linux-kernel - [syzbot] [ext4?] [ocfs2?] possible deadlock in dqget

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Message-ID: <66fbae37.050a0220.6bad9.0050.GAE@google.com>
Date: Tue, 01 Oct 2024 01:09:27 -0700
From: syzbot <syzbot+6e493c165d26d6fcbf72@...kaller.appspotmail.com>
To: jack@...e.com, jlbec@...lplan.org, joseph.qi@...ux.alibaba.com, 
	linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org, mark@...heh.com, 
	ocfs2-devel@...ts.linux.dev, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [ext4?] [ocfs2?] possible deadlock in dqget

Hello,

syzbot found the following issue on:

HEAD commit:    5f5673607153 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=104a559f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=dedbcb1ff4387972
dashboard link: https://syzkaller.appspot.com/bug?extid=6e493c165d26d6fcbf72
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16d3de27980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16f786a9980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/40172aed5414/disk-5f567360.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/58372f305e9d/vmlinux-5f567360.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d2aae6fa798f/Image-5f567360.gz.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/23ae94668485/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/942e4e36cd02/mount_2.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6e493c165d26d6fcbf72@...kaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc7-syzkaller-g5f5673607153 #0 Not tainted
------------------------------------------------------
syz-executor334/6555 is trying to acquire lock:
ffff0000e436e0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: wait_on_dquot fs/quota/dquot.c:356 [inline]
ffff0000e436e0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dqget+0x5f0/0xcec fs/quota/dquot.c:972

but task is already holding lock:
ffff0000dcbec690 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
ffff0000dcbec690 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1dc/0x12d0 fs/ext4/xattr.c:2373

