WARNING in usb_ep_enable

Status: upstream: reported C repro on 2026/07/31 20:18
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+5bd412baa2c4211bdc7a@syzkaller.appspotmail.com
First crash: 10d, last: 1h57m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2026/08/01 upstream (ToT) 02dc699f83d0 C [report] WARNING in usb_ep_enable
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 WARNING in usb_ep_enable -1 syz, C 21 8h46m 11d 0/1 premoderation: reported C repro on 2026/07/30 13:40
linux-6.1 WARNING in usb_ep_enable -1 syz, C 41 2h57m 9d17h 0/3 upstream: reported C repro on 2026/08/01 09:05
upstream WARNING in usb_ep_enable usb prio:high -1 syz, C done 337 3h00m 10d 0/29 upstream: reported C repro on 2026/07/31 17:13
linux-6.6 WARNING in usb_ep_enable -1 syz, C 24 7m 10d 0/2 upstream: reported C repro on 2026/07/31 21:09

Sample crash report:
------------[ cut here ]------------
usb_ep_enable: ep129 (ep1in-bulk) has maxpacket 0
WARNING: CPU: 0 PID: 0 at drivers/usb/gadget/udc/core.c:108 usb_ep_enable+0x25f/0x440 drivers/usb/gadget/udc/core.c:107
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:usb_ep_enable+0x25f/0x440 drivers/usb/gadget/udc/core.c:107
Code: 49 8b 0e 48 c7 c0 80 27 d5 8a 49 c7 c0 a0 27 d5 8a 4c 0f 44 c0 48 c7 c7 40 27 d5 8a 48 c7 c6 1d 96 e1 8b 89 ea e8 c1 94 7f 03 <0f> 0b e9 e1 fe ff ff e8 95 67 43 fb 49 bc 00 00 00 00 00 fc ff df
RSP: 0018:ffffc900000076a8 EFLAGS: 00010046
RAX: bcba74ca5ada9800 RBX: ffff8881486f00e0 RCX: ffffffff8c0bc480
RDX: 0000000000000100 RSI: 0000000000000103 RDI: 0000000000000000
RBP: 0000000000000081 R08: ffff8880b902795b R09: 1ffff11017204f2b
R10: dffffc0000000000 R11: ffffed1017204f2c R12: dffffc0000000000
R13: ffff8881486f010d R14: ffff8881486f00e8 R15: ffff88802a38bb3a
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffda3284e54 CR3: 0000000029c63000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 hidg_set_alt+0x126/0xa00 drivers/usb/gadget/function/f_hid.c:822
 set_config+0x734/0xfa0 drivers/usb/gadget/composite.c:972
 composite_setup+0x1999/0x2b60 drivers/usb/gadget/composite.c:1878
 configfs_composite_setup+0xc3/0x100 drivers/usb/gadget/configfs.c:1492
 dummy_timer+0x1338/0x33c0 drivers/usb/gadget/udc/dummy_hcd.c:1930
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: b7 48 89 df e8 36 b7 f4 f7 eb ad e8 df ab f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d e7 65 5c 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8c007dc8 EFLAGS: 000002c6
RAX: bcba74ca5ada9800 RBX: ffffffff8c0bc480 RCX: bcba74ca5ada9800
RDX: 0000000000000001 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4200
RBP: ffffffff8c007ef8 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffffffff1800fc4
R13: dffffc0000000000 R14: 1ffffffff1817890 R15: 0000000000000000
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:202 [inline]
 do_idle+0x3a1/0x650 kernel/sched/idle.c:326
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:424
 start_kernel+0x489/0x540 init/main.c:1153
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>
----------------
Code disassembly (best guess):
   0:	b7 48                	mov    $0x48,%bh
   2:	89 df                	mov    %ebx,%edi
   4:	e8 36 b7 f4 f7       	call   0xf7f4b73f
   9:	eb ad                	jmp    0xffffffb8
   b:	e8 df ab f6 ff       	call   0xfff6abef
  10:	00 00                	add    %al,(%rax)
  12:	cc                   	int3
  13:	cc                   	int3
  14:	00 00                	add    %al,(%rax)
  16:	cc                   	int3
  17:	cc                   	int3
  18:	00 00                	add    %al,(%rax)
  1a:	cc                   	int3
  1b:	cc                   	int3
  1c:	00 00                	add    %al,(%rax)
  1e:	cc                   	int3
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d e7 65 5c 00 	verw   0x5c65e7(%rip)        # 0x5c660f
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	c3                   	ret <-- trapping instruction
  2b:	0f 1f 40 00          	nopl   0x0(%rax)
  2f:	41 57                	push   %r15
  31:	41 56                	push   %r14
  33:	53                   	push   %rbx
  34:	49 be 00 00 00 00 00 	movabs $0xdffffc0000000000,%r14
  3b:	fc ff df
  3e:	65                   	gs
  3f:	48                   	rex.W

Crashes (44):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/01 01:05 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/11 00:58 linux-5.15.y aabd761612db 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/10 08:52 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:35 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:32 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:30 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:27 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:25 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:22 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:20 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 23:16 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/08 09:33 linux-5.15.y aabd761612db 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/02 00:23 linux-5.15.y 6e2fd6534337 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/02 00:22 linux-5.15.y 6e2fd6534337 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/02 00:20 linux-5.15.y 6e2fd6534337 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/02 00:20 linux-5.15.y 6e2fd6534337 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/02 00:17 linux-5.15.y 6e2fd6534337 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/08/02 00:17 linux-5.15.y 6e2fd6534337 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:38 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:34 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:34 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:32 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:32 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:32 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:31 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:30 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:29 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:29 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:29 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:29 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:28 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:27 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:27 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:27 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:25 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:25 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:24 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:24 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:22 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:20 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:19 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
2026/07/31 20:17 linux-5.15.y 6e2fd6534337 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in usb_ep_enable
* Struck through repros no longer work on HEAD.