linux/mm
Sasha Levin f0774d884b mm: shmem: check for mapping owner before dereferencing
mapping->host can be NULL and shouldn't be dereferenced before being checked.

[ 1295.741844] GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] SMP KASAN
[ 1295.746387] Dumping ftrace buffer:
[ 1295.748217]    (ftrace buffer empty)
[ 1295.749527] Modules linked in:
[ 1295.750268] CPU: 62 PID: 23410 Comm: trinity-c70 Not tainted 3.19.0-next-20150219-sasha-00045-g9130270f #1939
[ 1295.750268] task: ffff8803a49db000 ti: ffff8803a4dc8000 task.ti: ffff8803a4dc8000
[ 1295.750268] RIP: shmem_mapping (mm/shmem.c:1458)
[ 1295.750268] RSP: 0000:ffff8803a4dcfbf8  EFLAGS: 00010206
[ 1295.750268] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 00000000000f2804
[ 1295.750268] RDX: 0000000000000005 RSI: 0400000000000794 RDI: 0000000000000028
[ 1295.750268] RBP: ffff8803a4dcfc08 R08: 0000000000000000 R09: 00000000031de000
[ 1295.750268] R10: dffffc0000000000 R11: 00000000031c1000 R12: 0400000000000794
[ 1295.750268] R13: 00000000031c2000 R14: 00000000031de000 R15: ffff880e3bdc1000
[ 1295.750268] FS:  00007f8703c7e700(0000) GS:ffff881164800000(0000) knlGS:0000000000000000
[ 1295.750268] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1295.750268] CR2: 0000000004e58000 CR3: 00000003a9f3c000 CR4: 00000000000007a0
[ 1295.750268] DR0: ffffffff81000000 DR1: 0000009494949494 DR2: 0000000000000000
[ 1295.750268] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000d0602
[ 1295.750268] Stack:
[ 1295.750268]  ffff8803a4dcfec8 ffffffffbb1dc770 ffff8803a4dcfc38 ffffffffad6f230b
[ 1295.750268]  ffffffffad6f2b0d 0000014100000000 ffff88001e17c08b ffff880d9453fe08
[ 1295.750268]  ffff8803a4dcfd18 ffffffffad6f2ce2 ffff8803a49dbcd8 ffff8803a49dbce0
[ 1295.750268] Call Trace:
[ 1295.750268] mincore_page (mm/mincore.c:61)
[ 1295.750268] ? mincore_pte_range (include/linux/spinlock.h:312 mm/mincore.c:131)
[ 1295.750268] mincore_pte_range (mm/mincore.c:151)
[ 1295.750268] ? mincore_unmapped_range (mm/mincore.c:113)
[ 1295.750268] __walk_page_range (mm/pagewalk.c:51 mm/pagewalk.c:90 mm/pagewalk.c:116 mm/pagewalk.c:204)
[ 1295.750268] walk_page_range (mm/pagewalk.c:275)
[ 1295.750268] SyS_mincore (mm/mincore.c:191 mm/mincore.c:253 mm/mincore.c:220)
[ 1295.750268] ? mincore_pte_range (mm/mincore.c:220)
[ 1295.750268] ? mincore_unmapped_range (mm/mincore.c:113)
[ 1295.750268] ? __mincore_unmapped_range (mm/mincore.c:105)
[ 1295.750268] ? ptlock_free (mm/mincore.c:24)
[ 1295.750268] ? syscall_trace_enter (arch/x86/kernel/ptrace.c:1610)
[ 1295.750268] ia32_do_call (arch/x86/ia32/ia32entry.S:446)
[ 1295.750268] Code: e5 48 c1 ea 03 53 48 89 fb 48 83 ec 08 80 3c 02 00 75 4f 48 b8 00 00 00 00 00 fc ff df 48 8b 1b 48 8d 7b 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 3f 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 28 48

All code
========
   0:	e5 48                	in     $0x48,%eax
   2:	c1 ea 03             	shr    $0x3,%edx
   5:	53                   	push   %rbx
   6:	48 89 fb             	mov    %rdi,%rbx
   9:	48 83 ec 08          	sub    $0x8,%rsp
   d:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  11:	75 4f                	jne    0x62
  13:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1a:	fc ff df
  1d:	48 8b 1b             	mov    (%rbx),%rbx
  20:	48 8d 7b 28          	lea    0x28(%rbx),%rdi
  24:	48 89 fa             	mov    %rdi,%rdx
  27:	48 c1 ea 03          	shr    $0x3,%rdx
  2b:*	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)		<-- trapping instruction
  2f:	75 3f                	jne    0x70
  31:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  38:	fc ff df
  3b:	48 8b 5b 28          	mov    0x28(%rbx),%rbx
  3f:	48                   	rex.W
	...

