[syzbot] [ocfs2?] possible deadlock in ocfs2_calc_xattr_init

From: syzbot
Date: Thu Oct 03 2024 - 21:35:43 EST

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Hello,

syzbot found the following issue on:

HEAD commit: e7ed34365879 Merge tag 'mailbox-v6.12' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1000c127980000
kernel config: https://syzkaller.appspot.com/x/.config?x=bf263a6a5debbeef
dashboard link: https://syzkaller.appspot.com/bug?extid=6f7edba4b1e2ca109d7f
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74f7ccd405cc/disk-e7ed3436.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ef3b18bc5269/vmlinux-e7ed3436.xz
kernel image: https://storage.googleapis.com/syzbot-assets/54ef06c52fbb/bzImage-e7ed3436.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6f7edba4b1e2ca109d7f@xxxxxxxxxxxxxxxxxxxxxxxxx

======================================================
WARNING: possible circular locking dependency detected
6.11.0-syzkaller-12113-ge7ed34365879 #0 Not tainted
------------------------------------------------------
syz.0.131/5956 is trying to acquire lock:
ffff888051572378 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_calc_xattr_init+0x5e7/0xcc0 fs/ocfs2/xattr.c:627

but task is already holding lock:
ffff8880542c5f40 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
ffff8880542c5f40 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x11d/0x4940 fs/ocfs2/suballoc.c:786

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}:
down_write+0x93/0x200 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:815 [inline]
ocfs2_remove_inode+0x15c/0x8a0 fs/ocfs2/inode.c:655
ocfs2_wipe_inode+0x455/0x1220 fs/ocfs2/inode.c:818
ocfs2_delete_inode fs/ocfs2/inode.c:1079 [inline]
ocfs2_evict_inode+0x6c5/0x15d0 fs/ocfs2/inode.c:1216
evict+0x40c/0x970 fs/inode.c:723
iput_final fs/inode.c:1875 [inline]
iput fs/inode.c:1901 [inline]
iput+0x530/0x890 fs/inode.c:1887
ocfs2_dentry_iput+0x13a/0x340 fs/ocfs2/dcache.c:411
dentry_unlink_inode+0x282/0x480 fs/dcache.c:410
__dentry_kill+0x1d0/0x600 fs/dcache.c:615
dput.part.0+0x4b1/0x9b0 fs/dcache.c:857
dput+0x1f/0x30 fs/dcache.c:847
ovl_check_rename_whiteout fs/overlayfs/super.c:586 [inline]
ovl_make_workdir fs/overlayfs/super.c:685 [inline]
ovl_get_workdir fs/overlayfs/super.c:808 [inline]
ovl_fill_super+0x1300/0x6720 fs/overlayfs/super.c:1376
vfs_get_super fs/super.c:1280 [inline]
get_tree_nodev+0xdd/0x190 fs/super.c:1299
vfs_get_tree+0x92/0x380 fs/super.c:1800
do_new_mount fs/namespace.c:3507 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4055 [inline]
__se_sys_mount fs/namespace.c:4032 [inline]
__x64_sys_mount+0x294/0x320 fs/namespace.c:4032
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}:
down_write+0x93/0x200 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:815 [inline]
ocfs2_del_inode_from_orphan+0x112/0x700 fs/ocfs2/namei.c:2726
ocfs2_dio_end_io_write+0x2cc/0xf30 fs/ocfs2/aops.c:2329
ocfs2_dio_end_io+0x139/0x2a0 fs/ocfs2/aops.c:2427
dio_complete+0x21b/0x8e0 fs/direct-io.c:281
__blockdev_direct_IO+0x3139/0x3d10 fs/direct-io.c:1303
ocfs2_direct_IO+0x263/0x360 fs/ocfs2/aops.c:2464
generic_file_direct_write+0x19a/0x410 mm/filemap.c:3977
__generic_file_write_iter+0x11b/0x240 mm/filemap.c:4141
ocfs2_file_write_iter+0xb70/0x20e0 fs/ocfs2/file.c:2456
do_iter_readv_writev+0x535/0x7f0 fs/read_write.c:834
vfs_writev+0x363/0xdd0 fs/read_write.c:1064
do_pwritev+0x1b4/0x270 fs/read_write.c:1165
__do_sys_pwritev2 fs/read_write.c:1224 [inline]
__se_sys_pwritev2 fs/read_write.c:1215 [inline]
__x64_sys_pwritev2+0xef/0x160 fs/read_write.c:1215
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&oi->ip_alloc_sem){++++}-{3:3}:
down_write+0x93/0x200 kernel/locking/rwsem.c:1577
ocfs2_try_remove_refcount_tree+0xa8/0x320 fs/ocfs2/refcounttree.c:932
ocfs2_xattr_set+0x103c/0x2a30 fs/ocfs2/xattr.c:3670
__vfs_removexattr+0x156/0x1c0 fs/xattr.c:518
__vfs_removexattr_locked+0x166/0x480 fs/xattr.c:553
vfs_removexattr+0xcf/0x270 fs/xattr.c:575
ovl_do_removexattr fs/overlayfs/overlayfs.h:332 [inline]
ovl_removexattr fs/overlayfs/overlayfs.h:340 [inline]
ovl_make_workdir fs/overlayfs/super.c:728 [inline]
ovl_get_workdir fs/overlayfs/super.c:808 [inline]
ovl_fill_super+0x4fb3/0x6720 fs/overlayfs/super.c:1376
vfs_get_super fs/super.c:1280 [inline]
get_tree_nodev+0xdd/0x190 fs/super.c:1299
vfs_get_tree+0x92/0x380 fs/super.c:1800
do_new_mount fs/namespace.c:3507 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4055 [inline]
__se_sys_mount fs/namespace.c:4032 [inline]
__x64_sys_mount+0x294/0x320 fs/namespace.c:4032
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&oi->ip_xattr_sem){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
ocfs2_calc_xattr_init+0x5e7/0xcc0 fs/ocfs2/xattr.c:627
ocfs2_mknod+0x9f2/0x2440 fs/ocfs2/namei.c:328
ocfs2_create+0x185/0x450 fs/ocfs2/namei.c:672
vfs_create fs/namei.c:3294 [inline]
vfs_create+0x4c5/0x770 fs/namei.c:3278
do_mknodat+0x3d5/0x5d0 fs/namei.c:4185
__do_sys_mknod fs/namei.c:4218 [inline]
__se_sys_mknod fs/namei.c:4216 [inline]
__x64_sys_mknod+0x87/0xb0 fs/namei.c:4216
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
&oi->ip_xattr_sem --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type] --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);
rlock(&oi->ip_xattr_sem);

