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Message-ID: <66f7b39f.050a0220.46d20.0037.GAE@google.com>
Date: Sat, 28 Sep 2024 00:43:27 -0700
From: syzbot <syzbot+d91a6e2efb07bd3354e9@...kaller.appspotmail.com>
To: adilger.kernel@...ger.ca, jun.nie@...aro.org, linux-ext4@...r.kernel.org,
linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com, tytso@....edu
Subject: [syzbot] [ext4?] possible deadlock in ext4_xattr_inode_lookup_create
Hello,
syzbot found the following issue on:
HEAD commit: 2b7275670032 Add linux-next specific files for 20240925
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12fdd627980000
kernel config: https://syzkaller.appspot.com/x/.config?x=441f6022e7a2db73
dashboard link: https://syzkaller.appspot.com/bug?extid=d91a6e2efb07bd3354e9
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=1771ca80580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102e0907980000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/de8e955e430e/disk-2b727567.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cdc30f0c4010/vmlinux-2b727567.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5bce68c83e37/bzImage-2b727567.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b35179829fb5/mount_0.gz
The issue was bisected to:
commit 1e9d62d252812575ded7c620d8fc67c32ff06c16
Author: Jun Nie <jun.nie@...aro.org>
Date: Tue Jan 3 01:45:16 2023 +0000
ext4: optimize ea_inode block expansion
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14edcaa9980000
final oops: https://syzkaller.appspot.com/x/report.txt?x=16edcaa9980000
console output: https://syzkaller.appspot.com/x/log.txt?x=12edcaa9980000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d91a6e2efb07bd3354e9@...kaller.appspotmail.com
Fixes: 1e9d62d25281 ("ext4: optimize ea_inode block expansion")
EXT4-fs: Ignoring removed nomblk_io_submit option
======================================================
WARNING: possible circular locking dependency detected
6.11.0-next-20240925-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor177/5387 is trying to acquire lock:
ffff888071dd97c8 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
ffff888071dd97c8 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline]
ffff888071dd97c8 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: ext4_xattr_inode_lookup_create+0x1a31/0x1f20 fs/ext4/xattr.c:1596
but task is already holding lock:
ffff888071ddc7e0 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_truncate+0x994/0x11c0 fs/ext4/inode.c:4180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&ei->i_data_sem/3){++++}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
down_write+0x99/0x220 kernel/locking/rwsem.c:1577
ext4_update_i_disksize fs/ext4/ext4.h:3398 [inline]
ext4_xattr_inode_write fs/ext4/xattr.c:1452 [inline]
ext4_xattr_inode_lookup_create+0x16b8/0x1f20 fs/ext4/xattr.c:1602
ext4_xattr_ibody_set+0x214/0x730 fs/ext4/xattr.c:2269
ext4_xattr_set_handle+0xba6/0x1580 fs/ext4/xattr.c:2446
ext4_xattr_set+0x241/0x3d0 fs/ext4/xattr.c:2560
__vfs_setxattr+0x468/0x4a0 fs/xattr.c:200
__vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
vfs_setxattr+0x221/0x430 fs/xattr.c:321
do_setxattr fs/xattr.c:629 [inline]
path_setxattr+0x37e/0x4d0 fs/xattr.c:658
__do_sys_setxattr fs/xattr.c:676 [inline]
__se_sys_setxattr fs/xattr.c:672 [inline]
__x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:672
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 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
__lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
down_write+0x99/0x220 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:815 [inline]
ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline]
ext4_xattr_inode_lookup_create+0x1a31/0x1f20 fs/ext4/xattr.c:1596
ext4_xattr_block_set+0x274/0x3980 fs/ext4/xattr.c:1916
ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline]
ext4_expand_extra_isize_ea+0x12d7/0x1cf0 fs/ext4/xattr.c:2836
__ext4_expand_extra_isize+0x2fb/0x3e0 fs/ext4/inode.c:5831
ext4_try_to_expand_extra_isize fs/ext4/inode.c:5874 [inline]
