[v5.15] possible deadlock in ext4_ind_migrate

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6139f2a02fe0 Linux 5.15.148
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=149e6428180000
kernel config: https://syzkaller.appspot.com/x/.config?x=c3cfb017ec09dfb8
dashboard link: https://syzkaller.appspot.com/bug?extid=fd478d786efc5e8813e9
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/863dea226ad0/disk-6139f2a0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/db1a0715548e/vmlinux-6139f2a0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/edd9bd0f16ff/Image-6139f2a0.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fd478d...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.15.148-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/4013 is trying to acquire lock:
ffff0000d48b6bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ind_migrate+0x170/0x58c fs/ext4/migrate.c:625

but task is already holding lock:
ffff00012198abd0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
ffff00012198abd0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: vfs_fileattr_set+0x110/0xad4 fs/ioctl.c:685

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#9){++++}-{3:3}:
down_read+0xc0/0x398 kernel/locking/rwsem.c:1488
inode_lock_shared include/linux/fs.h:797 [inline]
ext4_bmap+0x58/0x36c fs/ext4/inode.c:3152
bmap+0xa8/0xe8 fs/inode.c:1756
jbd2_journal_bmap fs/jbd2/journal.c:980 [inline]
__jbd2_journal_erase fs/jbd2/journal.c:1790 [inline]
jbd2_journal_flush+0x63c/0xaa0 fs/jbd2/journal.c:2496
ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
__ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
ext4_ioctl+0x3454/0x61bc fs/ext4/ioctl.c:1276
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__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:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #1 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
__mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596
mutex_lock_io_nested+0xcc/0x12c kernel/locking/mutex.c:777
__jbd2_log_wait_for_space+0x1a4/0x5cc fs/jbd2/checkpoint.c:71
add_transaction_credits+0x814/0xb90 fs/jbd2/transaction.c:299
start_this_handle+0x578/0x12a4 fs/jbd2/transaction.c:423
jbd2__journal_start+0x29c/0x7b4 fs/jbd2/transaction.c:521
__ext4_journal_start_sb+0x358/0x70c fs/ext4/ext4_jbd2.c:105
__ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
ext4_ind_migrate+0x1d0/0x58c fs/ext4/migrate.c:627
ext4_ioctl_setflags fs/ext4/ioctl.c:457 [inline]
ext4_fileattr_set+0xbe0/0x12d0 fs/ext4/ioctl.c:765
vfs_fileattr_set+0x70c/0xad4 fs/ioctl.c:700
do_vfs_ioctl+0x1634/0x2a38
__do_sys_ioctl fs/ioctl.c:872 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:860
__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:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0
(
&sbi->s_writepages_rwsem
){++++}-{0:0}
:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
percpu_down_write+0xd8/0x3b0 kernel/locking/percpu-rwsem.c:217
ext4_ind_migrate+0x170/0x58c fs/ext4/migrate.c:625
ext4_ioctl_setflags fs/ext4/ioctl.c:457 [inline]
ext4_fileattr_set+0xbe0/0x12d0 fs/ext4/ioctl.c:765
vfs_fileattr_set+0x70c/0xad4 fs/ioctl.c:700
do_vfs_ioctl+0x1634/0x2a38
__do_sys_ioctl fs/ioctl.c:872 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:860
__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:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

other info that might help us debug this:

Chain exists of:

&sbi->s_writepages_rwsem
--> &journal->j_checkpoint_mutex
--> &sb->s_type->i_mutex_key
#9


Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(
&sb->s_type->i_mutex_key
#9
);
lock(
&journal->j_checkpoint_mutex
);
lock(
&sb->s_type->i_mutex_key#9
);
lock(&sbi->s_writepages_rwsem);

*** DEADLOCK ***

2 locks held by syz-executor.0/4013:
#0: ffff0000d48b4460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write_file+0x64/0x1e8 fs/namespace.c:421
#1: ffff00012198abd0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#1: ffff00012198abd0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: vfs_fileattr_set+0x110/0xad4 fs/ioctl.c:685

stack backtrace:
CPU: 0 PID: 4013 Comm: syz-executor.0 Not tainted 5.15.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
percpu_down_write+0xd8/0x3b0 kernel/locking/percpu-rwsem.c:217
ext4_ind_migrate+0x170/0x58c fs/ext4/migrate.c:625
ext4_ioctl_setflags fs/ext4/ioctl.c:457 [inline]
ext4_fileattr_set+0xbe0/0x12d0 fs/ext4/ioctl.c:765
vfs_fileattr_set+0x70c/0xad4 fs/ioctl.c:700
do_vfs_ioctl+0x1634/0x2a38
__do_sys_ioctl fs/ioctl.c:872 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:860
__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:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


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