syzbot


WARNING in kernfs_new_node

Status: upstream: reported on 2025/06/24 19:14
Reported-by: syzbot+9f7c7419ad603b146bad@syzkaller.appspotmail.com
First crash: 18d, last: 18d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in kernfs_new_node kernfs -1 C done done 2 1944d 2168d 15/29 fixed on 2020/05/10 10:41
upstream WARNING in kernfs_new_node (2) kernfs -1 1 434d 430d 0/29 auto-obsoleted due to no activity on 2024/08/12 04:32
upstream WARNING in kernfs_new_node (3) kernfs -1 syz error error 31 1d06h 327d 0/29 upstream: reported syz repro on 2024/08/19 18:26

Sample crash report:
usb 2-1: Direct firmware load for ueagle-atm/eagleII.fw failed with error -2
usb 2-1: Falling back to sysfs fallback for: ueagle-atm/eagleII.fw
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5835 at fs/kernfs/dir.c:526 kernfs_get fs/kernfs/dir.c:526 [inline]
WARNING: CPU: 0 PID: 5835 at fs/kernfs/dir.c:526 kernfs_new_node+0x1f9/0x260 fs/kernfs/dir.c:703
Modules linked in:
CPU: 0 PID: 5835 Comm: kworker/0:4 Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events request_firmware_work_func
RIP: 0010:kernfs_get fs/kernfs/dir.c:526 [inline]
RIP: 0010:kernfs_new_node+0x1f9/0x260 fs/kernfs/dir.c:703
Code: ff df 80 3c 08 00 74 08 4c 89 ff e8 41 f9 ca ff 49 89 1f 4c 89 f0 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 67 51 72 ff <0f> 0b eb 9e 89 e9 80 e1 07 fe c1 38 c1 0f 8c 45 fe ff ff 48 89 ef
RSP: 0018:ffffc90004a0f618 EFLAGS: 00010293
RAX: ffffffff82134469 RBX: ffff88802ea3a6c8 RCX: ffff88802c0e9e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88802ea3a6cb R09: 1ffff11005d474d9
R10: dffffc0000000000 R11: ffffed1005d474da R12: 00000000000041ed
R13: 0000000000000000 R14: ffff88802fe380f8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2c517ff8 CR3: 000000005a111000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kernfs_create_dir_ns+0x44/0x120 fs/kernfs/dir.c:1061
 sysfs_create_dir_ns+0x124/0x280 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x6b8/0xc70 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x156/0x220 lib/kobject.c:426
 class_dir_create_and_add drivers/base/core.c:3226 [inline]
 get_device_parent+0x316/0x390 drivers/base/core.c:3277
 device_add+0x2e1/0xc20 drivers/base/core.c:3607
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:82 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:158 [inline]
 firmware_fallback_sysfs+0x2e9/0x940 drivers/base/firmware_loader/fallback.c:234
 _request_firmware+0xed9/0x1510 drivers/base/firmware_loader/main.c:936
 request_firmware_work_func+0xb0/0x1b0 drivers/base/firmware_loader/main.c:1189
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 19:13 linux-6.6.y 6282921b6825 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in kernfs_new_node
* Struck through repros no longer work on HEAD.