[syzbot] [mm?] KASAN: slab-use-after-free Read in folio_evictable (3)

syzbot
2024-11-26T02:41:26Z

Hello,

syzbot found the following issue on:

HEAD commit: 4a39ac5b7d62 Merge tag 'random-6.12-rc1-for-linus' of git:..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16caa607980000
kernel config: https://syzkaller.appspot.com/x/.config?x=dd14c10ec1b6af25
dashboard link: https://syzkaller.appspot.com/bug?extid=4c7590f1cee06597e43a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3ee480a33b34/disk-4a39ac5b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/73587a04fea1/vmlinux-4a39ac5b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/67e463731a48/bzImage-4a39ac5b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4c7590f1cee06597e43a@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in mapping_unevictable include/linux/pagemap.h:262 [inline]
BUG: KASAN: slab-use-after-free in folio_evictable+0xe3/0x310 mm/internal.h:370
Read of size 8 at addr ffff888024afbf90 by task kswapd0/89

CPU: 1 UID: 0 PID: 89 Comm: kswapd0 Not tainted 6.11.0-syzkaller-05319-g4a39ac5b7d62 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
mapping_unevictable include/linux/pagemap.h:262 [inline]
folio_evictable+0xe3/0x310 mm/internal.h:370
sort_folio mm/vmscan.c:4275 [inline]
scan_folios mm/vmscan.c:4392 [inline]
isolate_folios mm/vmscan.c:4517 [inline]
evict_folios+0x1023/0x7780 mm/vmscan.c:4548
try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4755
shrink_one+0x3b9/0x850 mm/vmscan.c:4793
shrink_many mm/vmscan.c:4856 [inline]
lru_gen_shrink_node mm/vmscan.c:4934 [inline]
shrink_node+0x3799/0x3de0 mm/vmscan.c:5914
kswapd_shrink_node mm/vmscan.c:6742 [inline]
balance_pgdat mm/vmscan.c:6934 [inline]
kswapd+0x1cbc/0x3720 mm/vmscan.c:7203
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 22175:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4086 [inline]
slab_alloc_node mm/slub.c:4135 [inline]
kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142
getname_flags+0xb7/0x540 fs/namei.c:139
vfs_fstatat+0x12c/0x190 fs/stat.c:340
__do_sys_newfstatat fs/stat.c:505 [inline]
__se_sys_newfstatat fs/stat.c:499 [inline]
__x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 22175:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:2343 [inline]
slab_free mm/slub.c:4580 [inline]
kmem_cache_free+0x1a3/0x420 mm/slub.c:4682
vfs_fstatat+0x14f/0x190 fs/stat.c:342
__do_sys_newfstatat fs/stat.c:505 [inline]
__se_sys_newfstatat fs/stat.c:499 [inline]
__x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888024afb300
which belongs to the cache names_cache of size 4096
The buggy address is located 3216 bytes inside of
freed 4096-byte region [ffff888024afb300, ffff888024afc300)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24af8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000040 ffff88801bafc780 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000070007 00000001fdffffff 0000000000000000
head: 00fff00000000040 ffff88801bafc780 dead000000000122 0000000000000000
head: 0000000000000000 0000000000070007 00000001fdffffff 0000000000000000
head: 00fff00000000003 ffffea000092be01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 22175, tgid 22175 (sed), ts 1028936253921, free_ts 1028792054212
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1500
prep_new_page mm/page_alloc.c:1508 [inline]
get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3446
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4702
alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263
alloc_slab_page+0x6a/0x130 mm/slub.c:2413
allocate_slab+0x5a/0x2f0 mm/slub.c:2579
new_slab mm/slub.c:2632 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
__slab_alloc+0x58/0xa0 mm/slub.c:3909
__slab_alloc_node mm/slub.c:3962 [inline]
slab_alloc_node mm/slub.c:4123 [inline]
kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4142
getname_flags+0xb7/0x540 fs/namei.c:139
do_sys_openat2+0xd2/0x1d0 fs/open.c:1409
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 22169 tgid 22169 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1101 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2619
discard_slab mm/slub.c:2678 [inline]
__put_partials+0xeb/0x130 mm/slub.c:3146
put_cpu_partial+0x17c/0x250 mm/slub.c:3221
__slab_free+0x2ea/0x3d0 mm/slub.c:4450
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4086 [inline]
slab_alloc_node mm/slub.c:4135 [inline]
kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142
getname_flags+0xb7/0x540 fs/namei.c:139
vfs_fstatat+0x12c/0x190 fs/stat.c:340
__do_sys_newfstatat fs/stat.c:505 [inline]
__se_sys_newfstatat fs/stat.c:499 [inline]
__x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff888024afbe80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888024afbf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888024afbf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888024afc000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888024afc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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