From: syzbot <syzbot+19bed92c97bee999e5db@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, stern@rowland.harvard.edu,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [usb?] general protection fault in usb_gadget_udc_reset (4)
Date: Mon, 09 Mar 2026 08:43:01 -0700 [thread overview]
Message-ID: <69aeea85.050a0220.310d8.002a.GAE@google.com> (raw)
In-Reply-To: <04861347-b659-4bcc-91d4-4319432c8ba6@rowland.harvard.edu>
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in usb_gadget_udc_reset
usb 2-1: reset high-speed USB device number 8 using dummy_hcd
usb 2-1: device descriptor read/8, error -32
gadget gadget.1: Reset #1, gadget ffff888029d60c40 driver 0000000000000000
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 1 UID: 0 PID: 6630 Comm: kworker/1:8 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_gadget_udc_reset+0x45/0x80 drivers/usb/gadget/udc/core.c:1201
Code: 4c 89 f7 48 c7 c6 a0 d2 fb 8b 48 89 da 4c 89 f9 e8 20 5b fd ff 49 83 c7 40 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 ed da fb 00 4d 8b 1f 48 89 df 2e 2e
RSP: 0018:ffffc900049464c0 EFLAGS: 00010202
RAX: 0000000000000008 RBX: ffff888029d60c40 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888025502d6c R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1017124923 R12: ffff888029d60c40
R13: 1ffff110053d16a1 R14: ffff888029d60d58 R15: 0000000000000040
FS: 0000000000000000(0000) GS:ffff88812643d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c90080a138 CR3: 00000000114f4000 CR4: 00000000003526f0
Call Trace:
<TASK>
set_link_state+0x80b/0x1220 drivers/usb/gadget/udc/dummy_hcd.c:469
dummy_hub_control+0xa09/0x1a00 drivers/usb/gadget/udc/dummy_hcd.c:-1
rh_call_control drivers/usb/core/hcd.c:652 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:817 [inline]
usb_hcd_submit_urb+0xdbe/0x1b50 drivers/usb/core/hcd.c:1538
usb_start_wait_urb+0x12b/0x510 drivers/usb/core/message.c:59
usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
usb_control_msg+0x232/0x3e0 drivers/usb/core/message.c:154
set_port_feature drivers/usb/core/hub.c:466 [inline]
hub_port_reset+0x3c7/0x1820 drivers/usb/core/hub.c:3083
hub_port_init+0x299/0x28c0 drivers/usb/core/hub.c:4939
usb_reset_and_verify_device+0x1661/0x1af0 drivers/usb/core/hub.c:6215
usb_reset_device+0x551/0xb40 drivers/usb/core/hub.c:6410
sd_config+0x27f/0x15b0 drivers/media/usb/gspca/se401.c:221
gspca_dev_probe2+0x81e/0x1450 drivers/media/usb/gspca/gspca.c:1529
usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
__device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c8/0x450 drivers/base/dd.c:1033
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
bus_probe_device+0x12d/0x220 drivers/base/bus.c:574
device_add+0x7b6/0xb80 drivers/base/core.c:3689
usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2208
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
__device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c8/0x450 drivers/base/dd.c:1033
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
bus_probe_device+0x12d/0x220 drivers/base/bus.c:574
device_add+0x7b6/0xb80 drivers/base/core.c:3689
usb_new_device+0x9f8/0x16e0 drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2a49/0x4f60 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:usb_gadget_udc_reset+0x45/0x80 drivers/usb/gadget/udc/core.c:1201
Code: 4c 89 f7 48 c7 c6 a0 d2 fb 8b 48 89 da 4c 89 f9 e8 20 5b fd ff 49 83 c7 40 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 ed da fb 00 4d 8b 1f 48 89 df 2e 2e
RSP: 0018:ffffc900049464c0 EFLAGS: 00010202
RAX: 0000000000000008 RBX: ffff888029d60c40 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888025502d6c R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1017124923 R12: ffff888029d60c40
R13: 1ffff110053d16a1 R14: ffff888029d60d58 R15: 0000000000000040
FS: 0000000000000000(0000) GS:ffff88812643d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c90080a138 CR3: 00000000114f4000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 4c 89 f7 mov %r14,%rdi
3: 48 c7 c6 a0 d2 fb 8b mov $0xffffffff8bfbd2a0,%rsi
a: 48 89 da mov %rbx,%rdx
d: 4c 89 f9 mov %r15,%rcx
10: e8 20 5b fd ff call 0xfffd5b35
15: 49 83 c7 40 add $0x40,%r15
19: 4c 89 f8 mov %r15,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ff mov %r15,%rdi
33: e8 ed da fb 00 call 0xfbdb25
38: 4d 8b 1f mov (%r15),%r11
3b: 48 89 df mov %rbx,%rdi
3e: 2e cs
3f: 2e cs
Tested on:
commit: 65169048 Merge tag 'spi-fix-v7.0-rc2' of git://git.ker..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=10828d52580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2a019678b1a3a692
dashboard link: https://syzkaller.appspot.com/bug?extid=19bed92c97bee999e5db
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=1019a3aa580000
next prev parent reply other threads:[~2026-03-09 15:43 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-25 7:30 [syzbot] [usb?] general protection fault in usb_gadget_udc_reset (4) syzbot
2026-03-07 10:52 ` syzbot
2026-03-08 15:36 ` Alan Stern
2026-03-08 16:01 ` syzbot
2026-03-09 14:25 ` Alan Stern
2026-03-09 14:55 ` syzbot
2026-03-09 15:24 ` Alan Stern
2026-03-09 15:43 ` syzbot [this message]
2026-03-10 15:50 ` Alan Stern
2026-03-10 16:09 ` syzbot
2026-03-10 19:02 ` Alan Stern
2026-03-10 19:32 ` syzbot
2026-03-11 1:50 ` Alan Stern
2026-03-11 3:16 ` syzbot
2026-03-11 18:44 ` Alan Stern
2026-03-11 19:25 ` syzbot
2026-03-12 17:56 ` Alan Stern
2026-03-12 18:29 ` syzbot
2026-03-13 2:05 ` Alan Stern
2026-03-13 2:42 ` syzbot
2026-03-13 16:07 ` Alan Stern
2026-03-13 16:32 ` syzbot
2026-03-13 19:47 ` Alan Stern
2026-03-13 21:28 ` syzbot
2026-03-14 16:42 ` Alan Stern
2026-03-14 17:07 ` syzbot
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