn, struct gntdev_grant_map, notifier); unsigned long mstart, mend; - int err; if (!mmu_notifier_range_blockable(range)) return false; @@ -494,10 +542,9 @@ static bool gntdev_invalidate(struct mmu_interval_notifier *mn, map->index, map->count, map->vma->vm_start, map->vma->vm_end, range->start, range->end, mstart, mend); - err = unmap_grant_pages(map, + unmap_grant_pages(map, (mstart - map->vma->vm_start) >> PAGE_SHIFT, (mend - mstart) >> PAGE_SHIFT); - WARN_ON(err); return true; } @@ -985,6 +1032,10 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) goto unlock_out; if (use_ptemod && map->vma) goto unlock_out; + if (atomic_long_read(&map->live_grants)) { + err = -EAGAIN; + goto unlock_out; + } refcount_inc(&map->users); vma->vm_ops = &gntdev_vmops; -- Sincerely, Demi Marie Obenour (she/her/hers) Invisible Things Lab

3 years, 6 months

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FAILED: patch "[PATCH] netfilter: nf_tables: double hook unregistration in netns" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f9a43007d3f7ba76d5e7f9421094f00f2ef202f8 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso <pablo(a)netfilter.org> Date: Mon, 30 May 2022 18:24:06 +0200 Subject: [PATCH] netfilter: nf_tables: double hook unregistration in netns path __nft_release_hooks() is called from pre_netns exit path which unregisters the hooks, then the NETDEV_UNREGISTER event is triggered which unregisters the hooks again. [ 565.221461] WARNING: CPU: 18 PID: 193 at net/netfilter/core.c:495 __nf_unregister_net_hook+0x247/0x270 [...] [ 565.246890] CPU: 18 PID: 193 Comm: kworker/u64:1 Tainted: G E 5.18.0-rc7+ #27 [ 565.253682] Workqueue: netns cleanup_net [ 565.257059] RIP: 0010:__nf_unregister_net_hook+0x247/0x270 [...] [ 565.297120] Call Trace: [ 565.300900] <TASK> [ 565.304683] nf_tables_flowtable_event+0x16a/0x220 [nf_tables] [ 565.308518] raw_notifier_call_chain+0x63/0x80 [ 565.312386] unregister_netdevice_many+0x54f/0xb50 Unregister and destroy netdev hook from netns pre_exit via kfree_rcu so the NETDEV_UNREGISTER path see unregistered hooks. Fixes: 767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns") Signed-off-by: Pablo Neira Ayuso <pablo(a)netfilter.org> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index f77414e13de1..746be13438ef 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -222,12 +222,18 @@ static int nft_netdev_register_hooks(struct net *net, } static void nft_netdev_unregister_hooks(struct net *net, - struct list_head *hook_list) + struct list_head *hook_list, + bool release_netdev) { - struct nft_hook *hook; + struct nft_hook *hook, *next; - list_for_each_entry(hook, hook_list, list) + list_for_each_entry_safe(hook, next, hook_list, list) { nf_unregister_net_hook(net, &hook->ops); + if (release_netdev) { + list_del(&hook->list); + kfree_rcu(hook, rcu); + } + } } static int nf_tables_register_hook(struct net *net, @@ -253,9 +259,10 @@ static int nf_tables_register_hook(struct net *net, return nf_register_net_hook(net, &basechain->ops); } -static void nf_tables_unregister_hook(struct net *net, - const struct nft_table *table, - struct nft_chain *chain) +static void __nf_tables_unregister_hook(struct net *net, + const struct nft_table *table, + struct nft_chain *chain, + bool release_netdev) { struct nft_base_chain *basechain; const struct nf_hook_ops *ops; @@ -270,11 +277,19 @@ static void nf_tables_unregister_hook(struct net *net, return basechain->type->ops_unregister(net, ops); if (nft_base_chain_netdev(table->family, basechain->ops.hooknum)) - nft_netdev_unregister_hooks(net, &basechain->hook_list); + nft_netdev_unregister_hooks(net, &basechain->hook_list, + release_netdev); else nf_unregister_net_hook(net, &basechain->ops); } +static void nf_tables_unregister_hook(struct net *net, + const struct nft_table *table, + struct nft_chain *chain) +{ + return __nf_tables_unregister_hook(net, table, chain, false); +} + static void nft_trans_commit_list_add_tail(struct net *net, struct nft_trans *trans) { struct nftables_pernet *nft_net = nft_pernet(net); @@ -7307,13 +7322,25 @@ static void nft_unregister_flowtable_hook(struct net *net, FLOW_BLOCK_UNBIND); } -static void nft_unregister_flowtable_net_hooks(struct net *net, - struct list_head *hook_list) +static void __nft_unregister_flowtable_net_hooks(struct net *net, + struct list_head *hook_list, + bool release_netdev) { - struct nft_hook *hook; + struct nft_hook *hook, *next; - list_for_each_entry(hook, hook_list, list) + list_for_each_entry_safe(hook, next, hook_list, list) { nf_unregister_net_hook(net, &hook->ops); + if (release_netdev) { + list_del(&hook->list); + kfree_rcu(hook); + } + } +} + +static void nft_unregister_flowtable_net_hooks(struct net *net, + struct list_head *hook_list) +{ + __nft_unregister_flowtable_net_hooks(net, hook_list, false); } static int nft_register_flowtable_net_hooks(struct net *net, @@ -9755,9 +9782,10 @@ static void __nft_release_hook(struct net *net, struct nft_table *table) struct nft_chain *chain; list_for_each_entry(chain, &table->chains, list) - nf_tables_unregister_hook(net, table, chain); + __nf_tables_unregister_hook(net, table, chain, true); list_for_each_entry(flowtable, &table->flowtables, list) - nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list); + __nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list, + true); } static void __nft_release_hooks(struct net *net)

