[syzbot] [ext4?] possible deadlock in ext4_setattr (2)

From: syzbot
Date: Wed Jun 05 2024 - 17:04:43 EST

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Hello,

syzbot found the following issue on:

HEAD commit: cc8ed4d0a848 Merge tag 'drm-fixes-2024-06-01' of https://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13986f2c980000
kernel config: https://syzkaller.appspot.com/x/.config?x=733cc7a95171d8e7
dashboard link: https://syzkaller.appspot.com/bug?extid=95c8e4be52020572ac05
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-cc8ed4d0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/36abdd995432/vmlinux-cc8ed4d0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e4e0a6f67db/bzImage-cc8ed4d0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+95c8e4be52020572ac05@xxxxxxxxxxxxxxxxxxxxxxxxx

overlay: ./bus is not a directory
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc1-syzkaller-00267-gcc8ed4d0a848 #0 Not tainted
------------------------------------------------------
syz-executor.3/8218 is trying to acquire lock:
ffff888028d580c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_setattr+0x7fb/0x2700 fs/ext4/inode.c:5318

but task is already holding lock:
ffff88801db3c950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x10db/0x15e0 fs/jbd2/transaction.c:463

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (jbd2_handle){++++}-{0:0}:
start_this_handle+0x1101/0x15e0 fs/jbd2/transaction.c:463
jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:520
__ext4_journal_start_sb+0x358/0x660 fs/ext4/ext4_jbd2.c:112
ext4_sample_last_mounted fs/ext4/file.c:837 [inline]
ext4_file_open+0x636/0xc90 fs/ext4/file.c:865
do_dentry_open+0x910/0x1930 fs/open.c:955
do_open fs/namei.c:3650 [inline]
path_openat+0x1e3a/0x29f0 fs/namei.c:3807
do_filp_open+0x1dc/0x430 fs/namei.c:3834
do_sys_openat2+0x17a/0x1e0 fs/open.c:1405
do_sys_open fs/open.c:1420 [inline]
__do_sys_openat fs/open.c:1436 [inline]
__se_sys_openat fs/open.c:1431 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1431
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 (sb_internal){.+.+}-{0:0}:
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1655 [inline]
sb_start_intwrite include/linux/fs.h:1838 [inline]
ext4_evict_inode+0xd7b/0x17d0 fs/ext4/inode.c:212
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
dput+0x1f/0x30 fs/dcache.c:835
ovl_stack_put+0x60/0x90 fs/overlayfs/util.c:132
ovl_destroy_inode+0xc6/0x190 fs/overlayfs/super.c:182
destroy_inode+0xc4/0x1b0 fs/inode.c:311
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
shrink_kill fs/dcache.c:1048 [inline]
shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075
prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156
super_cache_scan+0x32a/0x550 fs/super.c:221
do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
shrink_slab_memcg mm/shrinker.c:548 [inline]
shrink_slab+0xa87/0x1310 mm/shrinker.c:626
shrink_one+0x493/0x7c0 mm/vmscan.c:4790
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #1 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:3783 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3797
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3890 [inline]
slab_alloc_node mm/slub.c:3980 [inline]
__do_kmalloc_node mm/slub.c:4120 [inline]
__kmalloc_node_noprof+0xbb/0x450 mm/slub.c:4128
kmalloc_node_noprof include/linux/slab.h:681 [inline]
kvmalloc_node_noprof+0x6f/0x1a0 mm/util.c:634
ext4_xattr_inode_cache_find fs/ext4/xattr.c:1535 [inline]
ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1581 [inline]
ext4_xattr_inode_lookup_create+0x4e8/0x1910 fs/ext4/xattr.c:1568
ext4_xattr_block_set+0x77a/0x3090 fs/ext4/xattr.c:1910
ext4_xattr_move_to_block fs/ext4/xattr.c:2663 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2738 [inline]
ext4_expand_extra_isize_ea+0xf57/0x1990 fs/ext4/xattr.c:2830
__ext4_expand_extra_isize+0x322/0x450 fs/ext4/inode.c:5782
ext4_try_to_expand_extra_isize fs/ext4/inode.c:5825 [inline]
__ext4_mark_inode_dirty+0x55a/0x890 fs/ext4/inode.c:5903
ext4_set_acl+0x453/0x5a0 fs/ext4/acl.c:263
set_posix_acl+0x25c/0x320 fs/posix_acl.c:955
vfs_set_acl+0x53d/0x940 fs/posix_acl.c:1134
do_set_acl+0xd9/0x1b0 fs/posix_acl.c:1279
do_setxattr+0xeb/0x170 fs/xattr.c:626
setxattr+0x15d/0x180 fs/xattr.c:652
path_setxattr+0x179/0x1e0 fs/xattr.c:671
__do_sys_lsetxattr fs/xattr.c:694 [inline]
__se_sys_lsetxattr fs/xattr.c:690 [inline]
__ia32_sys_lsetxattr+0xbd/0x160 fs/xattr.c:690
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #0 (&ei->xattr_sem){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
down_read+0x9a/0x330 kernel/locking/rwsem.c:1526
ext4_setattr+0x7fb/0x2700 fs/ext4/inode.c:5318
notify_change+0x742/0x11f0 fs/attr.c:497
chown_common+0x598/0x660 fs/open.c:790
do_fchownat+0x1af/0x210 fs/open.c:821
ksys_lchown include/linux/syscalls.h:1244 [inline]
__do_sys_lchown16 kernel/uid16.c:30 [inline]
__se_sys_lchown16 kernel/uid16.c:28 [inline]
__ia32_sys_lchown16+0xe6/0x120 kernel/uid16.c:28
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
&ei->xattr_sem --> sb_internal --> jbd2_handle

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
rlock(jbd2_handle);
lock(sb_internal);
lock(jbd2_handle);
rlock(&ei->xattr_sem);

*** DEADLOCK ***

3 locks held by syz-executor.3/8218:
#0: ffff88801db38420 (sb_writers#4){.+.+}-{0:0}, at: do_fchownat+0x11b/0x210 fs/open.c:818
#1: ffff888028d58400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
#1: ffff888028d58400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: chown_common+0x331/0x660 fs/open.c:780
#2: ffff88801db3c950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x10db/0x15e0 fs/jbd2/transaction.c:463

stack backtrace:
CPU: 1 PID: 8218 Comm: syz-executor.3 Not tainted 6.10.0-rc1-syzkaller-00267-gcc8ed4d0a848 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
down_read+0x9a/0x330 kernel/locking/rwsem.c:1526
ext4_setattr+0x7fb/0x2700 fs/ext4/inode.c:5318
notify_change+0x742/0x11f0 fs/attr.c:497
chown_common+0x598/0x660 fs/open.c:790
do_fchownat+0x1af/0x210 fs/open.c:821
ksys_lchown include/linux/syscalls.h:1244 [inline]
__do_sys_lchown16 kernel/uid16.c:30 [inline]
__se_sys_lchown16 kernel/uid16.c:28 [inline]
__ia32_sys_lchown16+0xe6/0x120 kernel/uid16.c:28
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf729f579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5e915ac EFLAGS: 00000292 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000000ee00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi

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Next message: Mark Brown: "Re: [PATCH] ASoC: rockchip: i2s-tdm: Fix trcm mode by setting clock on right mclk"
Previous message: Alex Bee: "Re: [PATCH 1/5] clk: rockchip: rk3128: Drop CLK_NR_CLKS usage"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]