WARNING in usb_ep_enable

Status: upstream: reported C repro on 2026/07/31 17:13
Subsystems: usb
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+7b70c4a6021fd49c4151@syzkaller.appspotmail.com
First crash: 15d, last: 1h47m
Cause bisection: introduced by (bisect log) :
commit 973a57891608a98e894db2887f278777f564de18
Author: Chris Wulff <crwulff@gmail.com>
Date: Thu Jul 25 01:04:20 2024 +0000

  usb: gadget: core: Check for unset descriptor

Crash: WARNING in usb_ep_enable (log)
Repro: C syz .config
  
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
ee053112 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ✅ VMHostTrigger: ❌ WARNING in usb_ep_enable 2026/07/31 02:54 2026/07/31 02:54 2026/07/31 04:00 aaffb173
Discussions (3)
Title Replies (including bot) Last reply
[PATCH v2] usb: gadget: f_hid: reject zero report length 1 (1) 2026/08/02 18:12
[PATCH] usb: gadget: f_hid: reject zero report length 2 (2) 2026/08/02 06:47
[syzbot] [usb?] WARNING in usb_ep_enable 0 (3) 2026/08/01 20:52
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in usb_ep_enable origin:upstream -1 syz, C 45 13h50m 13d 0/3 upstream: reported C repro on 2026/07/31 20:18
android-6-12 WARNING in usb_ep_enable -1 syz, C 22 2d14h 15d 0/1 premoderation: reported C repro on 2026/07/30 13:40
linux-6.1 WARNING in usb_ep_enable -1 syz, C 47 16h47m 13d 0/3 upstream: reported C repro on 2026/08/01 09:05
linux-6.6 WARNING in usb_ep_enable -1 syz, C 36 13h05m 13d 0/2 upstream: reported C repro on 2026/07/31 21:09
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/01 20:52 30m lurenjia534@outlook.com patch git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 5d5fd841c34649f1b09220fe58e59dffd61c447d OK log

Sample crash report:
------------[ cut here ]------------
usb_ep_enable: ep129 (ep1in-bulk) has maxpacket 0
WARNING: drivers/usb/gadget/udc/core.c:125 at usb_ep_enable+0x148/0x480 drivers/usb/gadget/udc/core.c:124, CPU#1: ktimers/1/29
Modules linked in:
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:usb_ep_enable+0x1bc/0x480 drivers/usb/gadget/udc/core.c:124
Code: 7a 35 04 fb 49 83 3f 00 48 c7 c0 a0 6b 1f 8c 49 c7 c0 c0 6b 1f 8c 4c 0f 44 c0 4c 89 f7 48 c7 c6 55 f3 af 8d 44 89 ea 4c 89 e1 <67> 48 0f b9 3a bd ea ff ff ff 0f 1f 44 00 00 e8 c0 be 9a fa 65 8b
RSP: 0018:ffffc90000a3f6b8 EFLAGS: 00010282
RAX: ffffffff8c1f6ba0 RBX: ffff888027b20120 RCX: ffffffff8c1f8a20
RDX: 0000000000000081 RSI: ffffffff8daff355 RDI: ffffffff8fbc5600
RBP: dffffc0000000000 R08: ffffffff8c1f6bc0 R09: 0000000000000100
R10: 0000000000000100 R11: 0000000000000003 R12: ffffffff8c1f8a20
R13: 0000000000000081 R14: ffffffff8fbc5600 R15: ffff888027b20138
FS:  0000000000000000(0000) GS:ffff888125d46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa380a8a6de CR3: 00000000468ea000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 hidg_set_alt+0x12a/0xa50 drivers/usb/gadget/function/f_hid.c:1042
 set_config+0x749/0x1160 drivers/usb/gadget/composite.c:1018
 composite_setup+0x1de7/0x3480 drivers/usb/gadget/composite.c:1901
 configfs_composite_setup+0xbd/0x100 drivers/usb/gadget/configfs.c:1877
 dummy_timer+0x2f77/0x4d50 drivers/usb/gadget/udc/dummy_hcd.c:1951
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2096
 hrtimer_run_softirq+0x18f/0x260 kernel/time/hrtimer.c:2113
 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1151
 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	7a 35                	jp     0x37
   2:	04 fb                	add    $0xfb,%al
   4:	49 83 3f 00          	cmpq   $0x0,(%r15)
   8:	48 c7 c0 a0 6b 1f 8c 	mov    $0xffffffff8c1f6ba0,%rax
   f:	49 c7 c0 c0 6b 1f 8c 	mov    $0xffffffff8c1f6bc0,%r8
  16:	4c 0f 44 c0          	cmove  %rax,%r8
  1a:	4c 89 f7             	mov    %r14,%rdi
  1d:	48 c7 c6 55 f3 af 8d 	mov    $0xffffffff8daff355,%rsi
  24:	44 89 ea             	mov    %r13d,%edx
  27:	4c 89 e1             	mov    %r12,%rcx
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	bd ea ff ff ff       	mov    $0xffffffea,%ebp
  34:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  39:	e8 c0 be 9a fa       	call   0xfa9abefe
  3e:	65                   	gs
  3f:	8b                   	.byte 0x8b