Code starting with the faulting instruction
===========================================
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	75 3f                	jne    0x45
   6:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   d:	fc ff df
  10:	48 8b 5b 28          	mov    0x28(%rbx),%rbx
  14:	48                   	rex.W
	...
[ 1295.750268] RIP shmem_mapping (mm/shmem.c:1458)
[ 1295.750268]  RSP <ffff8803a4dcfbf8>

Fixes: 97b713ba3e ("fs: kill BDI_CAP_SWAP_BACKED")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-23 10:00:11 -08:00
..
kasan kasan: enable instrumentation of global variables 2015-02-13 21:21:42 -08:00
backing-dev.c Merge branch 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-17 16:12:34 -08:00
balloon_compaction.c mm/balloon_compaction: fix deflation when compaction is disabled 2014-10-29 16:33:15 -07:00
bootmem.c mem-hotplug: reset node managed pages when hot-adding a new pgdat 2014-11-13 16:17:06 -08:00
cleancache.c mm: fix cleancache debugfs directory path 2015-01-20 14:08:31 +01:00
cma.c mm: cma: fix totalcma_pages to include DT defined CMA regions 2015-02-11 17:06:03 -08:00
compaction.c mm: page_alloc: add kasan hooks on alloc and free paths 2015-02-13 21:21:41 -08:00
debug-pagealloc.c mm/debug-pagealloc: make debug-pagealloc boottime configurable 2014-12-13 12:42:48 -08:00
debug.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
dmapool.c mm/dmapool.c: fixed a brace coding style issue 2014-10-09 22:26:00 -04:00
early_ioremap.c
fadvise.c vfs: remove get_xip_mem 2015-02-16 17:56:03 -08:00
failslab.c
filemap.c dax,ext2: replace XIP read and write with DAX I/O 2015-02-16 17:56:03 -08:00
frontswap.c mm/frontswap.c: fix the condition in BUG_ON 2014-12-10 17:41:08 -08:00
gup.c Tighten rules for ACCESS_ONCE 2015-02-14 10:54:28 -08:00
highmem.c
huge_memory.c mm: numa: avoid unnecessary TLB flushes when setting NUMA hinting entries 2015-02-12 18:54:08 -08:00
hugetlb_cgroup.c mm: page_counter: pull "-1" handling out of page_counter_memparse() 2015-02-11 17:06:02 -08:00
hugetlb.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
hwpoison-inject.c
init-mm.c
internal.h mm/internal.h: don't split printk call in two 2015-02-12 18:54:10 -08:00
interval_tree.c mm: replace vma->sharead.linear with vma->shared 2015-02-10 14:30:31 -08:00
iov_iter.c new helper: iov_iter_bvec() 2015-01-29 00:13:11 -05:00
Kconfig Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2015-02-19 10:36:45 -08:00
Kconfig.debug mm/debug_pagealloc: remove obsolete Kconfig options 2015-01-08 15:10:52 -08:00
kmemcheck.c mm/slab_common: move kmem_cache definition to internal header 2014-10-09 22:25:50 -04:00
kmemleak-test.c
kmemleak.c kmemleak: disable kasan instrumentation for kmemleak 2015-02-13 21:21:41 -08:00
ksm.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
list_lru.c memcg: reparent list_lrus and free kmemcg_id on css offline 2015-02-12 18:54:10 -08:00
maccess.c
madvise.c vfs: remove get_xip_mem 2015-02-16 17:56:03 -08:00
Makefile vfs: remove get_xip_mem 2015-02-16 17:56:03 -08:00
memblock.c mm/memblock.c: refactor functions to set/clear MEMBLOCK_HOTPLUG 2014-12-13 12:42:46 -08:00
memcontrol.c memcg: cleanup static keys decrement 2015-02-12 18:54:10 -08:00
memory_hotplug.c mm, memory_hotplug/failure: drain single zone pcplists 2014-12-10 17:41:05 -08:00
memory-failure.c mm: hwpoison: drop lru_add_drain_all() in __soft_offline_page() 2015-02-12 18:54:11 -08:00
memory.c mm: allow page fault handlers to perform the COW 2015-02-16 17:56:03 -08:00
mempolicy.c mm: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
mempool.c
migrate.c mm: convert p[te|md]_mknonnuma and remaining page table manipulations 2015-02-12 18:54:08 -08:00
mincore.c mincore: apply page table walker on do_mincore() 2015-02-11 17:06:06 -08:00
mlock.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:44:12 +02:00
mm_init.c mm/mm_init.c: mark mminit_loglevel __meminitdata 2015-02-12 18:54:11 -08:00
