[v5.15] possible deadlock in hfsplus_file_truncate

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syzbot

unread,

Mar 11, 2023, 2:42:45 PM3/11/23

to syzkaller...@googlegroups.com

Hello,

syzbot found the following issue on:

HEAD commit: d214f240b0f6 Linux 5.15.100
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13bd5a1ac80000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5c5a36ceb954515
dashboard link: https://syzkaller.appspot.com/bug?extid=c9d1923ec3044ae3609c
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/4e12037285d4/disk-d214f240.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/929d982226d5/vmlinux-d214f240.xz
kernel image: https://storage.googleapis.com/syzbot-assets/59140c032c99/bzImage-d214f240.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c9d192...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.15.100-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/10642 is trying to acquire lock:
ffff88807e2380b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x864/0xb80 fs/hfsplus/extents.c:595

but task is already holding lock:
ffff8880667f07c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2e1/0xb80 fs/hfsplus/extents.c:576

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
lock_acquire+0x1ff/0x570 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
hfsplus_get_block+0x37f/0x14e0 fs/hfsplus/extents.c:260
block_read_full_page+0x2f9/0xde0 fs/buffer.c:2290
do_read_cache_page+0x752/0x1040
read_mapping_page include/linux/pagemap.h:515 [inline]
__hfs_bnode_create+0x4f2/0xbb0 fs/hfsplus/bnode.c:447
hfsplus_bnode_find+0x22e/0xe80 fs/hfsplus/bnode.c:497
hfsplus_brec_find+0x17f/0x570 fs/hfsplus/bfind.c:183
hfsplus_brec_read+0x27/0x100 fs/hfsplus/bfind.c:222
hfsplus_find_cat+0x17b/0x5c0 fs/hfsplus/catalog.c:202
hfsplus_iget+0x403/0x640 fs/hfsplus/super.c:82
hfsplus_fill_super+0xca4/0x1c90 fs/hfsplus/super.c:503
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 (&tree->tree_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+0x1ff/0x570 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
hfsplus_file_truncate+0x864/0xb80 fs/hfsplus/extents.c:595
hfsplus_setattr+0x1b9/0x280 fs/hfsplus/inode.c:267
notify_change+0xdad/0x1060 fs/attr.c:426
do_truncate+0x217/0x300 fs/open.c:65
handle_truncate fs/namei.c:3136 [inline]
do_open fs/namei.c:3484 [inline]
path_openat+0x2866/0x2ee0 fs/namei.c:3615
do_filp_open+0x21c/0x460 fs/namei.c:3642
do_sys_openat2+0x13b/0x500 fs/open.c:1211
do_sys_open fs/open.c:1227 [inline]
__do_sys_creat fs/open.c:1301 [inline]
__se_sys_creat fs/open.c:1295 [inline]
__x64_sys_creat+0x11f/0x160 fs/open.c:1295
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:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock);
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock);

*** DEADLOCK ***

3 locks held by syz-executor.2/10642:
#0: ffff88807b848460 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
#1: ffff8880667f09c0 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#1: ffff8880667f09c0 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: do_truncate+0x203/0x300 fs/open.c:63
#2: ffff8880667f07c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2e1/0xb80 fs/hfsplus/extents.c:576

stack backtrace:
CPU: 0 PID: 10642 Comm: syz-executor.2 Not tainted 5.15.100-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+0x1ff/0x570 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
hfsplus_file_truncate+0x864/0xb80 fs/hfsplus/extents.c:595
hfsplus_setattr+0x1b9/0x280 fs/hfsplus/inode.c:267
notify_change+0xdad/0x1060 fs/attr.c:426
do_truncate+0x217/0x300 fs/open.c:65
handle_truncate fs/namei.c:3136 [inline]
do_open fs/namei.c:3484 [inline]
path_openat+0x2866/0x2ee0 fs/namei.c:3615
do_filp_open+0x21c/0x460 fs/namei.c:3642
do_sys_openat2+0x13b/0x500 fs/open.c:1211
do_sys_open fs/open.c:1227 [inline]
__do_sys_creat fs/open.c:1301 [inline]
__se_sys_creat fs/open.c:1295 [inline]
__x64_sys_creat+0x11f/0x160 fs/open.c:1295
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: 0033:0x7fe1c6d9b0f9
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:00007fe1c530d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fe1c6ebaf80 RCX: 00007fe1c6d9b0f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000700
RBP: 00007fe1c6df6ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffca42ca98f R14: 00007fe1c530d300 R15: 0000000000022000
</TASK>

