linux/mm
Roman Gushchin 33d9490b27 mm: kmem: fix a NULL pointer dereference in obj_stock_flush_required()
commit 3b8abb3239 upstream.

KCSAN found an issue in obj_stock_flush_required():
stock->cached_objcg can be reset between the check and dereference:

==================================================================
BUG: KCSAN: data-race in drain_all_stock / drain_obj_stock

write to 0xffff888237c2a2f8 of 8 bytes by task 19625 on cpu 0:
 drain_obj_stock+0x408/0x4e0 mm/memcontrol.c:3306
 refill_obj_stock+0x9c/0x1e0 mm/memcontrol.c:3340
 obj_cgroup_uncharge+0xe/0x10 mm/memcontrol.c:3408
 memcg_slab_free_hook mm/slab.h:587 [inline]
 __cache_free mm/slab.c:3373 [inline]
 __do_kmem_cache_free mm/slab.c:3577 [inline]
 kmem_cache_free+0x105/0x280 mm/slab.c:3602
 __d_free fs/dcache.c:298 [inline]
 dentry_free fs/dcache.c:375 [inline]
 __dentry_kill+0x422/0x4a0 fs/dcache.c:621
 dentry_kill+0x8d/0x1e0
 dput+0x118/0x1f0 fs/dcache.c:913
 __fput+0x3bf/0x570 fs/file_table.c:329
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x123/0x160 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xcf/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888237c2a2f8 of 8 bytes by task 19632 on cpu 1:
 obj_stock_flush_required mm/memcontrol.c:3319 [inline]
 drain_all_stock+0x174/0x2a0 mm/memcontrol.c:2361
 try_charge_memcg+0x6d0/0xd10 mm/memcontrol.c:2703
 try_charge mm/memcontrol.c:2837 [inline]
 mem_cgroup_charge_skmem+0x51/0x140 mm/memcontrol.c:7290
 sock_reserve_memory+0xb1/0x390 net/core/sock.c:1025
 sk_setsockopt+0x800/0x1e70 net/core/sock.c:1525
 udp_lib_setsockopt+0x99/0x6c0 net/ipv4/udp.c:2692
 udp_setsockopt+0x73/0xa0 net/ipv4/udp.c:2817
 sock_common_setsockopt+0x61/0x70 net/core/sock.c:3668
 __sys_setsockopt+0x1c3/0x230 net/socket.c:2271
 __do_sys_setsockopt net/socket.c:2282 [inline]
 __se_sys_setsockopt net/socket.c:2279 [inline]
 __x64_sys_setsockopt+0x66/0x80 net/socket.c:2279
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffff8881382d52c0 -> 0xffff888138893740

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19632 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00387-g534293368afa #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

Fix it by using READ_ONCE()/WRITE_ONCE() for all accesses to
stock->cached_objcg.