mmap.c mm/mmap.c: fix arithmetic overflow in __vm_enough_memory() 2015-02-11 17:06:07 -08:00
mmu_context.c
mmu_notifier.c mmu_notifier: add the callback for mmu_notifier_invalidate_range() 2014-11-13 13:46:09 +11:00
mmzone.c mm: microoptimize zonelist operations 2015-02-11 17:06:02 -08:00
mprotect.c mm: numa: avoid unnecessary TLB flushes when setting NUMA hinting entries 2015-02-12 18:54:08 -08:00
mremap.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
msync.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
nobootmem.c mem-hotplug: reset node managed pages when hot-adding a new pgdat 2014-11-13 16:17:06 -08:00
nommu.c Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block 2015-02-12 13:50:21 -08:00
oom_kill.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
page_alloc.c mm: page_alloc: add kasan hooks on alloc and free paths 2015-02-13 21:21:41 -08:00
page_counter.c mm: page_counter: pull "-1" handling out of page_counter_memparse() 2015-02-11 17:06:02 -08:00
page_ext.c mm/page_owner: keep track of page owners 2014-12-13 12:42:48 -08:00
page_io.c new helper: iov_iter_bvec() 2015-01-29 00:13:11 -05:00
page_isolation.c mm, page_isolation: drain single zone pcplists 2014-12-10 17:41:05 -08:00
page_owner.c mm/page_owner.c: remove unnecessary stack_trace field 2015-02-11 17:06:07 -08:00
page-writeback.c Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block 2015-02-12 13:50:21 -08:00
pagewalk.c mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) 2015-02-11 17:06:06 -08:00
percpu-km.c
percpu-vm.c
percpu.c percpu: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
pgtable-generic.c mm: convert p[te|md]_mknonnuma and remaining page table manipulations 2015-02-12 18:54:08 -08:00
process_vm_access.c mm: gup: use get_user_pages_unlocked 2015-02-11 17:06:05 -08:00
quicklist.c
readahead.c fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info 2015-01-20 14:03:04 -07:00
rmap.c mm: memcontrol: track move_lock state internally 2015-02-11 17:06:00 -08:00
shmem.c mm: shmem: check for mapping owner before dereferencing 2015-02-23 10:00:11 -08:00
slab_common.c mm: slub: add kernel address sanitizer support for slub allocator 2015-02-13 21:21:41 -08:00
slab.c slub: make dead caches discard free slabs immediately 2015-02-12 18:54:10 -08:00
slab.h slub: make dead caches discard free slabs immediately 2015-02-12 18:54:10 -08:00
slob.c slub: make dead caches discard free slabs immediately 2015-02-12 18:54:10 -08:00
slub.c mm: slub: add kernel address sanitizer support for slub allocator 2015-02-13 21:21:41 -08:00
sparse-vmemmap.c
sparse.c
swap_cgroup.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
swap_state.c fs: remove mapping->backing_dev_info 2015-01-20 14:03:05 -07:00
swap.c Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block 2015-02-12 13:50:21 -08:00
swapfile.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
truncate.c fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info 2015-01-20 14:03:04 -07:00
util.c mm/util: add kstrdup_const 2015-02-13 21:21:35 -08:00
vmacache.c mm,vmacache: count number of system-wide flushes 2014-12-13 12:42:48 -08:00
vmalloc.c mm: vmalloc: pass additional vm_flags to __vmalloc_node_range() 2015-02-13 21:21:42 -08:00
vmpressure.c mm/vmpressure.c: fix race in vmpressure_work_fn() 2014-12-02 17:32:07 -08:00
vmscan.c Merge branch 'akpm' (patches from Andrew) 2015-02-12 18:54:28 -08:00
vmstat.c vmstat: Reduce time interval to stat update on idle cpu 2015-02-11 17:06:07 -08:00
workingset.c list_lru: add helpers to isolate items 2015-02-12 18:54:10 -08:00
zbud.c mm/zpool: add name argument to create zpool 2015-02-12 18:54:12 -08:00
zpool.c mm/zpool: add name argument to create zpool 2015-02-12 18:54:12 -08:00
zsmalloc.c mm/zsmalloc: add statistics support 2015-02-12 18:54:12 -08:00
zswap.c mm/zpool: add name argument to create zpool 2015-02-12 18:54:12 -08:00