[v6.1] possible deadlock in dquot_commit

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syzbot

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Mar 7, 2023, 11:18:48 PM3/7/23
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 42616e0f09fb Linux 6.1.15
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=160d7fbcc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=650737f7e9682672
dashboard link: https://syzkaller.appspot.com/bug?extid=2519f87e4f1b003aaba2
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f10713d1fd0f/disk-42616e0f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5a1307bb774e/vmlinux-42616e0f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/388238a30fe4/Image-42616e0f.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2519f8...@syzkaller.appspotmail.com

EXT4-fs (loop4): mounted filesystem without journal. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
6.1.15-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/13272 is trying to acquire lock:
ffff0001029eece8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:479

but task is already holding lock:
ffff0000dcd85cd0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x794/0x1884 fs/ext4/inode.c:644

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
down_read+0x5c/0x78 kernel/locking/rwsem.c:1509
ext4_map_blocks+0x2ac/0x1884 fs/ext4/inode.c:574
ext4_getblk+0x198/0x6ec fs/ext4/inode.c:864
ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:920
ext4_quota_read+0x178/0x294 fs/ext4/super.c:7060
read_blk fs/quota/quota_tree.c:55 [inline]
find_tree_dqentry+0x164/0xa08 fs/quota/quota_tree.c:624
find_tree_dqentry+0x394/0xa08 fs/quota/quota_tree.c:640
find_tree_dqentry+0x394/0xa08 fs/quota/quota_tree.c:640
find_tree_dqentry+0x394/0xa08 fs/quota/quota_tree.c:640
find_dqentry fs/quota/quota_tree.c:652 [inline]
qtree_read_dquot+0x12c/0x634 fs/quota/quota_tree.c:672
v2_read_dquot+0xc0/0x11c fs/quota/quota_v2.c:333
dquot_acquire+0x130/0x5c4 fs/quota/dquot.c:435
ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6740
dqget+0x844/0xc48 fs/quota/dquot.c:914
__dquot_initialize+0x344/0xb54 fs/quota/dquot.c:1492
dquot_initialize+0x24/0x34 fs/quota/dquot.c:1550
ext4_process_orphan+0x5c/0x2b8 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0x99c/0x10e0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5517 [inline]
ext4_fill_super+0x6e68/0x74c8 fs/ext4/super.c:5645
get_tree_bdev+0x360/0x54c fs/super.c:1324
ext4_get_tree+0x28/0x38 fs/ext4/super.c:5675
vfs_get_tree+0x90/0x274 fs/super.c:1531
do_new_mount+0x25c/0x8c8 fs/namespace.c:3040
path_mount+0x590/0xe58 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3568
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
down_read+0x5c/0x78 kernel/locking/rwsem.c:1509
v2_read_dquot+0x50/0x11c fs/quota/quota_v2.c:332
dquot_acquire+0x130/0x5c4 fs/quota/dquot.c:435
ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6740
dqget+0x844/0xc48 fs/quota/dquot.c:914
__dquot_initialize+0x344/0xb54 fs/quota/dquot.c:1492
dquot_initialize+0x24/0x34 fs/quota/dquot.c:1550
ext4_xattr_set+0xe8/0x350 fs/ext4/xattr.c:2475
ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
__vfs_setxattr+0x388/0x3a4 fs/xattr.c:182
__vfs_setxattr_noperm+0x110/0x528 fs/xattr.c:216
__vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:277
vfs_setxattr+0x1a8/0x344 fs/xattr.c:309
do_setxattr fs/xattr.c:594 [inline]
setxattr+0x230/0x294 fs/xattr.c:617
path_setxattr+0x17c/0x258 fs/xattr.c:636
__do_sys_setxattr fs/xattr.c:652 [inline]
__se_sys_setxattr fs/xattr.c:648 [inline]
__arm64_sys_setxattr+0xbc/0xd8 fs/xattr.c:648
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5055
lock_acquire+0x2f8/0x8dc kernel/locking/lockdep.c:5668
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
dquot_commit+0x54/0x240 fs/quota/dquot.c:479
ext4_write_dquot+0x1b0/0x284 fs/ext4/super.c:6724
ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6772
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_alloc_space+0x47c/0xd00 fs/quota/dquot.c:1722
dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline]
dquot_alloc_space include/linux/quotaops.h:313 [inline]
dquot_alloc_block include/linux/quotaops.h:337 [inline]
ext4_mb_new_blocks+0x1020/0x49c8 fs/ext4/mballoc.c:5573
ext4_ext_map_blocks+0x1740/0x688c fs/ext4/extents.c:4287
ext4_map_blocks+0x828/0x1884 fs/ext4/inode.c:651
ext4_getblk+0x198/0x6ec fs/ext4/inode.c:864
ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:920
ext4_append+0x260/0x4cc fs/ext4/namei.c:83
ext4_init_new_dir+0x294/0x8e4 fs/ext4/namei.c:2956
ext4_mkdir+0x3d4/0xa64 fs/ext4/namei.c:3002
vfs_mkdir+0x334/0x4e4 fs/namei.c:4036
do_mkdirat+0x20c/0x610 fs/namei.c:4061
__do_sys_mkdirat fs/namei.c:4076 [inline]
__se_sys_mkdirat fs/namei.c:4074 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4074
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