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

syzbot

unread,

Mar 15, 2023, 7:18:57 AM3/15/23

to syzkaller...@googlegroups.com

Hello,

syzbot found the following issue on:

HEAD commit: 6449a0ba6843 Linux 6.1.19
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=154b8aecc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=75eadb21ef1208e4
dashboard link: https://syzkaller.appspot.com/bug?extid=9d8847efe150ee2e2bcb

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/dc227ecd3e21/disk-6449a0ba.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d08e21b50c2/vmlinux-6449a0ba.xz
kernel image: https://storage.googleapis.com/syzbot-assets/71a43f2c4d2c/Image-6449a0ba.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+9d8847...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected

6.1.19-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/13929 is trying to acquire lock:
ffff0000d36680b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x6d0/0x9b8 fs/hfsplus/extents.c:595

but task is already holding lock:

ffff00010c8473c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x250/0x9b8 fs/hfsplus/extents.c:576

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
__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
hfsplus_file_extend+0x198/0x14cc fs/hfsplus/extents.c:457
hfsplus_bmap_reserve+0xec/0x474 fs/hfsplus/btree.c:358
hfsplus_create_attr+0x1b0/0x568 fs/hfsplus/attributes.c:221
__hfsplus_setxattr+0x990/0x1d10 fs/hfsplus/xattr.c:354
hfsplus_setxattr+0xb4/0xec fs/hfsplus/xattr.c:434
hfsplus_user_setxattr+0x54/0x6c fs/hfsplus/xattr_user.c:30
__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

-> #1 (&tree->tree_lock/2){+.+.}-{3:3}:
__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
hfsplus_find_init+0x144/0x1bc
hfsplus_attr_exists+0xf8/0x1c8 fs/hfsplus/attributes.c:178
__hfsplus_setxattr+0x384/0x1d10 fs/hfsplus/xattr.c:336
hfsplus_setxattr+0xb4/0xec fs/hfsplus/xattr.c:434
hfsplus_user_setxattr+0x54/0x6c fs/hfsplus/xattr_user.c:30
__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 (&tree->tree_lock){+.+.}-{3:3}:

check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
lock_acquire+0x300/0x8e4 kernel/locking/lockdep.c:5669
__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
hfsplus_file_truncate+0x6d0/0x9b8 fs/hfsplus/extents.c:595
hfsplus_write_failed+0x88/0xa4 fs/hfsplus/inode.c:42
hfsplus_write_begin+0xe0/0xe4 fs/hfsplus/inode.c:56
generic_perform_write+0x278/0x55c mm/filemap.c:3754
__generic_file_write_iter+0x168/0x388 mm/filemap.c:3882
generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:3914
call_write_iter include/linux/fs.h:2205 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x610/0x914 fs/read_write.c:584
ksys_write+0x15c/0x26c fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__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:
&tree->tree_lock --> &tree->tree_lock/2 --> &HFSPLUS_I(inode)->extents_lock

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&HFSPLUS_I(inode)->extents_lock);

lock(&tree->tree_lock/2);

lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock);

