Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in qd_unlock
RSP: 002b:00007fffad5dbb18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f3b10c8d567
RDX: 00007fffad5dbbe9 RSI: 000000000000000a RDI: 00007fffad5dbbe0
RBP: 00007fffad5dbbe0 R08: 00000000ffffffff R09: 00007fffad5db9b0
R10: 00005555555e18b3 R11: 0000000000000246 R12: 00007f3b10ce6b24
R13: 00007fffad5dcca0 R14: 00005555555e1810 R15: 00007fffad5dcce0
</TASK>
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: use-after-free in qd_unlock+0x20/0x190 fs/gfs2/quota.c:490
Read of size 8 at addr ffff888072ba0090 by task syz-executor.0/5530
CPU: 1 PID: 5530 Comm: syz-executor.0 Not tainted 6.2.0-rc1-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:306 [inline]
print_report+0x15e/0x45d mm/kasan/report.c:417
kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x141/0x190 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:72 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
qd_unlock+0x20/0x190 fs/gfs2/quota.c:490
gfs2_quota_sync+0x39d/0x660 fs/gfs2/quota.c:1325
gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:650
sync_filesystem.part.0+0x75/0x1d0 fs/sync.c:56
sync_filesystem+0x8f/0xc0 fs/sync.c:43
generic_shutdown_super+0x74/0x410 fs/super.c:474
kill_block_super+0x9b/0xf0 fs/super.c:1386
gfs2_kill_sb+0x108/0x170 fs/gfs2/ops_fstype.c:1738
deactivate_locked_super+0x98/0x160 fs/super.c:332
deactivate_super+0xb1/0xd0 fs/super.c:363
cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291
task_work_run+0x16f/0x270 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f3b10c8d567
Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffad5dbb18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f3b10c8d567
RDX: 00007fffad5dbbe9 RSI: 000000000000000a RDI: 00007fffad5dbbe0
RBP: 00007fffad5dbbe0 R08: 00000000ffffffff R09: 00007fffad5db9b0
R10: 00005555555e18b3 R11: 0000000000000246 R12: 00007f3b10ce6b24
R13: 00007fffad5dcca0 R14: 00005555555e1810 R15: 00007fffad5dcce0
</TASK>
Allocated by task 5604:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x82/0x90 mm/kasan/common.c:325
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slab.h:761 [inline]
slab_alloc_node mm/slub.c:3452 [inline]
slab_alloc mm/slub.c:3460 [inline]
__kmem_cache_alloc_lru mm/slub.c:3467 [inline]
kmem_cache_alloc+0x1e4/0x430 mm/slub.c:3476
kmem_cache_zalloc include/linux/slab.h:710 [inline]
qd_alloc+0x4e/0x300 fs/gfs2/quota.c:216
gfs2_quota_init+0x7bb/0xf70 fs/gfs2/quota.c:1415
gfs2_make_fs_rw+0x424/0x640 fs/gfs2/super.c:153
gfs2_fill_super+0x22c8/0x27a0 fs/gfs2/ops_fstype.c:1274
get_tree_bdev+0x444/0x760 fs/super.c:1282
gfs2_get_tree+0x4e/0x270 fs/gfs2/ops_fstype.c:1330
vfs_get_tree+0x8d/0x2f0 fs/super.c:1489
do_new_mount fs/namespace.c:3145 [inline]
path_mount+0x132a/0x1e20 fs/namespace.c:3475
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount fs/namespace.c:3674 [inline]
__x64_sys_mount+0x283/0x300 fs/namespace.c:3674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 5530:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1781 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
slab_free mm/slub.c:3787 [inline]
kmem_cache_free+0xee/0x5c0 mm/slub.c:3809
rcu_do_batch kernel/rcu/tree.c:2246 [inline]
rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2506
__do_softirq+0x1fb/0xadc kernel/softirq.c:571
Last potentially related work creation:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
__kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
__call_rcu_common.constprop.0+0x99/0x820 kernel/rcu/tree.c:2755
gfs2_quota_cleanup+0x483/0x860 fs/gfs2/quota.c:1479
gfs2_make_fs_ro+0x202/0x610 fs/gfs2/super.c:560
signal_our_withdraw fs/gfs2/util.c:166 [inline]
gfs2_withdraw.cold+0x4b4/0xf9a fs/gfs2/util.c:351
gfs2_dinode_in fs/gfs2/glops.c:457 [inline]
gfs2_inode_refresh+0xbf8/0xf60 fs/gfs2/glops.c:477
inode_go_instantiate+0x4a/0x70 fs/gfs2/glops.c:496
gfs2_instantiate+0x16a/0x250 fs/gfs2/glock.c:456
gfs2_glock_holder_ready fs/gfs2/glock.c:1299 [inline]