Crashes (431):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/13 15:33 upstream 3d6d817622b0 359b2492 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/13 10:24 upstream 3d6d817622b0 359b2492 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/12 11:32 upstream f5bbbfec59b4 f8d35649 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/11 10:27 upstream d58772d8520c 508909ea .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/10 15:24 upstream db2ddb871435 5d63f80b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/10 01:58 upstream b9b3e33b70b7 5d63f80b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/07/30 17:05 upstream 11028ab62899 2377cd3d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/07/30 15:18 upstream 11028ab62899 2377cd3d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/13 00:44 upstream 3d6d817622b0 359b2492 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/12 15:59 upstream f5bbbfec59b4 ee03bfea .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/10 10:56 upstream db2ddb871435 558388e4 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/09 23:16 upstream b643e495ae92 5d63f80b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/09 14:07 upstream 06cf61899d64 5d63f80b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/12 15:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 7ae4acc7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/08/14 12:06 upstream 2f1baf1fc892 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
2026/08/14 07:49 upstream 2f1baf1fc892 b13552fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/08/14 00:02 upstream 3aa1dcaa4f6f a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/13 17:36 upstream 3d6d817622b0 a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/08/13 08:57 upstream 3d6d817622b0 67796a05 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/13 02:13 upstream 3d6d817622b0 7ae4acc7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/08/13 00:34 upstream 3d6d817622b0 7ae4acc7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/08/12 08:35 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/08/12 06:45 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/08/12 04:59 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/08/12 00:55 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/11 21:57 upstream d58772d8520c 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/08/11 11:51 upstream d58772d8520c 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/11 06:12 upstream d58772d8520c 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/11 02:57 upstream d58772d8520c 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/08/10 23:52 upstream db2ddb871435 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/08/10 14:00 upstream db2ddb871435 558388e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/10 13:52 upstream db2ddb871435 558388e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/08/10 10:24 upstream db2ddb871435 558388e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/08/09 15:53 upstream 06cf61899d64 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/08/14 06:36 upstream 3aa1dcaa4f6f b13552fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/11 08:05 upstream d58772d8520c 508909ea .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in usb_ep_enable
2026/08/09 15:37 upstream 06cf61899d64 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/14 01:31 upstream 3aa1dcaa4f6f b13552fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/14 01:30 upstream 3aa1dcaa4f6f b13552fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/13 22:22 upstream 3aa1dcaa4f6f b13552fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/13 19:27 upstream 3aa1dcaa4f6f 4d118901 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/12 22:23 upstream 3d6d817622b0 359b2492 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/12 22:11 upstream 3d6d817622b0 359b2492 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/12 18:41 upstream 3d6d817622b0 ee03bfea .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/12 10:29 upstream f5bbbfec59b4 ee03bfea .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/11 23:05 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/11 17:15 upstream f5bbbfec59b4 557a89d3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/11 05:03 upstream d58772d8520c 508909ea .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 20:08 upstream db2ddb871435 558388e4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 18:56 upstream db2ddb871435 558388e4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 17:38 upstream db2ddb871435 558388e4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 12:07 upstream db2ddb871435 558388e4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 08:14 upstream db2ddb871435 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 07:38 upstream db2ddb871435 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 05:00 upstream b643e495ae92 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/10 01:18 upstream b643e495ae92 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/09 19:20 upstream b643e495ae92 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/08/13 21:20 linux-next 2697ef8943c9 a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/08/13 15:04 linux-next 28d012efb432 a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/08/12 15:16 linux-next 5e6de6a2b522 7ae4acc7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/08/11 18:30 linux-next 3d08ff75a47a 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/08/11 13:59 linux-next 3d08ff75a47a 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/08/06 21:35 linux-next cc2b5f627e8c c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in usb_ep_enable
2026/08/10 22:24 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ba5cc80fd326 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/08/10 06:24 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ba5cc80fd326 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/08/09 12:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ba5cc80fd326 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/08/13 05:52 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 3d6d817622b0 359b2492 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in usb_ep_enable
* Struck through repros no longer work on HEAD.