__ext4_mark_inode_dirty+0x524/0x880 fs/ext4/inode.c:5952
ext4_ext_truncate+0x9f/0x2b0 fs/ext4/extents.c:4457
ext4_truncate+0xa1b/0x11c0 fs/ext4/inode.c:4185
ext4_evict_inode+0x90f/0xf50 fs/ext4/inode.c:263
evict+0x4e8/0x9b0 fs/inode.c:806
__dentry_kill+0x20d/0x630 fs/dcache.c:615
dput+0x19f/0x2b0 fs/dcache.c:857
do_renameat2+0xda1/0x13f0 fs/namei.c:5181
__do_sys_renameat2 fs/namei.c:5213 [inline]
__se_sys_renameat2 fs/namei.c:5210 [inline]
__x64_sys_renameat2+0xce/0xe0 fs/namei.c:5210
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:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ei->i_data_sem/3);
lock(&ea_inode->i_rwsem#8/1);
lock(&ei->i_data_sem/3);
lock(&ea_inode->i_rwsem#8/1);
*** DEADLOCK ***
7 locks held by syz-executor177/5387:
#0: ffff88802da0e420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
#1: ffff88802da0e730 (&type->s_vfs_rename_key){+.+.}-{3:3}, at: lock_rename fs/namei.c:3165 [inline]
#1: ffff88802da0e730 (&type->s_vfs_rename_key){+.+.}-{3:3}, at: do_renameat2+0x5cf/0x13f0 fs/namei.c:5114
#2: ffff88807755f0f0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
#2: ffff88807755f0f0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_two_directories+0x145/0x220 fs/namei.c:3131
#3: ffff888071dd83f8 (&type->i_mutex_dir_key#3/5){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
#3: ffff888071dd83f8 (&type->i_mutex_dir_key#3/5){+.+.}-{3:3}, at: lock_two_directories+0x16f/0x220 fs/namei.c:3132
#4: ffff88802da0e610 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1721 [inline]
#4: ffff88802da0e610 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1904 [inline]
#4: ffff88802da0e610 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2f4/0xf50 fs/ext4/inode.c:217
#5: ffff888071ddc7e0 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_truncate+0x994/0x11c0 fs/ext4/inode.c:4180
#6: ffff888071ddc620 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:161 [inline]
#6: ffff888071ddc620 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5871 [inline]
#6: ffff888071ddc620 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x491/0x880 fs/ext4/inode.c:5952
stack backtrace:
CPU: 0 UID: 0 PID: 5387 Comm: syz-executor177 Not tainted 6.11.0-next-20240925-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
__lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
down_write+0x99/0x220 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:815 [inline]
ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline]
ext4_xattr_inode_lookup_create+0x1a31/0x1f20 fs/ext4/xattr.c:1596
ext4_xattr_block_set+0x274/0x3980 fs/ext4/xattr.c:1916
ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline]
ext4_expand_extra_isize_ea+0x12d7/0x1cf0 fs/ext4/xattr.c:2836
__ext4_expand_extra_isize+0x2fb/0x3e0 fs/ext4/inode.c:5831
ext4_try_to_expand_extra_isize fs/ext4/inode.c:5874 [inline]
__ext4_mark_inode_dirty+0x524/0x880 fs/ext4/inode.c:5952
ext4_ext_truncate+0x9f/0x2b0 fs/ext4/extents.c:4457
ext4_truncate+0xa1b/0x11c0 fs/ext4/inode.c:4185
ext4_evict_inode+0x90f/0xf50 fs/ext4/inode.c:263
evict+0x4e8/0x9b0 fs/inode.c:806
__dentry_kill+0x20d/0x630 fs/dcache.c:615
dput+0x19f/0x2b0 fs/dcache.c:857
do_renameat2+0xda1/0x13f0 fs/namei.c:5181
__do_sys_renameat2 fs/namei.c:5213 [inline]
__se_sys_renameat2 fs/namei.c:5210 [inline]
__x64_sys_renameat2+0xce/0xe0 fs/namei.c:5210
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: 0033:0x7f9326d33469
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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:00007ffdce15cbc8 EFLAGS: 00000246 ORIG_RAX: 000000000000013c
RAX: ffffffffffffffda RBX: 00007f9326d7c0a0 RCX: 00007f9326d33469
RDX: 0000000000000005 RSI: 0000000020000080 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffdce15cc00
R10: 00000000200000c0 R11: 0000000000000246 R12: 00007ffdce15cbec
R13: 0000000000000031 R14: 431bde82d7b634db R15: 00007ffdce15cc20
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
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