3 years, 6 months

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FAILED: patch "[PATCH] exec: Force single empty string when argv is empty" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From dcd46d897adb70d63e025f175a00a89797d31a43 Mon Sep 17 00:00:00 2001 From: Kees Cook <keescook(a)chromium.org> Date: Mon, 31 Jan 2022 16:09:47 -0800 Subject: [PATCH] exec: Force single empty string when argv is empty Quoting[1] Ariadne Conill: "In several other operating systems, it is a hard requirement that the second argument to execve(2) be the name of a program, thus prohibiting a scenario where argc < 1. POSIX 2017 also recommends this behaviour, but it is not an explicit requirement[2]: The argument arg0 should point to a filename string that is associated with the process being started by one of the exec functions. ... Interestingly, Michael Kerrisk opened an issue about this in 2008[3], but there was no consensus to support fixing this issue then. Hopefully now that CVE-2021-4034 shows practical exploitative use[4] of this bug in a shellcode, we can reconsider. This issue is being tracked in the KSPP issue tracker[5]." While the initial code searches[6][7] turned up what appeared to be mostly corner case tests, trying to that just reject argv == NULL (or an immediately terminated pointer list) quickly started tripping[8] existing userspace programs. The next best approach is forcing a single empty string into argv and adjusting argc to match. The number of programs depending on argc == 0 seems a smaller set than those calling execve with a NULL argv. Account for the additional stack space in bprm_stack_limits(). Inject an empty string when argc == 0 (and set argc = 1). Warn about the case so userspace has some notice about the change: process './argc0' launched './argc0' with NULL argv: empty string added Additionally WARN() and reject NULL argv usage for kernel threads. [1] https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.or… [2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html [3] https://bugzilla.kernel.org/show_bug.cgi?id=8408 [4] https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt [5] https://github.com/KSPP/linux/issues/176 [6] https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+… [7] https://codesearch.debian.net/search?q=execlp%3F%5Cs*%5C%28%5B%5E%2C%5D%2B%… [8] https://lore.kernel.org/lkml/20220131144352.GE16385@xsang-OptiPlex-9020/ Reported-by: Ariadne Conill <ariadne(a)dereferenced.org> Reported-by: Michael Kerrisk <mtk.manpages(a)gmail.com> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: Christian Brauner <brauner(a)kernel.org> Cc: Rich Felker <dalias(a)libc.org> Cc: Eric Biederman <ebiederm(a)xmission.com> Cc: Alexander Viro <viro(a)zeniv.linux.org.uk> Cc: linux-fsdevel(a)vger.kernel.org Cc: stable(a)vger.kernel.org Signed-off-by: Kees Cook <keescook(a)chromium.org> Acked-by: Christian Brauner <brauner(a)kernel.org> Acked-by: Ariadne Conill <ariadne(a)dereferenced.org> Acked-by: Andy Lutomirski <luto(a)kernel.org> Link: https://lore.kernel.org/r/20220201000947.2453721-1-keescook@chromium.org diff --git a/fs/exec.c b/fs/exec.c index 79f2c9483302..40b1008fb0f7 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -495,8 +495,14 @@ static int bprm_stack_limits(struct linux_binprm *bprm) * the stack. They aren't stored until much later when we can't * signal to the parent that the child has run out of stack space. * Instead, calculate it here so it's possible to fail gracefully. + * + * In the case of argc = 0, make sure there is space for adding a + * empty string (which will bump argc to 1), to ensure confused + * userspace programs don't start processing from argv[1], thinking + * argc can never be 0, to keep them from walking envp by accident. + * See do_execveat_common(). */ - ptr_size = (bprm->argc + bprm->envc) * sizeof(void *); + ptr_size = (max(bprm->argc, 1) + bprm->envc) * sizeof(void *); if (limit <= ptr_size) return -E2BIG; limit -= ptr_size; @@ -1897,6 +1903,9 @@ static int do_execveat_common(int fd, struct filename *filename, } retval = count(argv, MAX_ARG_STRINGS); + if (retval == 0) + pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n", + current->comm, bprm->filename); if (retval < 0) goto out_free; bprm->argc = retval; @@ -1923,6 +1932,19 @@ static int do_execveat_common(int fd, struct filename *filename, if (retval < 0) goto out_free; + /* + * When argv is empty, add an empty string ("") as argv[0] to + * ensure confused userspace programs that start processing + * from argv[1] won't end up walking envp. See also + * bprm_stack_limits(). + */ + if (bprm->argc == 0) { + retval = copy_string_kernel("", bprm); + if (retval < 0) + goto out_free; + bprm->argc = 1; + } + retval = bprm_execve(bprm, fd, filename, flags); out_free: free_bprm(bprm); @@ -1951,6 +1973,8 @@ int kernel_execve(const char *kernel_filename, } retval = count_strings_kernel(argv); + if (WARN_ON_ONCE(retval == 0)) + retval = -EINVAL; if (retval < 0) goto out_free; bprm->argc = retval;

