[syzbot] [gfs2?] KASAN: use-after-free Read in qd_unlock (2)

From: syzbot
Date: Mon Jan 02 2023 - 16:20:50 EST


Hello,

syzbot found the following issue on:

HEAD commit: 1b929c02afd3 Linux 6.2-rc1
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1799c250480000
kernel config: https://syzkaller.appspot.com/x/.config?x=68e0be42c8ee4bb4
dashboard link: https://syzkaller.appspot.com/bug?extid=3f6a670108ce43356017
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14c4ea18480000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1359b338480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2d8c5072480f/disk-1b929c02.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/46687f1395db/vmlinux-1b929c02.xz
kernel image: https://storage.googleapis.com/syzbot-assets/26f1afa5ec00/bzImage-1b929c02.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/35edd581b491/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3f6a670108ce43356017@xxxxxxxxxxxxxxxxxxxxxxxxx

R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2c431103d0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</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+0x30/0x2d0 fs/gfs2/quota.c:490
Read of size 8 at addr ffff888073997090 by task syz-executor221/5069

CPU: 1 PID: 5069 Comm: syz-executor221 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:306
print_report+0x107/0x1f0 mm/kasan/report.c:417
kasan_report+0xcd/0x100 mm/kasan/report.c:517
kasan_check_range+0x2a7/0x2e0 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+0x30/0x2d0 fs/gfs2/quota.c:490
gfs2_quota_sync+0x768/0x8b0 fs/gfs2/quota.c:1325
gfs2_sync_fs+0x49/0xb0 fs/gfs2/super.c:650
sync_filesystem+0xe8/0x220 fs/sync.c:56
generic_shutdown_super+0x6b/0x310 fs/super.c:474
kill_block_super+0x79/0xd0 fs/super.c:1386
deactivate_locked_super+0xa7/0xf0 fs/super.c:332
cleanup_mnt+0x494/0x520 fs/namespace.c:1291
task_work_run+0x243/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x644/0x2150 kernel/exit.c:867
do_group_exit+0x1fd/0x2b0 kernel/exit.c:1012
__do_sys_exit_group kernel/exit.c:1023 [inline]
__se_sys_exit_group kernel/exit.c:1021 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1021
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f2c4308d0c9
Code: Unable to access opcode bytes at 0x7f2c4308d09f.
RSP: 002b:00007ffcdd2f81f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f2c431103d0 RCX: 00007f2c4308d0c9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffffffffffc0 R09: 0000000000012550
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2c431103d0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>

Allocated by task 5069:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x3d/0x60 mm/kasan/common.c:52
__kasan_slab_alloc+0x65/0x70 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+0x1b3/0x350 mm/slub.c:3476
kmem_cache_zalloc include/linux/slab.h:710 [inline]
qd_alloc+0x51/0x250 fs/gfs2/quota.c:216
gfs2_quota_init+0x7c4/0x10e0 fs/gfs2/quota.c:1415
gfs2_make_fs_rw+0x48e/0x590 fs/gfs2/super.c:153
gfs2_fill_super+0x2357/0x2700 fs/gfs2/ops_fstype.c:1274
get_tree_bdev+0x400/0x620 fs/super.c:1282
gfs2_get_tree+0x50/0x210 fs/gfs2/ops_fstype.c:1330
vfs_get_tree+0x88/0x270 fs/super.c:1489
do_new_mount+0x289/0xad0 fs/namespace.c:3145
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 0:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x3d/0x60 mm/kasan/common.c:52
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:518
____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1781 [inline]
slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1807
slab_free mm/slub.c:3787 [inline]
kmem_cache_free+0x94/0x1d0 mm/slub.c:3809
rcu_do_batch kernel/rcu/tree.c:2246 [inline]
rcu_core+0x9c1/0x1690 kernel/rcu/tree.c:2506
__do_softirq+0x277/0x738 kernel/softirq.c:571