Chain exists of:
&dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ei->i_data_sem/2);
lock(&s->s_dquot.dqio_sem);
lock(&ei->i_data_sem/2);
lock(&dquot->dq_lock);

*** DEADLOCK ***

4 locks held by syz-executor.4/13272:
#0: ffff0000c1c6e460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
#1: ffff0001041dac20 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:791 [inline]
#1: ffff0001041dac20 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x200/0x464 fs/namei.c:3807
#2: ffff0000dcd85cd0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x794/0x1884 fs/ext4/inode.c:644
#3: ffff800015a47728 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:303

stack backtrace:
CPU: 0 PID: 13272 Comm: syz-executor.4 Not tainted 6.1.15-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2055
check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5055
lock_acquire+0x2f8/0x8dc kernel/locking/lockdep.c:5668
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
dquot_commit+0x54/0x240 fs/quota/dquot.c:479
ext4_write_dquot+0x1b0/0x284 fs/ext4/super.c:6724
ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6772
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_alloc_space+0x47c/0xd00 fs/quota/dquot.c:1722
dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline]
dquot_alloc_space include/linux/quotaops.h:313 [inline]
dquot_alloc_block include/linux/quotaops.h:337 [inline]
ext4_mb_new_blocks+0x1020/0x49c8 fs/ext4/mballoc.c:5573
ext4_ext_map_blocks+0x1740/0x688c fs/ext4/extents.c:4287
ext4_map_blocks+0x828/0x1884 fs/ext4/inode.c:651
ext4_getblk+0x198/0x6ec fs/ext4/inode.c:864
ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:920
ext4_append+0x260/0x4cc fs/ext4/namei.c:83
ext4_init_new_dir+0x294/0x8e4 fs/ext4/namei.c:2956
ext4_mkdir+0x3d4/0xa64 fs/ext4/namei.c:3002
vfs_mkdir+0x334/0x4e4 fs/namei.c:4036
do_mkdirat+0x20c/0x610 fs/namei.c:4061
__do_sys_mkdirat fs/namei.c:4076 [inline]
__se_sys_mkdirat fs/namei.c:4074 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4074
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581


---
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See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot

unread,
Mar 8, 2023, 12:45:57 AM3/8/23
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: d9b4a0c83a2d Linux 5.15.98
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12683488c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=2f8d9515b973b23b
dashboard link: https://syzkaller.appspot.com/bug?extid=dbab76e22a05c7efc6d6
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/037cabbd3313/disk-d9b4a0c8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9967e551eb34/vmlinux-d9b4a0c8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a050c7a4fd99/bzImage-d9b4a0c8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dbab76...@syzkaller.appspotmail.com

EXT4-fs (loop3): mounted filesystem without journal. Opts: noquota,barrier,nouid32,grpquota,,errors=continue. Quota mode: writeback.
ext4 filesystem being mounted at /root/syzkaller-testdir2633985265/syzkaller.TY3Eqi/1235/file0 supports timestamps until 2038 (0x7fffffff)
======================================================
WARNING: possible circular locking dependency detected
5.15.98-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/23972 is trying to acquire lock:
ffff88804df87928 (&dquot->dq_lock){+.+.}-{3:3}
, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:479

but task is already holding lock:
ffff88804b705238 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x9e0/0x1e30 fs/ext4/inode.c:638

