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: 49d, last: 23h05m
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 (4)
Title Replies (including bot) Last reply
[syzbot] Monthly usb report (Sep 2026) 0 (1) 2026/09/04 12:33
[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 54 6d15h 47d 0/3 upstream: reported C repro on 2026/07/31 20:18
android-6-12 WARNING in usb_ep_enable -1 syz, C 25 19d 48d 0/1 premoderation: reported C repro on 2026/07/30 13:40
linux-6.1 WARNING in usb_ep_enable -1 syz, C 78 5d02h 47d 0/3 upstream: reported C repro on 2026/08/01 09:05
linux-6.6 WARNING in usb_ep_enable -1 syz, C 46 5d03h 47d 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#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 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: 9a 2e 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 c5 fb 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 b7 9a fa 65 8b
RSP: 0018:ffffc900001576b8 EFLAGS: 00010286
RAX: ffffffff8c1f6ba0 RBX: ffff888027ccc120 RCX: ffffffff8c1f8a20
RDX: 0000000000000081 RSI: ffffffff8daffbc5 RDI: ffffffff8fbc58f0
RBP: dffffc0000000000 R08: ffffffff8c1f6bc0 R09: 0000000000000100
R10: 0000000000000100 R11: 0000000000000003 R12: ffffffff8c1f8a20
R13: 0000000000000081 R14: ffffffff8fbc58f0 R15: ffff888027ccc138
FS:  0000000000000000(0000) GS:ffff888125c45000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8a96dfd5e0 CR3: 0000000028d08000 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), 1 bytes skipped:
   0:	2e 04 fb             	cs add $0xfb,%al
   3:	49 83 3f 00          	cmpq   $0x0,(%r15)
   7:	48 c7 c0 a0 6b 1f 8c 	mov    $0xffffffff8c1f6ba0,%rax
   e:	49 c7 c0 c0 6b 1f 8c 	mov    $0xffffffff8c1f6bc0,%r8
  15:	4c 0f 44 c0          	cmove  %rax,%r8
  19:	4c 89 f7             	mov    %r14,%rdi
  1c:	48 c7 c6 c5 fb af 8d 	mov    $0xffffffff8daffbc5,%rsi
  23:	44 89 ea             	mov    %r13d,%edx
  26:	4c 89 e1             	mov    %r12,%rcx
* 29:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2e:	bd ea ff ff ff       	mov    $0xffffffea,%ebp
  33:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  38:	e8 c0 b7 9a fa       	call   0xfa9ab7fd
  3d:	65                   	gs
  3e:	8b                   	.byte 0x8b

Crashes (781):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/14 18:29 upstream 2f1baf1fc892 6f9b3e89 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in usb_ep_enable
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
2026/08/14 16:37 upstream 2f1baf1fc892 2cf1fbb7 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream 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
2026/09/05 10:58 linux-next 9d80aa4617b3 4f7b22a0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in usb_ep_enable
2026/08/31 11:01 linux-next e30626823a40 2f52988a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in usb_ep_enable
2026/08/31 04:25 linux-next e30626823a40 2f52988a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce 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
2026/09/12 09:39 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/12 00:28 upstream 3026c6e4f223 b6a5eeb7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/11 04:21 upstream 08df884136f1 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/09/10 16:59 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/08 14:28 upstream 28924df2a08f 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/09/08 05:17 upstream 28924df2a08f 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/08 02:25 upstream c297ed90fbba 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in usb_ep_enable
2026/09/07 15:21 upstream df2908090cda 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/07 02:55 upstream 2beb1b31a12b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/06 18:34 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/09/06 16:19 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/09/06 10:45 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in usb_ep_enable
2026/09/06 00:27 upstream 0d9ff90a5422 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in usb_ep_enable
2026/08/31 19:05 upstream cee9395acd80 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in usb_ep_enable
2026/09/10 15:13 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/09/10 10:55 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/09/10 03:28 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/09/06 00:06 upstream 4d7d9486c04d 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in usb_ep_enable
2026/08/28 04:27 upstream 818bebeb63dd e2fa417d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in usb_ep_enable
2026/09/16 10:41 upstream 50d05c7c76c9 12a0a44a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/16 01:17 upstream 50d05c7c76c9 12a0a44a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/15 17:34 upstream 50d05c7c76c9 f41e228a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/15 13:07 upstream 50d05c7c76c9 f41e228a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/15 00:51 upstream 50d05c7c76c9 81a27d1a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/14 13:58 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/14 12:48 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/14 06:31 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/13 18:43 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/13 14:35 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/12 22:56 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/12 02:15 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/10 23:21 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/10 22:12 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/10 20:22 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/10 18:44 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/10 12:12 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/10 00:32 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/09 12:35 upstream 893e11787f78 edec9137 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/09 09:55 upstream 5acbae5f7eb3 8387c273 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/08 23:43 upstream 5acbae5f7eb3 8387c273 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/08 18:46 upstream 5acbae5f7eb3 351387c4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/07 06:19 upstream df2908090cda 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/06 08:36 upstream 9f0346dcbea3 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/06 01:36 upstream 4d7d9486c04d 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/05 13:54 upstream 4d7d9486c04d 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in usb_ep_enable
2026/09/12 16:03 linux-next a9d7ced84989 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/09/09 21:29 linux-next a9d7ced84989 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in usb_ep_enable
2026/09/11 11:54 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 b6a5eeb7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/09/08 13:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/09/07 13:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in usb_ep_enable
2026/09/04 22:29 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 73ae59e97596 44dda43b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in usb_ep_enable
2026/08/20 11:41 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 8da45c93dfa9 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in usb_ep_enable
* Struck through repros no longer work on HEAD.