Re: [syzbot] [ocfs2?] possible deadlock in ocfs2_write_begin_nolock

From: syzbot
Date: Thu Sep 12 2024 - 16:21:39 EST

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In reply to: syzbot: "[syzbot] [ocfs2?] possible deadlock in ocfs2_write_begin_nolock"
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syzbot has found a reproducer for the following issue on:

HEAD commit: 77f587896757 Merge tag 'arm-fixes-6.11-3' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f960a9980000
kernel config: https://syzkaller.appspot.com/x/.config?x=61d235cb8d15001c
dashboard link: https://syzkaller.appspot.com/bug?extid=cf0ed67a79e4fadd9f91
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17343807980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1325149f980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-77f58789.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/984b5a502ad8/vmlinux-77f58789.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4bea7acc421c/bzImage-77f58789.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/a71deb151482/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cf0ed67a79e4fadd9f91@xxxxxxxxxxxxxxxxxxxxxxxxx

=======================================================
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc7-syzkaller-00039-g77f587896757 #0 Not tainted
------------------------------------------------------
syz-executor271/5102 is trying to acquire lock:
ffff88804048a610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_write_begin_inline fs/ocfs2/aops.c:1480 [inline]
ffff88804048a610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1583 [inline]
ffff88804048a610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_write_begin_nolock+0x226b/0x4d30 fs/ocfs2/aops.c:1669

but task is already holding lock:
ffff888041fdcda0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_write_begin+0x1d1/0x3a0 fs/ocfs2/aops.c:1901

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (&oi->ip_alloc_sem){++++}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_write+0x99/0x220 kernel/locking/rwsem.c:1579
ocfs2_try_remove_refcount_tree+0xb6/0x330 fs/ocfs2/refcounttree.c:931
ocfs2_xattr_set+0xa4f/0x1930 fs/ocfs2/xattr.c:3670
ocfs2_set_acl+0x4cb/0x580 fs/ocfs2/acl.c:254
ocfs2_iop_set_acl+0x24a/0x3c0 fs/ocfs2/acl.c:286
set_posix_acl fs/posix_acl.c:955 [inline]
vfs_set_acl+0x7fd/0xa60 fs/posix_acl.c:1134
do_setxattr fs/xattr.c:626 [inline]
path_setxattr+0x3bd/0x4d0 fs/xattr.c:658
__do_sys_lsetxattr fs/xattr.c:683 [inline]
__se_sys_lsetxattr fs/xattr.c:679 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:679
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (&oi->ip_xattr_sem){++++}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
ocfs2_init_acl+0x397/0x930 fs/ocfs2/acl.c:366
ocfs2_mknod+0x1c05/0x2b40 fs/ocfs2/namei.c:408
ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
do_mkdirat+0x264/0x3a0 fs/namei.c:4233
__do_sys_mkdirat fs/namei.c:4248 [inline]
__se_sys_mkdirat fs/namei.c:4246 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (jbd2_handle){++++}-{0:0}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
start_this_handle+0x1eb4/0x2110 fs/jbd2/transaction.c:448
jbd2__journal_start+0x2da/0x5d0 fs/jbd2/transaction.c:505
jbd2_journal_start+0x29/0x40 fs/jbd2/transaction.c:544
ocfs2_start_trans+0x3c9/0x700 fs/ocfs2/journal.c:352
ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
do_mkdirat+0x264/0x3a0 fs/namei.c:4233
__do_sys_mkdirat fs/namei.c:4248 [inline]
__se_sys_mkdirat fs/namei.c:4246 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&journal->j_trans_barrier){.+.+}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
do_mkdirat+0x264/0x3a0 fs/namei.c:4233
__do_sys_mkdirat fs/namei.c:4248 [inline]
__se_sys_mkdirat fs/namei.c:4246 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (sb_internal#2){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1676 [inline]
sb_start_intwrite include/linux/fs.h:1859 [inline]
ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
ocfs2_write_begin_inline fs/ocfs2/aops.c:1480 [inline]
ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1583 [inline]
ocfs2_write_begin_nolock+0x226b/0x4d30 fs/ocfs2/aops.c:1669
ocfs2_write_begin+0x205/0x3a0 fs/ocfs2/aops.c:1903
generic_perform_write+0x399/0x840 mm/filemap.c:4019
ocfs2_file_write_iter+0x17b4/0x1f60 fs/ocfs2/file.c:2455
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xa72/0xc90 fs/read_write.c:590
ksys_write+0x1a0/0x2c0 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
sb_internal#2 --> &oi->ip_xattr_sem --> &oi->ip_alloc_sem

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&oi->ip_alloc_sem);
lock(&oi->ip_xattr_sem);
lock(&oi->ip_alloc_sem);
rlock(sb_internal#2);

*** DEADLOCK ***

3 locks held by syz-executor271/5102:
#0: ffff88804048a420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2882 [inline]
#0: ffff88804048a420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586
#1: ffff888041fdd100 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline]
#1: ffff888041fdd100 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x46a/0x1f60 fs/ocfs2/file.c:2387
#2: ffff888041fdcda0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_write_begin+0x1d1/0x3a0 fs/ocfs2/aops.c:1901

stack backtrace:
CPU: 0 UID: 0 PID: 5102 Comm: syz-executor271 Not tainted 6.11.0-rc7-syzkaller-00039-g77f587896757 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1676 [inline]
sb_start_intwrite include/linux/fs.h:1859 [inline]
ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
ocfs2_write_begin_inline fs/ocfs2/aops.c:1480 [inline]
ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1583 [inline]
ocfs2_write_begin_nolock+0x226b/0x4d30 fs/ocfs2/aops.c:1669
ocfs2_write_begin+0x205/0x3a0 fs/ocfs2/aops.c:1903
generic_perform_write+0x399/0x840 mm/filemap.c:4019
ocfs2_file_write_iter+0x17b4/0x1f60 fs/ocfs2/file.c:2455
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xa72/0xc90 fs/read_write.c:590
ksys_write+0x1a0/0x2c0 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa601be8f19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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:00007ffc8af27958 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007fa601be8f19
RDX: 0000000000000020 RSI: 0000000020000840 RDI: 0000000000000004
RBP: 00007fa601c615f0 R08: 000055556916e4c0 R09: 000055556916e4c0
R10: 000055556916e4c0 R11: 0000000000000246 R12: 00007ffc8af27980
R13: 00007ffc8af27ba8 R14: 431bde82d7b634db R15: 00007fa601c3203b
</TASK>

---
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#syz test: git://repo/address.git branch-or-commit-hash
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Next message: Rob Herring (Arm): "Re: [PATCH v4] dt-bindings: watchdog: qcom-wdt: document support on SA8255p"
Previous message: Jeff Layton: "Re: [PATCH v2] timekeeping: move multigrain timestamp floor handling into timekeeper"
In reply to: syzbot: "[syzbot] [ocfs2?] possible deadlock in ocfs2_write_begin_nolock"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]