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
down_read+0x3b/0x50 kernel/locking/rwsem.c:1480
ext4_map_blocks+0x3a6/0x1e30 fs/ext4/inode.c:568
ext4_getblk+0x19f/0x710 fs/ext4/inode.c:856
ext4_bread+0x2a/0x170 fs/ext4/inode.c:909
ext4_quota_read+0x1a1/0x2c0 fs/ext4/super.c:6483
read_blk fs/quota/quota_tree.c:55 [inline]
find_tree_dqentry+0x192/0xb60 fs/quota/quota_tree.c:617
find_tree_dqentry+0x41a/0xb60 fs/quota/quota_tree.c:635
find_tree_dqentry+0x41a/0xb60 fs/quota/quota_tree.c:635
find_tree_dqentry+0x41a/0xb60 fs/quota/quota_tree.c:635
find_dqentry fs/quota/quota_tree.c:647 [inline]
qtree_read_dquot+0x13f/0x650 fs/quota/quota_tree.c:667
v2_read_dquot+0xbe/0x100 fs/quota/quota_v2.c:333
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6163
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xa5c/0x1260 fs/ext4/orphan.c:474
ext4_fill_super+0x9760/0x9f80 fs/ext4/super.c:4964
mount_bdev+0x26d/0x3a0 fs/super.c:1369
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1499
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
down_read+0x3b/0x50 kernel/locking/rwsem.c:1480
v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6163
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xa5c/0x1260 fs/ext4/orphan.c:474
ext4_fill_super+0x9760/0x9f80 fs/ext4/super.c:4964
mount_bdev+0x26d/0x3a0 fs/super.c:1369
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1499
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6147
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_alloc_space+0x53a/0xf30 fs/quota/dquot.c:1722
dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
dquot_alloc_space include/linux/quotaops.h:310 [inline]
dquot_alloc_block include/linux/quotaops.h:334 [inline]
ext4_mb_new_blocks+0x1365/0x50c0 fs/ext4/mballoc.c:5585
ext4_ext_map_blocks+0x1b0f/0x75e0 fs/ext4/extents.c:4287
ext4_map_blocks+0xaad/0x1e30 fs/ext4/inode.c:645
_ext4_get_block+0x23b/0x660 fs/ext4/inode.c:802
ext4_block_write_begin+0x6b0/0x13a0 fs/ext4/inode.c:1087
ext4_write_begin+0x776/0x16f0
ext4_da_write_begin+0x343/0xc40 fs/ext4/inode.c:2973
generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3776
ext4_buffered_write_iter+0x22e/0x380 fs/ext4/file.c:269
ext4_file_write_iter+0x87c/0x1990
call_write_iter include/linux/fs.h:2101 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0xacf/0xe50 fs/read_write.c:594
ksys_write+0x1a2/0x2c0 fs/read_write.c:647
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+0x61/0xcb

other info that might help us debug this:

Chain exists of:
&dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ei->i_data_sem/2);
lock(&s->s_dquot.dqio_sem);
lock(&ei->i_data_sem/2);
lock(&dquot->dq_lock);

*** DEADLOCK ***

5 locks held by syz-executor.3/23972:
#0: ffff88807b1265f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x261/0x300 fs/file.c:1072
#1: ffff88801e8fe460 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
#2: ffff88804b7053b0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#2: ffff88804b7053b0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xb9/0x380 fs/ext4/file.c:263
#3: ffff88804b705238 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x9e0/0x1e30 fs/ext4/inode.c:638
#4: ffffffff8ca3fbb8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:266

stack backtrace:
CPU: 1 PID: 23972 Comm: syz-executor.3 Not tainted 5.15.98-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6147
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_alloc_space+0x53a/0xf30 fs/quota/dquot.c:1722
dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
dquot_alloc_space include/linux/quotaops.h:310 [inline]
dquot_alloc_block include/linux/quotaops.h:334 [inline]
ext4_mb_new_blocks+0x1365/0x50c0 fs/ext4/mballoc.c:5585
ext4_ext_map_blocks+0x1b0f/0x75e0 fs/ext4/extents.c:4287
ext4_map_blocks+0xaad/0x1e30 fs/ext4/inode.c:645
_ext4_get_block+0x23b/0x660 fs/ext4/inode.c:802
ext4_block_write_begin+0x6b0/0x13a0 fs/ext4/inode.c:1087
ext4_write_begin+0x776/0x16f0
ext4_da_write_begin+0x343/0xc40 fs/ext4/inode.c:2973
generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3776
ext4_buffered_write_iter+0x22e/0x380 fs/ext4/file.c:269
ext4_file_write_iter+0x87c/0x1990
call_write_iter include/linux/fs.h:2101 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0xacf/0xe50 fs/read_write.c:594
ksys_write+0x1a2/0x2c0 fs/read_write.c:647
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+0x61/0xcb
RIP: 0033:0x7f16f38050f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f16f1d77168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f16f3924f80 RCX: 00007f16f38050f9
RDX: 0000000000000078 RSI: 0000000020001040 RDI: 0000000000000007
RBP: 00007f16f3860ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff2c7d13ff R14: 00007f16f1d77300 R15: 0000000000022000
</TASK>

