[syzbot] [xfs?] KASAN: slab-use-after-free Read in xfs_buf_rele (2)

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Dec 9, 2024, 6:23:28 AMDec 9
to c...@kernel.org, chanda...@oracle.com, djw...@kernel.org, linux-...@vger.kernel.org, linu...@vger.kernel.org, syzkall...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 7af08b57bcb9 Merge tag 'trace-v6.13-2' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17cecd30580000
kernel config: https://syzkaller.appspot.com/x/.config?x=129a9798def93175
dashboard link: https://syzkaller.appspot.com/bug?extid=643ffa707a94e3d66378
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/f6e67f04bc76/disk-7af08b57.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/31932bddea1f/vmlinux-7af08b57.xz
kernel image: https://storage.googleapis.com/syzbot-assets/62707034e0dd/bzImage-7af08b57.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+643ffa...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in rht_key_hashfn include/linux/rhashtable.h:159 [inline]
BUG: KASAN: slab-use-after-free in rht_head_hashfn include/linux/rhashtable.h:174 [inline]
BUG: KASAN: slab-use-after-free in __rhashtable_remove_fast_one include/linux/rhashtable.h:1007 [inline]
BUG: KASAN: slab-use-after-free in __rhashtable_remove_fast include/linux/rhashtable.h:1093 [inline]
BUG: KASAN: slab-use-after-free in rhashtable_remove_fast include/linux/rhashtable.h:1122 [inline]
BUG: KASAN: slab-use-after-free in xfs_buf_rele_cached fs/xfs/xfs_buf.c:1125 [inline]
BUG: KASAN: slab-use-after-free in xfs_buf_rele+0xd26/0x15b0 fs/xfs/xfs_buf.c:1151
Read of size 4 at addr ffff888033dd6c08 by task syz.7.96/6977

CPU: 1 UID: 0 PID: 6977 Comm: syz.7.96 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x169/0x550 mm/kasan/report.c:489
kasan_report+0x143/0x180 mm/kasan/report.c:602
rht_key_hashfn include/linux/rhashtable.h:159 [inline]
rht_head_hashfn include/linux/rhashtable.h:174 [inline]
__rhashtable_remove_fast_one include/linux/rhashtable.h:1007 [inline]
__rhashtable_remove_fast include/linux/rhashtable.h:1093 [inline]
rhashtable_remove_fast include/linux/rhashtable.h:1122 [inline]
xfs_buf_rele_cached fs/xfs/xfs_buf.c:1125 [inline]
xfs_buf_rele+0xd26/0x15b0 fs/xfs/xfs_buf.c:1151
xfs_buftarg_shrink_scan+0x264/0x300 fs/xfs/xfs_buf.c:2001
do_shrink_slab+0x72d/0x1160 mm/shrinker.c:437
shrink_slab+0x1093/0x14d0 mm/shrinker.c:664
drop_slab_node mm/vmscan.c:414 [inline]
drop_slab+0x142/0x280 mm/vmscan.c:432
drop_caches_sysctl_handler+0xbc/0x160 fs/drop_caches.c:68
proc_sys_call_handler+0x5ec/0x920 fs/proc/proc_sysctl.c:601
do_iter_readv_writev+0x600/0x880
vfs_writev+0x376/0xba0 fs/read_write.c:1050
do_writev+0x1b6/0x360 fs/read_write.c:1096
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
RIP: 0033:0x7fd7c0780809
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd7be5f6058 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fd7c0945fa0 RCX: 00007fd7c0780809
RDX: 0000000000000001 RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 00007fd7c07f393e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd7c0945fa0 R15: 00007fffcac00d18
</TASK>

Allocated by task 6968:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4283 [inline]
__kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4289
__kvmalloc_node_noprof+0x72/0x190 mm/util.c:650
bucket_table_alloc lib/rhashtable.c:186 [inline]
rhashtable_init_noprof+0x534/0xa60 lib/rhashtable.c:1071
xfs_perag_alloc fs/xfs/libxfs/xfs_ag.c:238 [inline]
xfs_initialize_perag+0x26a/0x630 fs/xfs/libxfs/xfs_ag.c:279
xfs_mountfs+0xaaf/0x2410 fs/xfs/xfs_mount.c:831
xfs_fs_fill_super+0x12db/0x1590 fs/xfs/xfs_super.c:1791
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3507
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
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 5852:
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:582
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:233 [inline]
slab_free_hook mm/slub.c:2338 [inline]
slab_free mm/slub.c:4598 [inline]
kfree+0x196/0x430 mm/slub.c:4746
rhashtable_free_and_destroy+0x7c6/0x920 lib/rhashtable.c:1169
xfs_group_free+0xd4/0x230 fs/xfs/libxfs/xfs_group.c:170
xfs_free_perag_range+0x36/0x60 fs/xfs/libxfs/xfs_ag.c:133
xfs_unmountfs+0x24d/0x2e0 fs/xfs/xfs_mount.c:1185
xfs_fs_put_super+0x65/0x150 fs/xfs/xfs_super.c:1149
generic_shutdown_super+0x139/0x2d0 fs/super.c:642
kill_block_super+0x44/0x90 fs/super.c:1710
xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2089
deactivate_locked_super+0xc4/0x130 fs/super.c:473
cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
task_work_run+0x24f/0x310 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888033dd6c00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 8 bytes inside of
freed 512-byte region [ffff888033dd6c00, ffff888033dd6e00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33dd4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801ac41c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff88801ac41c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 00fff00000000002 ffffea0000cf7501 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5216, tgid 5216 (udevadm), ts 27719249718, free_ts 27704552099
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
prep_new_page mm/page_alloc.c:1564 [inline]
get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3474
__alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
alloc_slab_page+0x6a/0x140 mm/slub.c:2408
allocate_slab+0x5a/0x2f0 mm/slub.c:2574
new_slab mm/slub.c:2627 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815
__slab_alloc+0x58/0xa0 mm/slub.c:3905
__slab_alloc_node mm/slub.c:3980 [inline]
slab_alloc_node mm/slub.c:4141 [inline]
__kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4309
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
kernfs_fop_open+0x3e0/0xd10 fs/kernfs/file.c:623
do_dentry_open+0xbe1/0x1b70 fs/open.c:945
vfs_open+0x3e/0x330 fs/open.c:1075
do_open fs/namei.c:3828 [inline]
path_openat+0x2c84/0x3590 fs/namei.c:3987
do_filp_open+0x27f/0x4e0 fs/namei.c:4014
do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_openat fs/open.c:1433 [inline]
__se_sys_openat fs/open.c:1428 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1428
page last free pid 5227 tgid 5227 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_unref_page+0xde3/0x1130 mm/page_alloc.c:2657
discard_slab mm/slub.c:2673 [inline]
__put_partials+0xeb/0x130 mm/slub.c:3142
put_cpu_partial+0x17c/0x250 mm/slub.c:3217
__slab_free+0x2ea/0x3d0 mm/slub.c:4468
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9a/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:250 [inline]
slab_post_alloc_hook mm/slub.c:4104 [inline]
slab_alloc_node mm/slub.c:4153 [inline]
kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4160
alloc_empty_file+0x9e/0x1d0 fs/file_table.c:228
path_openat+0x107/0x3590 fs/namei.c:3973
do_filp_open+0x27f/0x4e0 fs/namei.c:4014
do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_openat fs/open.c:1433 [inline]
__se_sys_openat fs/open.c:1428 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1428
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:
ffff888033dd6b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888033dd6b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888033dd6c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888033dd6c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888033dd6d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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