3 years, 6 months

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[PATCH 4.14 0/1] block-map: backport fix for CVE-2022-0494

by Dragos-Marian Panait

The following commit is needed to fix CVE-2022-0494: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… Haimin Zhang (1): block-map: add __GFP_ZERO flag for alloc_page in function bio_copy_kern block/bio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: 501eec4f9e138b958fc7438e7a745c0d6a7c68b3 -- 2.36.1

3 years, 6 months

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[PATCH] BACKPORT: drm/amdgpu/disply: set num_crtc earlier

by Ryan Lin

From: Alex Deucher <alexander.deucher(a)amd.com> To avoid a recently added warning: Bogus possible_crtcs: [ENCODER:65:TMDS-65] possible_crtcs=0xf (full crtc mask=0x7) WARNING: CPU: 3 PID: 439 at drivers/gpu/drm/drm_mode_config.c:617 drm_mode_config_validate+0x178/0x200 [drm] In this case the warning is harmless, but confusing to users. Fixes: 0df108237433 ("drm: Validate encoder->possible_crtcs") Bug: https://bugzilla.kernel.org/show_bug.cgi?id=209123 Reviewed-by: Daniel Vetter <daniel(a)ffwll.ch> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Cc: stable(a)vger.kernel.org Conflicts: drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c [Ryan Lin: Fixed the conflict, remove the non-main changed part of this patch] --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index fb918b7890ac..5ef88a2d2161 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -766,9 +766,6 @@ static int amdgpu_dm_init(struct amdgpu_device *adev) goto error; } - /* Update the actual used number of crtc */ - adev->mode_info.num_crtc = adev->dm.display_indexes_num; - /* TODO: Add_display_info? */ /* TODO use dynamic cursor width */ @@ -2448,6 +2445,10 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev) enum dc_connection_type new_connection_type = dc_connection_none; const struct dc_plane_cap *plane; + dm->display_indexes_num = dm->dc->caps.max_streams; + /* Update the actual used number of crtc */ + adev->mode_info.num_crtc = adev->dm.display_indexes_num; + link_cnt = dm->dc->caps.max_links; if (amdgpu_dm_mode_config_init(dm->adev)) { DRM_ERROR("DM: Failed to initialize mode config\n"); @@ -2509,8 +2510,6 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev) goto fail; } - dm->display_indexes_num = dm->dc->caps.max_streams; - /* loops over all connectors on the board */ for (i = 0; i < link_cnt; i++) { struct dc_link *link = NULL; -- 2.25.1

3 years, 6 months

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exfat: check if cluster num is valid

by Tadeusz Struk

Hi, Please apply upstream commit: 64ba4b15e5c0 ("exfat: check if cluster num is valid") to stable 5.18.y and 5.17.y Backports for 5.15.y and 5.10.y will follow soon. -- Thanks, Tadeusz

3 years, 6 months

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