syzbot

unread,
Apr 2, 2023, 11:04:38 PM4/2/23
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: 3b29299e5f60 Linux 6.1.22
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15c4ac7dc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a782518325cb082
dashboard link: https://syzkaller.appspot.com/bug?extid=2519f87e4f1b003aaba2
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11e15f85c80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=131c363ec80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f6cdeb0f8946/disk-3b29299e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cc5e0da6e9ab/vmlinux-3b29299e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e31f151a6a5/bzImage-3b29299e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e07fc2fef5d3/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2519f8...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): orphan cleanup on readonly fs
======================================================
WARNING: possible circular locking dependency detected
6.1.22-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor428/3773 is trying to acquire lock:
ffff888073785ae8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:479

but task is already holding lock:
ffff8880710720a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x999/0x1290 fs/ext4/inode.c:4267

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
ext4_map_blocks+0x38a/0x1ce0 fs/ext4/inode.c:574
ext4_getblk+0x1eb/0x7c0 fs/ext4/inode.c:864
ext4_bread+0x2a/0x170 fs/ext4/inode.c:920
ext4_quota_read+0x1a1/0x2c0 fs/ext4/super.c:7077
read_blk fs/quota/quota_tree.c:55 [inline]
find_tree_dqentry+0x190/0xc10 fs/quota/quota_tree.c:624
find_tree_dqentry+0x48a/0xc10 fs/quota/quota_tree.c:640
find_tree_dqentry+0x48a/0xc10 fs/quota/quota_tree.c:640
find_tree_dqentry+0x48a/0xc10 fs/quota/quota_tree.c:640
find_dqentry fs/quota/quota_tree.c:652 [inline]
qtree_read_dquot+0x13f/0x650 fs/quota/quota_tree.c:672
v2_read_dquot+0xbe/0x100 fs/quota/quota_v2.c:333
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6757
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x45e/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5531 [inline]
ext4_fill_super+0x83d1/0x8b20 fs/ext4/super.c:5659
get_tree_bdev+0x3fe/0x620 fs/super.c:1346
vfs_get_tree+0x88/0x270 fs/super.c:1553
do_new_mount+0x28b/0xad0 fs/namespace.c:3040
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
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

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6757
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5531 [inline]
ext4_fill_super+0x83d1/0x8b20 fs/ext4/super.c:5659
get_tree_bdev+0x3fe/0x620 fs/super.c:1346
vfs_get_tree+0x88/0x270 fs/super.c:1553
do_new_mount+0x28b/0xad0 fs/namespace.c:3040
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
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

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
__mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6741
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_free_space+0x992/0xfa0 fs/quota/dquot.c:1907
dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
dquot_free_space include/linux/quotaops.h:384 [inline]
dquot_free_block include/linux/quotaops.h:395 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6050 [inline]
ext4_free_blocks+0x1f05/0x2ee0 fs/ext4/mballoc.c:6179
ext4_remove_blocks fs/ext4/extents.c:2545 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2711 [inline]
ext4_ext_remove_space+0x22bb/0x4f30 fs/ext4/extents.c:2959
ext4_ext_truncate+0x172/0x210 fs/ext4/extents.c:4417
ext4_truncate+0xa1d/0x1290 fs/ext4/inode.c:4272
ext4_evict_inode+0xb68/0x1150 fs/ext4/inode.c:286
evict+0x2a4/0x620 fs/inode.c:664
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5531 [inline]
ext4_fill_super+0x83d1/0x8b20 fs/ext4/super.c:5659
get_tree_bdev+0x3fe/0x620 fs/super.c:1346
vfs_get_tree+0x88/0x270 fs/super.c:1553
do_new_mount+0x28b/0xad0 fs/namespace.c:3040
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
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

other info that might help us debug this:

Chain exists of:
&dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ei->i_data_sem/2);
lock(&s->s_dquot.dqio_sem);
lock(&ei->i_data_sem/2);
lock(&dquot->dq_lock);