Link: https://lkml.kernel.org/r/20230502160839.361544-1-roman.gushchin@linux.dev
Fixes: bf4f059954 ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reported-by: syzbot+774c29891415ab0fd29d@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
  Link: https://lore.kernel.org/linux-mm/CACT4Y+ZfucZhM60YPphWiCLJr6+SGFhT+jjm8k1P-a_8Kkxsjg@mail.gmail.com/T/#t
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11 12:08:23 +02:00
..
damon mm/damon/ops-common: atomically test and clear young on ptes and pmds 2023-07-19 16:22:11 +02:00
kasan kasan: add kasan_tag_mismatch prototype 2023-07-23 13:49:32 +02:00
kfence mm: kfence: fix handling discontiguous page 2023-04-13 16:55:30 +02:00
kmsan mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush() 2023-04-26 14:28:41 +02:00
backing-dev.c writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs 2023-04-26 14:28:39 +02:00
balloon_compaction.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma_debug.c mm/cma_debug: show complete cma name in debugfs directories 2022-09-11 20:25:50 -07:00
cma_sysfs.c
cma.c Revert "mm/cma.c: remove redundant cma_mutex lock" 2022-05-13 15:11:26 -07:00
cma.h mm/cma: provide option to opt out from exposing pages on activation failure 2022-03-22 15:57:09 -07:00
compaction.c Revert "mm/compaction: fix set skip in fast_find_migrateblock" 2023-02-01 08:34:49 +01:00
debug_page_ref.c
debug_vm_pgtable.c docs: rename Documentation/vm to Documentation/mm 2022-06-27 12:52:53 -07:00
debug.c mm: remove the vma linked list 2022-09-26 19:46:26 -07:00
dmapool.c
early_ioremap.c mm/early_ioremap: declare early_memremap_pgprot_adjust() 2022-03-22 15:57:11 -07:00
fadvise.c riscv: compat: syscall: Add compat_sys_call_table implementation 2022-04-26 13:36:25 -07:00
failslab.c mm: fix unexpected changes to {failslab|fail_page_alloc}.attr 2022-11-22 18:50:44 -08:00
filemap.c mm/filemap: fix page end in filemap_get_read_batch 2023-02-22 12:59:49 +01:00
folio-compat.c mm: remove try_to_free_swap() 2022-10-03 14:02:53 -07:00
frontswap.c frontswap: don't call ->init if no ops are registered 2022-09-26 12:14:34 -07:00
gup_test.c mm: rename is_pinnable_page() to is_longterm_pinnable_page() 2022-07-17 17:14:27 -07:00
gup_test.h
gup.c mm: always expand the stack with the mmap write lock held 2023-07-01 13:16:25 +02:00
highmem.c highmem: fix kmap_to_page() for kmap_local_page() addresses 2022-10-12 18:51:51 -07:00
hmm.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
huge_memory.c mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO 2023-04-26 14:28:41 +02:00
hugetlb_cgroup.c hugetlb_cgroup: use helper for_each_hstate and hstate_index 2022-09-11 20:25:53 -07:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: include missing linux/moduleparam.h 2022-11-08 15:57:23 -08:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability 2022-08-08 18:06:43 -07:00
hugetlb.c mm/hugetlb: fix uffd wr-protection for CoW optimization path 2023-04-13 16:55:36 +02:00
hwpoison-inject.c mm/hwpoison: add __init/__exit annotations to module init/exit funcs 2022-10-03 14:03:05 -07:00
init-mm.c mm: remove rb tree. 2022-09-26 19:46:16 -07:00
internal.h mm/page_alloc: make boot_nodestats static 2022-10-03 14:03:30 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: Add ioremap/iounmap_allowed() 2022-06-27 12:22:31 +01:00
Kconfig mm: introduce new 'lock_mm_and_find_vma()' page fault helper 2023-07-01 13:16:24 +02:00
Kconfig.debug mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM 2023-06-14 11:15:29 +02:00
khugepaged.c mm/khugepaged: check again on anon uffd-wp during isolation 2023-04-26 14:28:41 +02:00
kmemleak.c mm/kmemleak: prevent soft lockup in kmemleak_scan()'s object iteration loops 2022-10-28 13:37:22 -07:00
ksm.c mm/ksm: fix race with VMA iteration and mm_struct teardown 2023-03-30 12:49:29 +02:00
list_lru.c mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe 2022-06-16 19:48:31 -07:00
maccess.c mm: Fix copy_from_user_nofault(). 2023-06-28 11:12:17 +02:00
madvise.c use less confusing names for iov_iter direction initializers 2023-02-09 11:28:04 +01:00
Makefile mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol 2022-10-03 14:03:36 -07:00
mapping_dirty_helpers.c
memblock.c Revert "mm: Always release pages to the buddy allocator in memblock_free_late()." 2023-02-22 12:59:50 +01:00
memcontrol.c mm: kmem: fix a NULL pointer dereference in obj_stock_flush_required() 2023-08-11 12:08:23 +02:00
memfd.c memfd: check for non-NULL file_seals in memfd_create() syscall 2023-06-28 11:12:27 +02:00
memory_hotplug.c mm: add pageblock_aligned() macro 2022-10-03 14:03:04 -07:00
memory-failure.c mm/hwpoison: convert TTU_IGNORE_HWPOISON to TTU_HWPOISON 2023-03-10 09:34:25 +01:00
memory-tiers.c memory tier: release the new_memtier in find_create_memory_tier() 2023-03-10 09:34:27 +01:00
memory.c mm: call arch_swap_restore() from do_swap_page() 2023-07-19 16:21:16 +02:00
mempolicy.c mm/mempolicy: correctly update prev when policy is equal on mbind 2023-05-11 23:03:41 +09:00
mempool.c mm/mempool: use might_alloc() 2022-06-16 19:48:30 -07:00
memremap.c mm/memremap.c: map FS_DAX device memory as decrypted 2022-11-08 15:57:23 -08:00
memtest.c
migrate_device.c mm/migrate_device: return number of migrating pages in args->cpages 2022-11-22 18:50:43 -08:00