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&ei->xattr_sem){++++}-{3:3}:
       down_write+0x50/0xc0 kernel/locking/rwsem.c:1579
       ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
       ext4_xattr_set_handle+0x1dc/0x12d0 fs/ext4/xattr.c:2373
       ext4_initxattrs+0xa4/0x11c fs/ext4/xattr_security.c:44
       security_inode_init_security+0x210/0x3fc security/security.c:1744
       ext4_init_security+0x44/0x58 fs/ext4/xattr_security.c:58
       __ext4_new_inode+0x2a80/0x376c fs/ext4/ialloc.c:1326
       ext4_create+0x234/0x480 fs/ext4/namei.c:2832
       lookup_open fs/namei.c:3578 [inline]
       open_last_lookups fs/namei.c:3647 [inline]
       path_openat+0xfb4/0x29f8 fs/namei.c:3883
       do_filp_open+0x1bc/0x3cc fs/namei.c:3913
       do_sys_openat2+0x124/0x1b8 fs/open.c:1416
       do_sys_open fs/open.c:1431 [inline]
       __do_sys_openat fs/open.c:1447 [inline]
       __se_sys_openat fs/open.c:1442 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1442
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #4 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0xf34/0x11c4 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x298/0x544 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x3c/0x4c fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x3d0/0x71c fs/ocfs2/journal.c:352
       ocfs2_modify_bh+0xe4/0x484 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0xec8/0x1550 fs/ocfs2/quota_local.c:769
       dquot_load_quota_sb+0x700/0xb48 fs/quota/dquot.c:2460
       dquot_load_quota_inode+0x280/0x4f4 fs/quota/dquot.c:2497
       ocfs2_enable_quotas+0x17c/0x3cc fs/ocfs2/super.c:926
       ocfs2_fill_super+0x3c80/0x4740 fs/ocfs2/super.c:1141
       mount_bdev+0x1d4/0x2a0 fs/super.c:1679
       ocfs2_mount+0x44/0x58 fs/ocfs2/super.c:1188
       legacy_get_tree+0xd4/0x16c fs/fs_context.c:662
       vfs_get_tree+0x90/0x28c fs/super.c:1800
       do_new_mount+0x278/0x900 fs/namespace.c:3472
       path_mount+0x590/0xe04 fs/namespace.c:3799
       do_mount fs/namespace.c:3812 [inline]
       __do_sys_mount fs/namespace.c:4020 [inline]
       __se_sys_mount fs/namespace.c:3997 [inline]
       __arm64_sys_mount+0x45c/0x5a8 fs/namespace.c:3997
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #3 (&journal->j_trans_barrier){.+.+}-{3:3}:
       down_read+0x58/0x2fc kernel/locking/rwsem.c:1526
       ocfs2_start_trans+0x3c4/0x71c fs/ocfs2/journal.c:350
       ocfs2_modify_bh+0xe4/0x484 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0xec8/0x1550 fs/ocfs2/quota_local.c:769
       dquot_load_quota_sb+0x700/0xb48 fs/quota/dquot.c:2460
       dquot_load_quota_inode+0x280/0x4f4 fs/quota/dquot.c:2497
       ocfs2_enable_quotas+0x17c/0x3cc fs/ocfs2/super.c:926
       ocfs2_fill_super+0x3c80/0x4740 fs/ocfs2/super.c:1141
       mount_bdev+0x1d4/0x2a0 fs/super.c:1679
       ocfs2_mount+0x44/0x58 fs/ocfs2/super.c:1188
       legacy_get_tree+0xd4/0x16c fs/fs_context.c:662
       vfs_get_tree+0x90/0x28c fs/super.c:1800
       do_new_mount+0x278/0x900 fs/namespace.c:3472
       path_mount+0x590/0xe04 fs/namespace.c:3799
       do_mount fs/namespace.c:3812 [inline]
       __do_sys_mount fs/namespace.c:4020 [inline]
       __se_sys_mount fs/namespace.c:3997 [inline]
       __arm64_sys_mount+0x45c/0x5a8 fs/namespace.c:3997
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #2 (sb_internal#2){.+.+}-{0:0}:
       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+0x244/0x71c fs/ocfs2/journal.c:348
       ocfs2_acquire_dquot+0x3c4/0xa8c fs/ocfs2/quota_global.c:852
       dqget+0x660/0xcec fs/quota/dquot.c:977
       __dquot_initialize+0x344/0xc04 fs/quota/dquot.c:1505
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1567
       ocfs2_get_init_inode+0x14c/0x1b8 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x878/0x243c fs/ocfs2/namei.c:308
       ocfs2_create+0x194/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3578 [inline]
       open_last_lookups fs/namei.c:3647 [inline]
       path_openat+0xfb4/0x29f8 fs/namei.c:3883
       do_filp_open+0x1bc/0x3cc fs/namei.c:3913
       do_sys_openat2+0x124/0x1b8 fs/open.c:1416
       do_sys_open fs/open.c:1431 [inline]
       __do_sys_openat fs/open.c:1447 [inline]
       __se_sys_openat fs/open.c:1442 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1442
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #1 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       down_write+0x50/0xc0 kernel/locking/rwsem.c:1579
       ocfs2_create_local_dquot+0x1a0/0x1778 fs/ocfs2/quota_local.c:1227
       ocfs2_acquire_dquot+0x6fc/0xa8c fs/ocfs2/quota_global.c:875
       dqget+0x660/0xcec fs/quota/dquot.c:977
       __dquot_initialize+0x344/0xc04 fs/quota/dquot.c:1505
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1567
       ocfs2_get_init_inode+0x14c/0x1b8 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x878/0x243c fs/ocfs2/namei.c:308
       ocfs2_create+0x194/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3578 [inline]
       open_last_lookups fs/namei.c:3647 [inline]
       path_openat+0xfb4/0x29f8 fs/namei.c:3883
       do_filp_open+0x1bc/0x3cc fs/namei.c:3913
       do_sys_openat2+0x124/0x1b8 fs/open.c:1416
       do_sys_open fs/open.c:1431 [inline]
       __do_sys_openat fs/open.c:1447 [inline]
       __se_sys_openat fs/open.c:1442 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1442
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x33d8/0x779c kernel/locking/lockdep.c:5142
       lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
       __mutex_lock kernel/locking/mutex.c:752 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
       wait_on_dquot fs/quota/dquot.c:356 [inline]
       dqget+0x5f0/0xcec fs/quota/dquot.c:972
       __dquot_initialize+0x344/0xc04 fs/quota/dquot.c:1505
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1567
       __ext4_new_inode+0x664/0x376c fs/ext4/ialloc.c:991
       ext4_xattr_inode_create fs/ext4/xattr.c:1486 [inline]
       ext4_xattr_inode_lookup_create+0x9a4/0x19e4 fs/ext4/xattr.c:1596
       ext4_xattr_block_set+0x224/0x2e08 fs/ext4/xattr.c:1916
       ext4_xattr_set_handle+0xc68/0x12d0 fs/ext4/xattr.c:2458
       ext4_xattr_set+0x1e0/0x354 fs/ext4/xattr.c:2560
       ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
       __vfs_setxattr+0x3d8/0x400 fs/xattr.c:200
       __vfs_setxattr_noperm+0x110/0x578 fs/xattr.c:234
       __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295
       vfs_setxattr+0x1a8/0x344 fs/xattr.c:321
       do_setxattr fs/xattr.c:629 [inline]
       path_setxattr+0x30c/0x428 fs/xattr.c:658
       __do_sys_setxattr fs/xattr.c:676 [inline]
       __se_sys_setxattr fs/xattr.c:672 [inline]
       __arm64_sys_setxattr+0xbc/0xd8 fs/xattr.c:672
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