*** DEADLOCK ***

4 locks held by syz-executor428/3773:
#0: ffff88802831c0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
#1: ffff88802831c650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1832 [inline]
#1: ffff88802831c650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1954 [inline]
#1: ffff88802831c650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x46d/0x1150 fs/ext4/inode.c:240
#2: ffff8880710720a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x999/0x1290 fs/ext4/inode.c:4267
#3: ffffffff8d06b248 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305

stack backtrace:
CPU: 0 PID: 3773 Comm: syz-executor428 Not tainted 6.1.22-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
__mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6741
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_free_space+0x992/0xfa0 fs/quota/dquot.c:1907
dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
dquot_free_space include/linux/quotaops.h:384 [inline]
dquot_free_block include/linux/quotaops.h:395 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6050 [inline]
ext4_free_blocks+0x1f05/0x2ee0 fs/ext4/mballoc.c:6179
ext4_remove_blocks fs/ext4/extents.c:2545 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2711 [inline]
ext4_ext_remove_space+0x22bb/0x4f30 fs/ext4/extents.c:2959
ext4_ext_truncate+0x172/0x210 fs/ext4/extents.c:4417
ext4_truncate+0xa1d/0x1290 fs/ext4/inode.c:4272
ext4_evict_inode+0xb68/0x1150 fs/ext4/inode.c:286
evict+0x2a4/0x620 fs/inode.c:664
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5531 [inline]
ext4_fill_super+0x83d1/0x8b20 fs/ext4/super.c:5659
get_tree_bdev+0x3fe/0x620 fs/super.c:1346
vfs_get_tree+0x88/0x270 fs/super.c:1553
do_new_mount+0x28b/0xad0 fs/namespace.c:3040
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
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: 0033:0x7f74b1034d3a
Code: 48 c7 c2 c0 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 a8 00 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbd0f1048 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000555556eae2c0 RCX: 00007f74b1034d3a
RDX: 0000000020000000 RSI: 0000000020000500 RDI: 00007fffbd0f1090
RBP: 0000000000000000 R08: 00007fffbd0f10d0 R09: 0000000000000007
R10: 0000000000000803 R11: 0000000000000202 R12: 0000000000000004
R13: 00007fffbd0f10d0 R14: 0000000000000003 R15: 00007fffbd0f1090
</TASK>
EXT4-fs error (device loop0): ext4_xattr_delete_inode:2926: inode #15: comm syz-executor428: corrupted xattr block 19
EXT4-fs warning (device loop0): ext4_evict_inode:299: xattr delete (err -117)
EXT4-fs (loop0): 1 orphan inode deleted

syzbot

unread,
May 7, 2023, 12:11:57 AM5/7/23
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: 8a7f2a5c5aa1 Linux 5.15.110
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17a3176a280000
kernel config: https://syzkaller.appspot.com/x/.config?x=ba8d5c9d6c5289f
dashboard link: https://syzkaller.appspot.com/bug?extid=dbab76e22a05c7efc6d6
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11c6e7d2280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1741fe4c280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fc04f54c047f/disk-8a7f2a5c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6b4ba4cb1191/vmlinux-8a7f2a5c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d927dc3f9670/bzImage-8a7f2a5c.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e51f0fd120e0/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dbab76...@syzkaller.appspotmail.com

EXT4-fs (loop0): Quota format mount options ignored when QUOTA feature is enabled
[EXT4 FS bs=4096, gc=1, bpg=95, ipg=32, mo=e842c118, mo2=0000]
System zones: 0-1, 18-18, 34-34, 40-40
EXT4-fs (loop0): orphan cleanup on readonly fs
EXT4-fs error (device loop0): mb_free_blocks:1830: group 0, inode 16: block 39:freeing already freed block (bit 39); block bitmap corrupt.
======================================================
WARNING: possible circular locking dependency detected
5.15.110-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor237/3652 is trying to acquire lock:
ffff8880719d7068 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:479

but task is already holding lock:
ffff8880719ea060 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x974/0x1130 fs/ext4/inode.c:4240