*** DEADLOCK ***

4 locks held by syz-executor.3/13929:
#0: ffff0000c95700e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xd8/0x104 fs/file.c:1046
#1: ffff0000dc268460 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x244/0x914 fs/read_write.c:580
#2: ffff00010c8475c0 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
#2: ffff00010c8475c0 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: generic_file_write_iter+0x88/0x2b4 mm/filemap.c:3911
#3: ffff00010c8473c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x250/0x9b8 fs/hfsplus/extents.c:576

stack backtrace:
CPU: 1 PID: 13929 Comm: syz-executor.3 Not tainted 6.1.19-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/0x5c lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056
check_noncircular+0x2cc/0x378 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 kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
lock_acquire+0x300/0x8e4 kernel/locking/lockdep.c:5669
__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
hfsplus_file_truncate+0x6d0/0x9b8 fs/hfsplus/extents.c:595
hfsplus_write_failed+0x88/0xa4 fs/hfsplus/inode.c:42
hfsplus_write_begin+0xe0/0xe4 fs/hfsplus/inode.c:56
generic_perform_write+0x278/0x55c mm/filemap.c:3754
__generic_file_write_iter+0x168/0x388 mm/filemap.c:3882
generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:3914
call_write_iter include/linux/fs.h:2205 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x610/0x914 fs/read_write.c:584
ksys_write+0x15c/0x26c fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__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

syzbot

unread,

Jun 4, 2023, 1:07:17 PM6/4/23

to syzkaller...@googlegroups.com

syzbot has found a reproducer for the following issue on:

HEAD commit: 0ab06468cbd1 Linux 5.15.114
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=171795a5280000
kernel config: https://syzkaller.appspot.com/x/.config?x=9a2696a271d0eba

dashboard link: https://syzkaller.appspot.com/bug?extid=c9d1923ec3044ae3609c
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15aebb0b280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10615679280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8ff3613d3f6b/disk-0ab06468.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eebe2d8c6813/vmlinux-0ab06468.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f30284c26197/Image-0ab06468.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/d12f0689ad7b/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c9d192...@syzkaller.appspotmail.com

option from the mount to silence this warning.
=======================================================

======================================================
WARNING: possible circular locking dependency detected

5.15.114-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor224/3960 is trying to acquire lock:
ffff0000c8c640b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x6d4/0x9cc fs/hfsplus/extents.c:595

but task is already holding lock:

ffff0000c92b2988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x254/0x9cc fs/hfsplus/extents.c:576

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:

__mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
hfsplus_file_extend+0x198/0x14e0 fs/hfsplus/extents.c:457
hfsplus_bmap_reserve+0xec/0x474 fs/hfsplus/btree.c:357
hfsplus_create_cat+0x18c/0x1330 fs/hfsplus/catalog.c:272
hfsplus_fill_super+0xf64/0x167c fs/hfsplus/super.c:560
mount_bdev+0x274/0x370 fs/super.c:1378
hfsplus_mount+0x44/0x58 fs/hfsplus/super.c:641
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610
vfs_get_tree+0x90/0x274 fs/super.c:1508
do_new_mount+0x25c/0x8c4 fs/namespace.c:2994
path_mount+0x590/0x104c fs/namespace.c:3324

do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]

__se_sys_mount fs/namespace.c:3522 [inline]
__arm64_sys_mount+0x510/0x5e0 fs/namespace.c:3522
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0 (&tree->tree_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]

validate_chain kernel/locking/lockdep.c:3787 [inline]
__lock_acquire+0x32cc/0x7620 kernel/locking/lockdep.c:5011
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622
__mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
hfsplus_file_truncate+0x6d4/0x9cc fs/hfsplus/extents.c:595
hfsplus_setattr+0x18c/0x25c fs/hfsplus/inode.c:267
notify_change+0xac4/0xd60 fs/attr.c:488
do_truncate+0x1c0/0x28c fs/open.c:65
vfs_truncate+0x2e0/0x388 fs/open.c:111
do_sys_truncate+0xec/0x1b4 fs/open.c:134
__do_sys_truncate fs/open.c:146 [inline]
__se_sys_truncate fs/open.c:144 [inline]
__arm64_sys_truncate+0x5c/0x70 fs/open.c:144
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock);
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock);

