This is a note to let you know that I've just added the patch titled selinux: use __GFP_NOWARN with GFP_NOWAIT in the AVC to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selinux-use-__gfp_nowarn-with-gfp_nowait-in-the-avc.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b6c18ca8bfbc81e1e9b811969d1e4aa08c51dc0c Author: Minchan Kim <minchan@xxxxxxxxxx> Date: Wed Jun 9 09:37:17 2021 -0700 selinux: use __GFP_NOWARN with GFP_NOWAIT in the AVC [ Upstream commit 648f2c6100cfa18e7dfe43bc0b9c3b73560d623c ] In the field, we have seen lots of allocation failure from the call path below. 06-03 13:29:12.999 1010315 31557 31557 W Binder : 31542_2: page allocation failure: order:0, mode:0x800(GFP_NOWAIT), nodemask=(null),cpuset=background,mems_allowed=0 ... ... 06-03 13:29:12.999 1010315 31557 31557 W Call trace: 06-03 13:29:12.999 1010315 31557 31557 W : dump_backtrace.cfi_jt+0x0/0x8 06-03 13:29:12.999 1010315 31557 31557 W : dump_stack+0xc8/0x14c 06-03 13:29:12.999 1010315 31557 31557 W : warn_alloc+0x158/0x1c8 06-03 13:29:12.999 1010315 31557 31557 W : __alloc_pages_slowpath+0x9d8/0xb80 06-03 13:29:12.999 1010315 31557 31557 W : __alloc_pages_nodemask+0x1c4/0x430 06-03 13:29:12.999 1010315 31557 31557 W : allocate_slab+0xb4/0x390 06-03 13:29:12.999 1010315 31557 31557 W : ___slab_alloc+0x12c/0x3a4 06-03 13:29:12.999 1010315 31557 31557 W : kmem_cache_alloc+0x358/0x5e4 06-03 13:29:12.999 1010315 31557 31557 W : avc_alloc_node+0x30/0x184 06-03 13:29:12.999 1010315 31557 31557 W : avc_update_node+0x54/0x4f0 06-03 13:29:12.999 1010315 31557 31557 W : avc_has_extended_perms+0x1a4/0x460 06-03 13:29:12.999 1010315 31557 31557 W : selinux_file_ioctl+0x320/0x3d0 06-03 13:29:12.999 1010315 31557 31557 W : __arm64_sys_ioctl+0xec/0x1fc 06-03 13:29:12.999 1010315 31557 31557 W : el0_svc_common+0xc0/0x24c 06-03 13:29:12.999 1010315 31557 31557 W : el0_svc+0x28/0x88 06-03 13:29:12.999 1010315 31557 31557 W : el0_sync_handler+0x8c/0xf0 06-03 13:29:12.999 1010315 31557 31557 W : el0_sync+0x1a4/0x1c0 .. .. 06-03 13:29:12.999 1010315 31557 31557 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010315 31557 31557 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010315 31557 31557 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 10230 30892 30892 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 10230 30892 30892 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 10230 30892 30892 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 10230 30892 30892 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 10230 30892 30892 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 Based on [1], selinux is tolerate for failure of memory allocation. Then, use __GFP_NOWARN together. [1] 476accbe2f6e ("selinux: use GFP_NOWAIT in the AVC kmem_caches") Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> [PM: subj fix, line wraps, normalized commit refs] Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 23f387b30ece..af70b4210f99 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -346,26 +346,27 @@ static struct avc_xperms_decision_node struct avc_xperms_decision_node *xpd_node; struct extended_perms_decision *xpd; - xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, GFP_NOWAIT); + xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, + GFP_NOWAIT | __GFP_NOWARN); if (!xpd_node) return NULL; xpd = &xpd_node->xpd; if (which & XPERMS_ALLOWED) { xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep, - GFP_NOWAIT); + GFP_NOWAIT | __GFP_NOWARN); if (!xpd->allowed) goto error; } if (which & XPERMS_AUDITALLOW) { xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep, - GFP_NOWAIT); + GFP_NOWAIT | __GFP_NOWARN); if (!xpd->auditallow) goto error; } if (which & XPERMS_DONTAUDIT) { xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep, - GFP_NOWAIT); + GFP_NOWAIT | __GFP_NOWARN); if (!xpd->dontaudit) goto error; } @@ -393,7 +394,7 @@ static struct avc_xperms_node *avc_xperms_alloc(void) { struct avc_xperms_node *xp_node; - xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT); + xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT | __GFP_NOWARN); if (!xp_node) return xp_node; INIT_LIST_HEAD(&xp_node->xpd_head); @@ -546,7 +547,7 @@ static struct avc_node *avc_alloc_node(void) { struct avc_node *node; - node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT); + node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT | __GFP_NOWARN); if (!node) goto out;