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
down_read+0x3b/0x50 kernel/locking/rwsem.c:1488
ext4_map_blocks+0x3a6/0x1e30 fs/ext4/inode.c:568
ext4_getblk+0x19f/0x710 fs/ext4/inode.c:856
ext4_bread+0x2a/0x170 fs/ext4/inode.c:909
ext4_quota_read+0x1a1/0x2c0 fs/ext4/super.c:6486
read_blk fs/quota/quota_tree.c:55 [inline]
find_tree_dqentry+0x192/0xb60 fs/quota/quota_tree.c:617
find_tree_dqentry+0x41a/0xb60 fs/quota/quota_tree.c:635
find_tree_dqentry+0x41a/0xb60 fs/quota/quota_tree.c:635
find_tree_dqentry+0x41a/0xb60 fs/quota/quota_tree.c:635
find_dqentry fs/quota/quota_tree.c:647 [inline]
qtree_read_dquot+0x13f/0x650 fs/quota/quota_tree.c:667
v2_read_dquot+0xbe/0x100 fs/quota/quota_v2.c:333
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6166
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xa0d/0x1290 fs/ext4/orphan.c:474
ext4_fill_super+0x9757/0x9f70 fs/ext4/super.c:4964
mount_bdev+0x26d/0x3a0 fs/super.c:1378
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1508
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
down_read+0x3b/0x50 kernel/locking/rwsem.c:1488
v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6166
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xa0d/0x1290 fs/ext4/orphan.c:474
ext4_fill_super+0x9757/0x9f70 fs/ext4/super.c:4964
mount_bdev+0x26d/0x3a0 fs/super.c:1378
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1508
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6150
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_free_space+0x992/0xfa0 fs/quota/dquot.c:1907
dquot_free_space_nodirty include/linux/quotaops.h:376 [inline]
dquot_free_space include/linux/quotaops.h:381 [inline]
dquot_free_block include/linux/quotaops.h:392 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6063 [inline]
ext4_free_blocks+0x1ec5/0x2d80 fs/ext4/mballoc.c:6192
ext4_remove_blocks fs/ext4/extents.c:2543 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2709 [inline]
ext4_ext_remove_space+0x24da/0x4db0 fs/ext4/extents.c:2957
ext4_ext_truncate+0x191/0x250 fs/ext4/extents.c:4419
ext4_truncate+0x9fd/0x1130 fs/ext4/inode.c:4245
ext4_evict_inode+0xba1/0x1100 fs/ext4/inode.c:289
evict+0x2a4/0x620 fs/inode.c:587
ext4_orphan_cleanup+0xa0d/0x1290 fs/ext4/orphan.c:474
ext4_fill_super+0x9757/0x9f70 fs/ext4/super.c:4964
mount_bdev+0x26d/0x3a0 fs/super.c:1378
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1508
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb

other info that might help us debug this:

Chain exists of:
&dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ei->i_data_sem/2);
lock(&s->s_dquot.dqio_sem);
lock(&ei->i_data_sem/2);
lock(&dquot->dq_lock);

*** DEADLOCK ***

4 locks held by syz-executor237/3652:
#0: ffff8880129960e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229
#1: ffff888012996650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1742 [inline]
#1: ffff888012996650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1859 [inline]
#1: ffff888012996650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x375/0x1100 fs/ext4/inode.c:243
#2: ffff8880719ea060 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x974/0x1130 fs/ext4/inode.c:4240
#3: ffffffff8ca3f238 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268

stack backtrace:
CPU: 1 PID: 3652 Comm: syz-executor237 Not tainted 5.15.110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6150
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_free_space+0x992/0xfa0 fs/quota/dquot.c:1907
dquot_free_space_nodirty include/linux/quotaops.h:376 [inline]
dquot_free_space include/linux/quotaops.h:381 [inline]
dquot_free_block include/linux/quotaops.h:392 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6063 [inline]
ext4_free_blocks+0x1ec5/0x2d80 fs/ext4/mballoc.c:6192
ext4_remove_blocks fs/ext4/extents.c:2543 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2709 [inline]
ext4_ext_remove_space+0x24da/0x4db0 fs/ext4/extents.c:2957
ext4_ext_truncate+0x191/0x250 fs/ext4/extents.c:4419
ext4_truncate+0x9fd/0x1130 fs/ext4/inode.c:4245
ext4_evict_inode+0xba1/0x1100 fs/ext4/inode.c:289
evict+0x2a4/0x620 fs/inode.c:587
ext4_orphan_cleanup+0xa0d/0x1290 fs/ext4/orphan.c:474
ext4_fill_super+0x9757/0x9f70 fs/ext4/super.c:4964
mount_bdev+0x26d/0x3a0 fs/super.c:1378
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1508
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb
RIP: 0033:0x7f0d4baadeca
Code: 48 c7 c2 c0 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 a8 00 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcabfc4768 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0d4baadeca
RDX: 0000000020000040 RSI: 0000000020000500 RDI: 00007ffcabfc4770
RBP: 00007ffcabfc4770 R08: 00007ffcabfc47b0 R09: 00007ffcabfc47c0
R10: 0000000002000281 R11: 0000000000000202 R12: 0000000000000004
R13: 0000555555f682c0 R14: 00007ffcabfc47b0 R15: 0000000000000000
</TASK>
EXT4-fs (loop0): 1 orphan inode deleted