Last potentially related work creation:
kasan_save_stack+0x2b/0x50 mm/kasan/common.c:45
__kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:488
__call_rcu_common kernel/rcu/tree.c:2755 [inline]
call_rcu+0x163/0xa70 kernel/rcu/tree.c:2868
gfs2_quota_cleanup+0x457/0x6b0 fs/gfs2/quota.c:1479
gfs2_make_fs_ro+0x517/0x610 fs/gfs2/super.c:560
signal_our_withdraw fs/gfs2/util.c:166 [inline]
gfs2_withdraw+0x609/0x1540 fs/gfs2/util.c:351
gfs2_dinode_in fs/gfs2/glops.c:460 [inline]
gfs2_inode_refresh+0xb2d/0xf60 fs/gfs2/glops.c:480
gfs2_instantiate+0x15e/0x220 fs/gfs2/glock.c:456
gfs2_glock_holder_ready fs/gfs2/glock.c:1299 [inline]
gfs2_glock_wait+0x1d9/0x2a0 fs/gfs2/glock.c:1319
gfs2_glock_nq_init fs/gfs2/glock.h:262 [inline]
do_sync+0x485/0xc80 fs/gfs2/quota.c:916
gfs2_quota_sync+0x3da/0x8b0 fs/gfs2/quota.c:1318
gfs2_sync_fs+0x49/0xb0 fs/gfs2/super.c:650
sync_filesystem+0xe8/0x220 fs/sync.c:56
generic_shutdown_super+0x6b/0x310 fs/super.c:474
kill_block_super+0x79/0xd0 fs/super.c:1386
deactivate_locked_super+0xa7/0xf0 fs/super.c:332
cleanup_mnt+0x494/0x520 fs/namespace.c:1291
task_work_run+0x243/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x644/0x2150 kernel/exit.c:867
do_group_exit+0x1fd/0x2b0 kernel/exit.c:1012
__do_sys_exit_group kernel/exit.c:1023 [inline]
__se_sys_exit_group kernel/exit.c:1021 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1021
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888073997000
which belongs to the cache gfs2_quotad of size 272
The buggy address is located 144 bytes inside of
272-byte region [ffff888073997000, ffff888073997110)

The buggy address belongs to the physical page:
page:ffffea0001ce65c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73997
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff8881461ae500 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 0x12c50(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 5069, tgid 5069 (syz-executor221), ts 50927644511, free_ts 12661541703
prep_new_page mm/page_alloc.c:2531 [inline]
get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4283
__alloc_pages+0x259/0x560 mm/page_alloc.c:5549
alloc_slab_page+0xbd/0x190 mm/slub.c:1851
allocate_slab+0x5e/0x3c0 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0x782/0xe20 mm/slub.c:3193
__slab_alloc mm/slub.c:3292 [inline]
__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+0x268/0x350 mm/slub.c:3476
kmem_cache_zalloc include/linux/slab.h:710 [inline]
qd_alloc+0x51/0x250 fs/gfs2/quota.c:216
gfs2_quota_init+0x7c4/0x10e0 fs/gfs2/quota.c:1415
gfs2_make_fs_rw+0x48e/0x590 fs/gfs2/super.c:153
gfs2_fill_super+0x2357/0x2700 fs/gfs2/ops_fstype.c:1274
get_tree_bdev+0x400/0x620 fs/super.c:1282
gfs2_get_tree+0x50/0x210 fs/gfs2/ops_fstype.c:1330
vfs_get_tree+0x88/0x270 fs/super.c:1489
do_new_mount+0x289/0xad0 fs/namespace.c:3145
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
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+0x751/0x780 mm/page_alloc.c:1496
free_unref_page_prepare mm/page_alloc.c:3369 [inline]
free_unref_page+0x19/0x4c0 mm/page_alloc.c:3464
free_contig_range+0xa3/0x160 mm/page_alloc.c:9485
destroy_args+0xfe/0x940 mm/debug_vm_pgtable.c:998
debug_vm_pgtable+0x43d/0x4a0 mm/debug_vm_pgtable.c:1318
do_one_initcall+0x1d1/0x410 init/main.c:1306
do_initcall_level+0x168/0x220 init/main.c:1379
do_initcalls+0x43/0x90 init/main.c:1395
kernel_init_freeable+0x428/0x5e0 init/main.c:1634
kernel_init+0x19/0x2b0 init/main.c:1522
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Memory state around the buggy address:
ffff888073996f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888073997000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888073997080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888073997100: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888073997180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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