*** DEADLOCK ***

3 locks held by syz-executor224/3960:
#0: ffff0000c8c62460 (sb_writers#8){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
#1: ffff0000c92b2b80 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#1: ffff0000c92b2b80 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: do_truncate+0x1ac/0x28c fs/open.c:63
#2: ffff0000c92b2988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x254/0x9cc fs/hfsplus/extents.c:576

stack backtrace:
CPU: 1 PID: 3960 Comm: syz-executor224 Not tainted 5.15.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216

__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:2011
check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133

check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]

syzbot

unread,

Jun 4, 2023, 1:51:51 PM6/4/23

to syzkaller...@googlegroups.com

syzbot has found a reproducer for the following issue on:

HEAD commit: d2869ace6eeb Linux 6.1.31
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1633b42d280000
kernel config: https://syzkaller.appspot.com/x/.config?x=11263f470b7a4c92

dashboard link: https://syzkaller.appspot.com/bug?extid=9d8847efe150ee2e2bcb
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16663c2d280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=121b802d280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b17a7cd87498/disk-d2869ace.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cc8291ae723a/vmlinux-d2869ace.xz
kernel image: https://storage.googleapis.com/syzbot-assets/04943541fc25/Image-d2869ace.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/524403207aa5/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9d8847...@syzkaller.appspotmail.com

option from the mount to silence this warning.
=======================================================

======================================================
WARNING: possible circular locking dependency detected

6.1.31-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor200/4221 is trying to acquire lock:
ffff0000d81140b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x6d0/0x9b8 fs/hfsplus/extents.c:595

but task is already holding lock:

ffff0000d768a988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x250/0x9b8 fs/hfsplus/extents.c:576

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:

__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
hfsplus_file_extend+0x198/0x14cc fs/hfsplus/extents.c:457
hfsplus_bmap_reserve+0xec/0x474 fs/hfsplus/btree.c:358

hfsplus_create_cat+0x18c/0x1330 fs/hfsplus/catalog.c:272
hfsplus_fill_super+0xf60/0x166c fs/hfsplus/super.c:560
mount_bdev+0x274/0x370 fs/super.c:1423

hfsplus_mount+0x44/0x58 fs/hfsplus/super.c:641
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610

vfs_get_tree+0x90/0x274 fs/super.c:1553
do_new_mount+0x25c/0x8c4 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

-> #0 (&tree->tree_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056

lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669

hfsplus_setattr+0x18c/0x25c fs/hfsplus/inode.c:269
notify_change+0xc24/0xec0 fs/attr.c:482
do_truncate+0x1c0/0x28c fs/open.c:65
vfs_truncate+0x2c4/0x36c fs/open.c:111

do_sys_truncate+0xec/0x1b4 fs/open.c:134
__do_sys_truncate fs/open.c:146 [inline]
__se_sys_truncate fs/open.c:144 [inline]
__arm64_sys_truncate+0x5c/0x70 fs/open.c:144

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&HFSPLUS_I(inode)->extents_lock);

lock(&tree->tree_lock);

lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock);

*** DEADLOCK ***

3 locks held by syz-executor200/4221:
#0: ffff0000d8012460 (sb_writers#8){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
#1: ffff0000d768ab80 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
#1: ffff0000d768ab80 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: do_truncate+0x1ac/0x28c fs/open.c:63
#2: ffff0000d768a988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x250/0x9b8 fs/hfsplus/extents.c:576

stack backtrace:
CPU: 1 PID: 4221 Comm: syz-executor200 Not tainted 6.1.31-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023

dump_stack+0x1c/0x58 lib/dump_stack.c:113

print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056
check_noncircular+0x2cc/0x378 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 kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056

lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669

hfsplus_setattr+0x18c/0x25c fs/hfsplus/inode.c:269
notify_change+0xc24/0xec0 fs/attr.c:482
do_truncate+0x1c0/0x28c fs/open.c:65
vfs_truncate+0x2c4/0x36c fs/open.c:111

do_sys_truncate+0xec/0x1b4 fs/open.c:134
__do_sys_truncate fs/open.c:146 [inline]
__se_sys_truncate fs/open.c:144 [inline]
__arm64_sys_truncate+0x5c/0x70 fs/open.c:144

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