[syzbot] [ext4?] possible deadlock in ext4_setattr
From: syzbot
Date: Sat Jan 14 2023 - 02:51:44 EST
Hello,
syzbot found the following issue on:
HEAD commit: 358a161a6a9e Merge branch 'for-next/fixes' 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=166001ba480000
kernel config: https://syzkaller.appspot.com/x/.config?x=2573056c6a11f00d
dashboard link: https://syzkaller.appspot.com/bug?extid=cbb68193bdb95af4340a
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1287585a480000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=167d644a480000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/99d14e0f4c19/disk-358a161a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/23275b612976/vmlinux-358a161a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed79195fac61/Image-358a161a.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6e1f0d31d9b5/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cbb68193bdb95af4340a@xxxxxxxxxxxxxxxxxxxxxxxxx
EXT4-fs error (device loop0): ext4_mb_mark_diskspace_used:3789: comm syz-executor184: Allocating blocks 44-48 which overlap fs metadata
EXT4-fs error (device loop0): ext4_xattr_block_set:2175: inode #12: comm syz-executor184: bad block 0
======================================================
WARNING: possible circular locking dependency detected
6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0 Not tainted
------------------------------------------------------
syz-executor184/4449 is trying to acquire lock:
ffff0000cb1ae540 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:801 [inline]
ffff0000cb1ae540 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_setattr+0x804/0xb38 fs/ext4/inode.c:5545
but task is already holding lock:
ffff0000cb1ae3a0 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
ffff0000cb1ae3a0 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: do_truncate+0xf8/0x154 fs/open.c:63
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}:
down_write+0x5c/0x88 kernel/locking/rwsem.c:1562
inode_lock include/linux/fs.h:756 [inline]
ext4_xattr_inode_create fs/ext4/xattr.c:1457 [inline]
ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1540 [inline]
ext4_xattr_set_entry+0xdf4/0xe40 fs/ext4/xattr.c:1669
ext4_xattr_block_set+0x3d0/0x1404 fs/ext4/xattr.c:1975
ext4_xattr_set_handle+0x724/0x9a0 fs/ext4/xattr.c:2390
ext4_xattr_set+0x104/0x1d4 fs/ext4/xattr.c:2492
ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
__vfs_setxattr+0x290/0x29c fs/xattr.c:202
__vfs_setxattr_noperm+0xcc/0x320 fs/xattr.c:236
__vfs_setxattr_locked+0x16c/0x194 fs/xattr.c:297
vfs_setxattr+0xf4/0x1f4 fs/xattr.c:323
do_setxattr fs/xattr.c:608 [inline]
setxattr fs/xattr.c:631 [inline]
path_setxattr+0x32c/0x424 fs/xattr.c:650
__do_sys_setxattr fs/xattr.c:666 [inline]
__se_sys_setxattr fs/xattr.c:662 [inline]
__arm64_sys_setxattr+0x2c/0x40 fs/xattr.c:662
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
-> #2 (&ei->xattr_sem){++++}-{3:3}:
down_write+0x5c/0x88 kernel/locking/rwsem.c:1562
ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
ext4_xattr_set_handle+0xd0/0x9a0 fs/ext4/xattr.c:2305
ext4_initxattrs+0x50/0xac fs/ext4/xattr_security.c:44
security_inode_init_security+0x208/0x278 security/security.c:1147
ext4_init_security+0x44/0x58 fs/ext4/xattr_security.c:58
__ext4_new_inode+0x1a88/0x1c78 fs/ext4/ialloc.c:1324
ext4_create+0x124/0x26c fs/ext4/namei.c:2809
lookup_open fs/namei.c:3413 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x804/0x11f0 fs/namei.c:3711
do_filp_open+0xdc/0x1b8 fs/namei.c:3741
do_sys_openat2+0xb8/0x22c fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1337
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
-> #1 (jbd2_handle){.+.+}-{0:0}:
start_this_handle+0x6e0/0x7fc fs/jbd2/transaction.c:463
jbd2__journal_start+0x148/0x1f0 fs/jbd2/transaction.c:520
__ext4_journal_start_sb+0x158/0x210 fs/ext4/ext4_jbd2.c:111
__ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
ext4_truncate+0x3b4/0x72c fs/ext4/inode.c:4315
ext4_setattr+0x900/0xb38 fs/ext4/inode.c:5622
notify_change+0x738/0x7d0 fs/attr.c:482
do_truncate+0x10c/0x154 fs/open.c:65
do_sys_ftruncate+0x1b4/0x1c4 fs/open.c:193
__do_sys_ftruncate fs/open.c:204 [inline]
__se_sys_ftruncate fs/open.c:202 [inline]
__arm64_sys_ftruncate+0x28/0x38 fs/open.c:202
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
-> #0 (mapping.invalidate_lock){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668
down_write+0x5c/0x88 kernel/locking/rwsem.c:1562
filemap_invalidate_lock include/linux/fs.h:801 [inline]
ext4_setattr+0x804/0xb38 fs/ext4/inode.c:5545
notify_change+0x738/0x7d0 fs/attr.c:482
do_truncate+0x10c/0x154 fs/open.c:65
handle_truncate+0xf4/0x154 fs/namei.c:3216
do_open fs/namei.c:3561 [inline]
path_openat+0xee0/0x11f0 fs/namei.c:3714
do_filp_open+0xdc/0x1b8 fs/namei.c:3741
do_sys_openat2+0xb8/0x22c fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1337
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
other info that might help us debug this:
Chain exists of:
mapping.invalidate_lock --> &ei->xattr_sem --> &ea_inode->i_rwsem#8/1
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ea_inode->i_rwsem#8/1);
lock(&ei->xattr_sem);
lock(&ea_inode->i_rwsem#8/1);
lock(mapping.invalidate_lock);
*** DEADLOCK ***
2 locks held by syz-executor184/4449:
#0: ffff0000c6723460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x20/0x64 fs/namespace.c:508
#1: ffff0000cb1ae3a0 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
#1: ffff0000cb1ae3a0 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: do_truncate+0xf8/0x154 fs/open.c:63
stack backtrace:
CPU: 1 PID: 4449 Comm: syz-executor184 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call trace:
dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:163
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2055
check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668
down_write+0x5c/0x88 kernel/locking/rwsem.c:1562
filemap_invalidate_lock include/linux/fs.h:801 [inline]
ext4_setattr+0x804/0xb38 fs/ext4/inode.c:5545
notify_change+0x738/0x7d0 fs/attr.c:482
do_truncate+0x10c/0x154 fs/open.c:65
handle_truncate+0xf4/0x154 fs/namei.c:3216
do_open fs/namei.c:3561 [inline]
path_openat+0xee0/0x11f0 fs/namei.c:3714
do_filp_open+0xdc/0x1b8 fs/namei.c:3741
do_sys_openat2+0xb8/0x22c fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1337
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
---
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