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Date: Tue, 14 May 2024 08:44:43 -0700
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Subject: Re: [syzbot] [kernfs?] [usb?] WARNING in kernfs_get (5)
From: syzbot <syzbot+2f44671e54488d20f0e6@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, 
	linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com, tj@kernel.org
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syzbot has found a reproducer for the following issue on:

HEAD commit:    26dd54d03cd9 Add linux-next specific files for 20240514
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1392596c980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8af44e051929224
dashboard link: https://syzkaller.appspot.com/bug?extid=2f44671e54488d20f0e6
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=14b06900980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dca5ce975d7a/disk-26dd54d0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/24844585ee37/vmlinux-26dd54d0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7ea82f6342f5/bzImage-26dd54d0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2f44671e54488d20f0e6@syzkaller.appspotmail.com

usb 2-1: Direct firmware load for ueagle-atm/eagleI.fw failed with error -2
usb 2-1: Falling back to sysfs fallback for: ueagle-atm/eagleI.fw
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5166 at fs/kernfs/dir.c:526 kernfs_get+0x71/0x90 fs/kernfs/dir.c:526
Modules linked in:
CPU: 0 PID: 5166 Comm: kworker/0:4 Not tainted 6.9.0-next-20240514-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events request_firmware_work_func
RIP: 0010:kernfs_get+0x71/0x90 fs/kernfs/dir.c:526
Code: 23 e8 63 b0 5e ff 48 89 df be 04 00 00 00 e8 96 6c c4 ff f0 ff 03 eb 05 e8 4c b0 5e ff 5b 5d c3 cc cc cc cc e8 40 b0 5e ff 90 <0f> 0b 90 eb d7 89 d9 80 e1 07 80 c1 03 38 c1 7c b7 48 89 df e8 96
RSP: 0018:ffffc90003bdf6e0 EFLAGS: 00010293
RAX: ffffffff82379c40 RBX: ffff8880770dff00 RCX: ffff88802729da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff82379c14 R09: 1ffff1100ee1bfe0
R10: dffffc0000000000 R11: ffffed100ee1bfe1 R12: dffffc0000000000
R13: ffff88802a984008 R14: ffffffff8c4497f0 R15: ffff88802a984038
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55ba7ad988 CR3: 0000000024c16000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sysfs_get include/linux/sysfs.h:786 [inline]
 create_dir lib/kobject.c:89 [inline]
 kobject_add_internal+0x4ba/0x8d0 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x152/0x220 lib/kobject.c:426
 device_add+0x4e5/0xbf0 drivers/base/core.c:3659
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline]
 firmware_fallback_sysfs+0x307/0x9e0 drivers/base/firmware_loader/fallback.c:238
 _request_firmware+0xcf5/0x12b0 drivers/base/firmware_loader/main.c:914
 request_firmware_work_func+0x12a/0x280 drivers/base/firmware_loader/main.c:1165
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>


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If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.