Hello,
syzbot found the following issue on:
HEAD commit: 59b723cd2adb Linux 6.12-rc6
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=1035f630580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=11254d3590b16717
dashboard link:
https://syzkaller.appspot.com/bug?extid=aa419d82b68e6a7e96c5
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=101e46a7980000
C reproducer:
https://syzkaller.appspot.com/x/repro.c?x=149aad5f980000
Downloadable assets:
disk image (non-bootable):
https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-59b723cd.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/6b98f620edf1/vmlinux-59b723cd.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/b5d1377ba568/bzImage-59b723cd.xz
mounted in repro:
https://storage.googleapis.com/syzbot-assets/6387bac8a9c0/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+aa419d...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
udevd/5325 is trying to acquire lock:
ffff88804002c1e8 (kn->active#5){++++}-{0:0}, at: __kernfs_remove+0x400/0x870 fs/kernfs/dir.c:1486
but task is already holding lock:
ffff88801f9de4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x17e/0x700 block/bdev.c:1087
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&disk->open_mutex){+.+.}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
bdev_open+0xf0/0xc50 block/bdev.c:904
bdev_file_open_by_dev+0x1b0/0x220 block/bdev.c:1018
disk_scan_partitions+0x1be/0x2b0 block/genhd.c:367
device_add_disk+0xd02/0x1000 block/genhd.c:510
pmem_attach_disk+0xdf7/0x10e0 drivers/nvdimm/pmem.c:576
nvdimm_bus_probe+0x147/0x4e0 drivers/nvdimm/bus.c:94
really_probe+0x2b8/0xad0 drivers/base/dd.c:658
__driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
driver_probe_device+0x50/0x430 drivers/base/dd.c:830
__driver_attach+0x45f/0x710 drivers/base/dd.c:1216
bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:370
bus_add_driver+0x346/0x670 drivers/base/bus.c:675
driver_register+0x23a/0x320 drivers/base/driver.c:246
do_one_initcall+0x248/0x880 init/main.c:1269
do_initcall_level+0x157/0x210 init/main.c:1331
do_initcalls+0x3f/0x80 init/main.c:1347
kernel_init_freeable+0x435/0x5d0 init/main.c:1580
kernel_init+0x1d/0x2b0 init/main.c:1469
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #1 (&nvdimm_namespace_key){+.+.}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
device_lock include/linux/device.h:1014 [inline]
uevent_show+0x17d/0x340 drivers/base/core.c:2736
dev_attr_show+0x55/0xc0 drivers/base/core.c:2430
sysfs_kf_seq_show+0x331/0x4c0 fs/sysfs/file.c:59
seq_read_iter+0x43f/0xd70 fs/seq_file.c:230
new_sync_read fs/read_write.c:488 [inline]
vfs_read+0x991/0xb70 fs/read_write.c:569
ksys_read+0x183/0x2b0 fs/read_write.c:712
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 (kn->active#5){++++}-{0:0}:
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
kernfs_drain+0x31c/0x6d0 fs/kernfs/dir.c:500
__kernfs_remove+0x400/0x870 fs/kernfs/dir.c:1486
kernfs_remove_by_name_ns+0xdc/0x160 fs/kernfs/dir.c:1694
sysfs_remove_file include/linux/sysfs.h:773 [inline]
device_remove_file drivers/base/core.c:3054 [inline]
device_del+0x56a/0x9b0 drivers/base/core.c:3859
drop_partition+0x11b/0x180 block/partitions/core.c:273
bdev_disk_changed+0x2bf/0x13f0 block/partitions/core.c:666
__loop_clr_fd drivers/block/loop.c:1182 [inline]
lo_release+0x53e/0x850 drivers/block/loop.c:1739
bdev_release+0x5dd/0x700
blkdev_release+0x15/0x20 block/fops.c:639
__fput+0x23f/0x880 fs/file_table.c:431
__do_sys_close fs/open.c:1567 [inline]
__se_sys_close fs/open.c:1552 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1552
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:
Chain exists of:
kn->active#5 --> &nvdimm_namespace_key --> &disk->open_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&disk->open_mutex);
lock(&nvdimm_namespace_key);
lock(&disk->open_mutex);
lock(kn->active#5);
*** DEADLOCK ***
1 lock held by udevd/5325:
#0: ffff88801f9de4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x17e/0x700 block/bdev.c:1087
stack backtrace:
CPU: 0 UID: 0 PID: 5325 Comm: udevd Not tainted 6.12.0-rc6-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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
kernfs_drain+0x31c/0x6d0 fs/kernfs/dir.c:500
__kernfs_remove+0x400/0x870 fs/kernfs/dir.c:1486
kernfs_remove_by_name_ns+0xdc/0x160 fs/kernfs/dir.c:1694
sysfs_remove_file include/linux/sysfs.h:773 [inline]
device_remove_file drivers/base/core.c:3054 [inline]
device_del+0x56a/0x9b0 drivers/base/core.c:3859
drop_partition+0x11b/0x180 block/partitions/core.c:273
bdev_disk_changed+0x2bf/0x13f0 block/partitions/core.c:666
__loop_clr_fd drivers/block/loop.c:1182 [inline]
lo_release+0x53e/0x850 drivers/block/loop.c:1739
bdev_release+0x5dd/0x700
blkdev_release+0x15/0x20 block/fops.c:639
__fput+0x23f/0x880 fs/file_table.c:431
__do_sys_close fs/open.c:1567 [inline]
__se_sys_close fs/open.c:1552 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1552
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: 0033:0x7f31211170a8
Code: 48 8b 05 83 9d 0d 00 64 c7 00 16 00 00 00 83 c8 ff 48 83 c4 20 5b c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 5b 48 8b 15 51 9d 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fffbff72f28 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f31215610e0 RCX: 00007f31211170a8
RDX: 000055bb50865e1f RSI: 00007fffbff72728 RDI: 0000000000000008
RBP: 000055be0b666270 R08: 0000000000000006 R09: e96079c9d5837796
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000002
R13: 000055be0b65a9a0 R14: 0000000000000008 R15: 000055be0b648910
</TASK>
loop0: p1 p2 p3
block device autoloading is deprecated and will be removed.
udevd[5325]: inotify_add_watch(7, /dev/loop0p1, 10) failed: No such file or directory
udevd[5325]: inotify_add_watch(7, /dev/loop0p1, 10) failed: No such file or directory
udevd[5325]: inotify_add_watch(7, /dev/loop0p1, 10) failed: No such file or directory
loop0: p1 p2 p3
loop0: p1 p2 p3
loop0: p1 p2 p3
loop0: p1 p2 p3
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loop0: p1 p2 p3
udevd[5325]: inotify_add_watch(7, /dev/loop0p1, 10) failed: No such file or directory
udevd[5325]: inotify_add_watch(7, /dev/loop0p1, 10) failed: No such file or directory
udevd[5325]: inotify_add_watch(7, /dev/loop0p1, 10) failed: No such file or directory
loop0: p1 p2 p3
loop0: p1 p2 p3
loop0: p1 p2 p3
loop0: p1 p2 p3
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loop0: p1 p2 p3
loop0: p1 p2 p3
---
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