*** DEADLOCK ***

3 locks held by syz.0.131/5956:
#0: ffff88807f8de420 (sb_writers#19){.+.+}-{0:0}, at: filename_create+0x10d/0x530 fs/namei.c:4019
#1: ffff888051572640 (&type->i_mutex_dir_key#13/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
#1: ffff888051572640 (&type->i_mutex_dir_key#13/1){+.+.}-{3:3}, at: filename_create+0x1c2/0x530 fs/namei.c:4026
#2: ffff8880542c5f40 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
#2: ffff8880542c5f40 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x11d/0x4940 fs/ocfs2/suballoc.c:786

stack backtrace:
CPU: 1 UID: 0 PID: 5956 Comm: syz.0.131 Not tainted 6.11.0-syzkaller-12113-ge7ed34365879 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
ocfs2_calc_xattr_init+0x5e7/0xcc0 fs/ocfs2/xattr.c:627
ocfs2_mknod+0x9f2/0x2440 fs/ocfs2/namei.c:328
ocfs2_create+0x185/0x450 fs/ocfs2/namei.c:672
vfs_create fs/namei.c:3294 [inline]
vfs_create+0x4c5/0x770 fs/namei.c:3278
do_mknodat+0x3d5/0x5d0 fs/namei.c:4185
__do_sys_mknod fs/namei.c:4218 [inline]
__se_sys_mknod fs/namei.c:4216 [inline]
__x64_sys_mknod+0x87/0xb0 fs/namei.c:4216
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c6537dff9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9c661e3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f9c65535f80 RCX: 00007f9c6537dff9
RDX: 0000000000000701 RSI: 0000000000000800 RDI: 0000000020000500
RBP: 00007f9c653f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9c65535f80 R15: 00007ffcd340d568
</TASK>

---
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Next message: Mathieu Desnoyers: "Re: [PATCH v1 1/8] tracing: Declare system call tracepoints with TRACE_EVENT_SYSCALL"
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