other info that might help us debug this:

Chain exists of:
  &dquot->dq_lock --> jbd2_handle --> &ei->xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->xattr_sem);
                               lock(jbd2_handle);
                               lock(&ei->xattr_sem);
  lock(&dquot->dq_lock);

 *** DEADLOCK ***

3 locks held by syz-executor334/6555:
 #0: ffff0000d7c00420 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:515
 #1: ffff0000dcbec9c0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline]
 #1: ffff0000dcbec9c0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:320
 #2: ffff0000dcbec690 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000dcbec690 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1dc/0x12d0 fs/ext4/xattr.c:2373

stack backtrace:
CPU: 0 UID: 0 PID: 6555 Comm: syz-executor334 Not tainted 6.11.0-rc7-syzkaller-g5f5673607153 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:319
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:326
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:119
 dump_stack+0x1c/0x28 lib/dump_stack.c:128
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2059
 check_noncircular+0x310/0x404 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 kernel/locking/lockdep.c:3868 [inline]
 __lock_acquire+0x33d8/0x779c kernel/locking/lockdep.c:5142
 lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759
 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
 __mutex_lock kernel/locking/mutex.c:752 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
 wait_on_dquot fs/quota/dquot.c:356 [inline]
 dqget+0x5f0/0xcec fs/quota/dquot.c:972
 __dquot_initialize+0x344/0xc04 fs/quota/dquot.c:1505
 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1567
 __ext4_new_inode+0x664/0x376c fs/ext4/ialloc.c:991
 ext4_xattr_inode_create fs/ext4/xattr.c:1486 [inline]
 ext4_xattr_inode_lookup_create+0x9a4/0x19e4 fs/ext4/xattr.c:1596
 ext4_xattr_block_set+0x224/0x2e08 fs/ext4/xattr.c:1916
 ext4_xattr_set_handle+0xc68/0x12d0 fs/ext4/xattr.c:2458
 ext4_xattr_set+0x1e0/0x354 fs/ext4/xattr.c:2560
 ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
 __vfs_setxattr+0x3d8/0x400 fs/xattr.c:200
 __vfs_setxattr_noperm+0x110/0x578 fs/xattr.c:234
 __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295
 vfs_setxattr+0x1a8/0x344 fs/xattr.c:321
 do_setxattr fs/xattr.c:629 [inline]
 path_setxattr+0x30c/0x428 fs/xattr.c:658
 __do_sys_setxattr fs/xattr.c:676 [inline]
 __se_sys_setxattr fs/xattr.c:672 [inline]
 __arm64_sys_setxattr+0xbc/0xd8 fs/xattr.c:672
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598


---
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