gfs2_glock_holder_ready fs/gfs2/glock.c:1295 [inline]
gfs2_glock_wait+0x197/0x2e0 fs/gfs2/glock.c:1319
gfs2_glock_nq+0xae4/0x1470 fs/gfs2/glock.c:1567
gfs2_glock_nq_init fs/gfs2/glock.h:262 [inline]
do_sync+0x62f/0xcf0 fs/gfs2/quota.c:916
gfs2_quota_sync+0x2e6/0x660 fs/gfs2/quota.c:1318
gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:650
sync_filesystem.part.0+0x75/0x1d0 fs/sync.c:56
sync_filesystem+0x8f/0xc0 fs/sync.c:43
generic_shutdown_super+0x74/0x410 fs/super.c:474
kill_block_super+0x9b/0xf0 fs/super.c:1386
gfs2_kill_sb+0x108/0x170 fs/gfs2/ops_fstype.c:1738
deactivate_locked_super+0x98/0x160 fs/super.c:332
deactivate_super+0xb1/0xd0 fs/super.c:363
cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291
task_work_run+0x16f/0x270 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888072ba0000
which belongs to the cache gfs2_quotad of size 272
The buggy address is located 144 bytes inside of
272-byte region [ffff888072ba0000, ffff888072ba0110)
The buggy address belongs to the physical page:
page:ffffea0001cae800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x72ba0
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff888018fab140 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x112c50(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 5604, tgid 5603 (syz-executor.0), ts 62041431121, free_ts 61836511251
prep_new_page mm/page_alloc.c:2531 [inline]
get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283
__alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286
alloc_slab_page mm/slub.c:1851 [inline]
allocate_slab+0x25f/0x350 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0xa91/0x1400 mm/slub.c:3193
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
__slab_alloc_node mm/slub.c:3345 [inline]
slab_alloc_node mm/slub.c:3442 [inline]
slab_alloc mm/slub.c:3460 [inline]
__kmem_cache_alloc_lru mm/slub.c:3467 [inline]
kmem_cache_alloc+0x379/0x430 mm/slub.c:3476
kmem_cache_zalloc include/linux/slab.h:710 [inline]
qd_alloc+0x4e/0x300 fs/gfs2/quota.c:216
gfs2_quota_init+0x7bb/0xf70 fs/gfs2/quota.c:1415
gfs2_make_fs_rw+0x424/0x640 fs/gfs2/super.c:153
gfs2_fill_super+0x22c8/0x27a0 fs/gfs2/ops_fstype.c:1274
get_tree_bdev+0x444/0x760 fs/super.c:1282
gfs2_get_tree+0x4e/0x270 fs/gfs2/ops_fstype.c:1330
vfs_get_tree+0x8d/0x2f0 fs/super.c:1489
do_new_mount fs/namespace.c:3145 [inline]
path_mount+0x132a/0x1e20 fs/namespace.c:3475
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount fs/namespace.c:3674 [inline]
__x64_sys_mount+0x283/0x300 fs/namespace.c:3674
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1446 [inline]
free_pcp_prepare+0x66a/0xc20 mm/page_alloc.c:1496
free_unref_page_prepare mm/page_alloc.c:3369 [inline]
free_unref_page+0x1d/0x490 mm/page_alloc.c:3464
__unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slab.h:761 [inline]
slab_alloc_node mm/slub.c:3452 [inline]
slab_alloc mm/slub.c:3460 [inline]
__kmem_cache_alloc_lru mm/slub.c:3467 [inline]
kmem_cache_alloc+0x1e4/0x430 mm/slub.c:3476
getname_flags.part.0+0x50/0x4f0 fs/namei.c:139
getname_flags include/linux/audit.h:320 [inline]
getname fs/namei.c:218 [inline]
__do_sys_unlink fs/namei.c:4368 [inline]
__se_sys_unlink fs/namei.c:4366 [inline]
__x64_sys_unlink+0xb5/0x110 fs/namei.c:4366
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Memory state around the buggy address:
ffff888072b9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888072ba0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888072ba0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888072ba0100: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888072ba0180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
console output:
https://syzkaller.appspot.com/x/log.txt?x=15c72b98c80000
kernel config:
https://syzkaller.appspot.com/x/.config?x=7a23fb7114ed14bf
dashboard link:
https://syzkaller.appspot.com/bug?extid=3f6a670108ce43356017
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:
https://syzkaller.appspot.com/x/patch.diff?x=1122c638c80000