migrate.c mm/migrate: fix wrongly apply write bit after mkdirty on sparc64 2023-02-22 12:59:49 +01:00
mincore.c mm: teach mincore_hugetlb about pte markers 2023-03-22 13:34:03 +01:00
mlock.c mm/mlock: drop dead code in count_mm_mlocked_page_nr() 2022-09-26 19:46:27 -07:00
mm_init.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mm_slot.h mm: introduce common struct mm_slot 2022-10-03 14:02:43 -07:00
mmap_lock.c
mmap.c mm/mmap: Fix extra maple tree write 2023-07-19 16:22:16 +02:00
mmu_gather.c mm/khugepaged: fix GUP-fast interaction by sending IPI 2022-11-30 14:49:42 -08:00
mmu_notifier.c mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() 2022-04-21 20:01:10 -07:00
mmzone.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mprotect.c mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in 2022-10-12 15:56:46 -07:00
mremap.c mm, mremap: fix mremap() expanding for vma's with vm_ops->close() 2023-02-09 11:28:22 +01:00
msync.c mm/msync: use vma_find() instead of vma linked list 2022-09-26 19:46:25 -07:00
nommu.c xtensa: fix lock_mm_and_find_vma in case VMA not found 2023-07-05 18:27:37 +01:00
oom_kill.c mm: reduce noise in show_mem for lowmem allocations 2022-09-26 19:46:29 -07:00
page_alloc.c mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock 2023-04-26 14:28:44 +02:00
page_counter.c mm: page_counter: remove unneeded atomic ops for low/min 2022-09-11 20:26:01 -07:00
page_ext.c mm/page_exit: fix kernel doc warning in page_ext_put() 2022-11-22 18:50:41 -08:00
page_idle.c mm: don't be stuck to rmap lock on reclaim path 2022-05-19 14:08:54 -07:00
page_io.c use less confusing names for iov_iter direction initializers 2023-02-09 11:28:04 +01:00
page_isolation.c mm/page_isolation: fix clang deadcode warning 2022-10-28 13:37:22 -07:00
page_owner.c mm: reuse pageblock_start/end_pfn() macro 2022-10-03 14:03:03 -07:00
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c mm: page_table_check: Ensure user pages are not slab pages 2023-06-14 11:15:29 +02:00
page_vma_mapped.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
page-writeback.c mm: export balance_dirty_pages_ratelimited_flags() 2022-09-26 12:28:07 +02:00
pagewalk.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
percpu-internal.h percpu: improve percpu_alloc_percpu event trace 2022-05-13 07:20:18 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free() 2022-07-17 17:14:47 -07:00
pgalloc-track.h
pgtable-generic.c mm: avoid unnecessary flush on change_huge_pmd() 2022-05-13 07:20:05 -07:00
process_vm_access.c use less confusing names for iov_iter direction initializers 2023-02-09 11:28:04 +01:00
ptdump.c mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
readahead.c mm: add PSI accounting around ->read_folio and ->readahead calls 2022-09-20 08:24:38 -06:00
rmap.c mm/hwpoison: convert TTU_IGNORE_HWPOISON to TTU_HWPOISON 2023-03-10 09:34:25 +01:00
rodata_test.c mm/rodata_test: use PAGE_ALIGNED() helper 2022-10-03 14:03:05 -07:00
secretmem.c mm/secretmem: remove reduntant return value 2022-10-03 14:03:36 -07:00
shmem.c shmem: use ramfs_kill_sb() for kill_sb method of ramfs-based tmpfs 2023-07-19 16:22:11 +02:00
shrinker_debug.c mm: shrinkers: fix deadlock in shrinker debugfs 2023-02-22 12:59:46 +01:00
shuffle.c mm/shuffle: convert module_param_call to module_param_cb 2022-10-03 14:03:07 -07:00
shuffle.h
slab_common.c mm, slab: remove duplicate kernel-doc comment for ksize() 2022-11-07 17:11:27 +01:00
slab.c mm/slab: Fix undefined init_cache_node_node() for NUMA and !SMP 2023-03-30 12:49:23 +02:00
slab.h - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
slob.c Merge branch 'slab/for-6.1/kmalloc_size_roundup' into slab/for-next 2022-09-29 11:30:55 +02:00
slub.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
sparse-vmemmap.c mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c 2022-08-08 18:06:42 -07:00
sparse.c mm: memory_hotplug: enumerate all supported section flags 2022-07-03 18:08:49 -07:00
swap_cgroup.c mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled 2022-10-03 14:03:36 -07:00
swap_slots.c mm/swap: convert put_swap_page() to put_swap_folio() 2022-10-03 14:02:46 -07:00
swap_state.c swap_state: convert free_swap_cache() to use a folio 2022-10-03 14:02:51 -07:00
swap.c mm: add folio_add_lru_vma() 2022-10-03 14:02:45 -07:00
swap.h mm: remove lookup_swap_cache() 2022-10-03 14:02:51 -07:00
swapfile.c mm/swap: fix swap_info_struct race between swapoff and get_swap_pages() 2023-04-13 16:55:36 +02:00
truncate.c mm: add split_folio() 2022-10-03 14:02:45 -07:00
usercopy.c mm: Fix copy_from_user_nofault(). 2023-06-28 11:12:17 +02:00
userfaultfd.c mm/shmem: use page_mapping() to detect page cache for uffd continue 2022-11-08 15:57:23 -08:00
util.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
vmalloc.c mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush() 2023-04-26 14:28:41 +02:00
vmpressure.c
vmscan.c mm: do not reclaim private data from pinned page 2023-05-11 23:03:39 +09:00
vmstat.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
workingset.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
z3fold.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
zbud.c
zpool.c
zsmalloc.c zsmalloc: zs_destroy_pool: add size_class NULL check 2022-10-20 21:27:21 -07:00
zswap.c zswap: do not shrink if cgroup may not zswap 2023-06-21 16:00:54 +02:00