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

syzbot

unread,
Aug 26, 2023, 12:58:25 AM8/26/23
to syzkaller...@googlegroups.com
syzbot suspects this issue could be fixed by backporting the following commit:

commit f0f44752f5f61ee4e3bd88ae033fdb888320aafe
git tree: upstream
Author: Boqun Feng <boqun...@gmail.com>
Date: Fri Jan 13 06:59:54 2023 +0000

rcu: Annotate SRCU's update-side lockdep dependencies

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1685e760680000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a782518325cb082
dashboard link: https://syzkaller.appspot.com/bug?extid=2519f87e4f1b003aaba2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11e15f85c80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=131c363ec80000


Please keep in mind that other backports might be required as well.

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

syzbot

unread,
Aug 29, 2023, 9:58:27 AM8/29/23
to nog...@google.com, syzkaller...@googlegroups.com
Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
possible deadlock in dquot_commit

loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): orphan cleanup on readonly fs
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc2-syzkaller-00857-gdf28e8690e71 #0 Not tainted
------------------------------------------------------
syz-executor.0/5845 is trying to acquire lock:
ffff888075339768 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:479

but task is already holding lock:
ffff88807018a0a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x97d/0x1150 fs/ext4/inode.c:4337

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
lock_acquire+0x1dd/0x520 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
ext4_map_blocks+0x38a/0x1ce0 fs/ext4/inode.c:574
ext4_getblk+0x1eb/0x7c0 fs/ext4/inode.c:863
ext4_bread+0x2a/0x170 fs/ext4/inode.c:919
ext4_quota_write+0x21e/0x570 fs/ext4/super.c:7135
write_blk fs/quota/quota_tree.c:64 [inline]
get_free_dqblk+0x336/0x690 fs/quota/quota_tree.c:130
do_insert_tree+0x261/0x1a50 fs/quota/quota_tree.c:340
do_insert_tree+0x70b/0x1a50 fs/quota/quota_tree.c:375
dq_insert_tree fs/quota/quota_tree.c:401 [inline]
qtree_write_dquot+0x3b9/0x530 fs/quota/quota_tree.c:420
v2_write_dquot+0x11c/0x190 fs/quota/quota_v2.c:358
dquot_acquire+0x34d/0x680 fs/quota/dquot.c:444
ext4_acquire_dquot+0x2e2/0x400 fs/ext4/super.c:6770
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5509 [inline]
ext4_fill_super+0x8235/0x8990 fs/ext4/super.c:5637
get_tree_bdev+0x3fe/0x620 fs/super.c:1294
vfs_get_tree+0x88/0x270 fs/super.c:1501
do_new_mount+0x28b/0xad0 fs/namespace.c:3042
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3571
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

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
lock_acquire+0x1dd/0x520 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
dquot_acquire+0x188/0x680 fs/quota/dquot.c:435
ext4_acquire_dquot+0x2e2/0x400 fs/ext4/super.c:6770
dqget+0x98b/0xdb0 fs/quota/dquot.c:914
__dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5509 [inline]
ext4_fill_super+0x8235/0x8990 fs/ext4/super.c:5637
get_tree_bdev+0x3fe/0x620 fs/super.c:1294
vfs_get_tree+0x88/0x270 fs/super.c:1501
do_new_mount+0x28b/0xad0 fs/namespace.c:3042
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3571
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

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1dd/0x520 kernel/locking/lockdep.c:5669
__mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1ee/0x2b0 fs/ext4/super.c:6754
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_free_space+0x9a0/0xfc0 fs/quota/dquot.c:1907
dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
dquot_free_space include/linux/quotaops.h:384 [inline]
dquot_free_block include/linux/quotaops.h:395 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6044 [inline]
ext4_free_blocks+0x1e9f/0x2dc0 fs/ext4/mballoc.c:6173
ext4_remove_blocks fs/ext4/extents.c:2545 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
ext4_ext_remove_space+0x216a/0x4d70 fs/ext4/extents.c:2958
ext4_ext_truncate+0x172/0x210 fs/ext4/extents.c:4416
ext4_truncate+0xa06/0x1150 fs/ext4/inode.c:4342
ext4_evict_inode+0xb8a/0x10f0 fs/ext4/inode.c:286
evict+0x2a4/0x620 fs/inode.c:665
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5509 [inline]
ext4_fill_super+0x8235/0x8990 fs/ext4/super.c:5637
get_tree_bdev+0x3fe/0x620 fs/super.c:1294
vfs_get_tree+0x88/0x270 fs/super.c:1501
do_new_mount+0x28b/0xad0 fs/namespace.c:3042
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3571
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

other info that might help us debug this:

Chain exists of:
&dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ei->i_data_sem/2);
lock(&s->s_dquot.dqio_sem);
lock(&ei->i_data_sem/2);
lock(&dquot->dq_lock);

*** DEADLOCK ***

4 locks held by syz-executor.0/5845:
#0: ffff88802377a0e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
#1: ffff88802377a650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1477 [inline]
#1: ffff88802377a650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1599 [inline]
#1: ffff88802377a650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x457/0x10f0 fs/ext4/inode.c:240
#2: ffff88807018a0a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x97d/0x1150 fs/ext4/inode.c:4337
#3: ffffffff8d26b348 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:326

stack backtrace:
CPU: 0 PID: 5845 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00857-gdf28e8690e71 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1dd/0x520 kernel/locking/lockdep.c:5669
__mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
dquot_commit+0x57/0x510 fs/quota/dquot.c:479
ext4_write_dquot+0x1ee/0x2b0 fs/ext4/super.c:6754
mark_dquot_dirty fs/quota/dquot.c:346 [inline]
mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
__dquot_free_space+0x9a0/0xfc0 fs/quota/dquot.c:1907
dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
dquot_free_space include/linux/quotaops.h:384 [inline]
dquot_free_block include/linux/quotaops.h:395 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6044 [inline]
ext4_free_blocks+0x1e9f/0x2dc0 fs/ext4/mballoc.c:6173
ext4_remove_blocks fs/ext4/extents.c:2545 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
ext4_ext_remove_space+0x216a/0x4d70 fs/ext4/extents.c:2958
ext4_ext_truncate+0x172/0x210 fs/ext4/extents.c:4416
ext4_truncate+0xa06/0x1150 fs/ext4/inode.c:4342
ext4_evict_inode+0xb8a/0x10f0 fs/ext4/inode.c:286
evict+0x2a4/0x620 fs/inode.c:665
ext4_orphan_cleanup+0xb1d/0x13c0 fs/ext4/orphan.c:474
__ext4_fill_super fs/ext4/super.c:5509 [inline]
ext4_fill_super+0x8235/0x8990 fs/ext4/super.c:5637
get_tree_bdev+0x3fe/0x620 fs/super.c:1294
vfs_get_tree+0x88/0x270 fs/super.c:1501
do_new_mount+0x28b/0xad0 fs/namespace.c:3042
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3571
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: 0033:0x7f50d647e05a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f50d715dee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f50d715df80 RCX: 00007f50d647e05a
RDX: 0000000020000040 RSI: 0000000020000500 RDI: 00007f50d715df40
RBP: 0000000020000040 R08: 00007f50d715df80 R09: 0000000000004509
R10: 0000000000004509 R11: 0000000000000246 R12: 0000000020000500
R13: 00007f50d715df40 R14: 00000000000004b4 R15: 000000000000002c
</TASK>
EXT4-fs (loop0): 1 orphan inode deleted


Tested on:

commit: df28e869 Merge branch 'net-better-const'
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=143ab3bba80000
kernel config: https://syzkaller.appspot.com/x/.config?x=99cdf1fc822bd223
dashboard link: https://syzkaller.appspot.com/bug?extid=2519f87e4f1b003aaba2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.

syzbot

unread,
Oct 25, 2023, 12:19:34 PM10/25/23
to syzkaller...@googlegroups.com
syzbot suspects this issue could be fixed by backporting the following commit:

commit f0f44752f5f61ee4e3bd88ae033fdb888320aafe
git tree: upstream
Author: Boqun Feng <boqun...@gmail.com>
Date: Fri Jan 13 06:59:54 2023 +0000

rcu: Annotate SRCU's update-side lockdep dependencies

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1346f643680000
kernel config: https://syzkaller.appspot.com/x/.config?x=ba8d5c9d6c5289f
dashboard link: https://syzkaller.appspot.com/bug?extid=dbab76e22a05c7efc6d6
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11c6e7d2280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1741fe4c280000


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