general protection fault in usb_ep_alloc_request

Status: moderation: reported on 2026/09/16 15:32
Subsystems: usb
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+2a7ce560c30c4ca3bc22@syzkaller.appspotmail.com
First crash: 4d02h, last: 3d18h
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ID Workflow Result Correct Bug Created Started Finished Revision
cf8c2890 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ general protection fault in usb_ep_alloc_request 2026/09/14 01:29 2026/09/14 01:29 2026/09/14 02:13 70a60e12

Sample crash report:
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 1
CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x410/0x560 lib/fault-inject.c:174
 should_failslab+0xa8/0x100 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4638 [inline]
 slab_alloc_node mm/slub.c:4974 [inline]
 __kmalloc_cache_noprof+0xa3/0x600 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 dummy_alloc_request+0x7f/0x130 drivers/usb/gadget/udc/dummy_hcd.c:693
 usb_ep_alloc_request+0x67/0x280 drivers/usb/gadget/udc/core.c:197
 gadget_bind+0xec/0x610 drivers/usb/gadget/legacy/raw_gadget.c:294
 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x339/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x345/0x670 drivers/base/bus.c:763
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1752
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:596 [inline]
 raw_ioctl+0x1541/0x41c0 drivers/usb/gadget/legacy/raw_gadget.c:1307
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f39ffd9ddeb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f3a00c3aec0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f39ffd9ddeb
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000005
RBP: 00007f3a00c3bf90 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000200000000100 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:do_perf_trace_udc_log_req drivers/usb/gadget/udc/trace.h:242 [inline]
RIP: 0010:perf_trace_udc_log_req+0x30a/0x850 drivers/usb/gadget/udc/trace.h:223
Code: c6 3f 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 18 03 00 00 41 c6 06 00 48 8b 54 24 18 4c 8d 72 10 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 12 03 00 00 45 8b 26 4d 8d 77 0c 4c 89
RSP: 0018:ffffc9000f0876a0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffffe8ffffc4ff00 RCX: 0000000000000065
RDX: 0000000000000000 RSI: ffffffff8cd37c40 RDI: ffffe8ffffc4ff40
RBP: ffffc9000f087788 R08: 0000000000000070 R09: 0000000000000030
R10: dffffc0000000000 R11: fffff91ffff89fe9 R12: 0000000000000004
R13: dffffc0000000000 R14: 0000000000000010 R15: ffffe8ffffc4ff00
FS:  00007f3a00c3d6c0(0000) GS:ffff88808c2c6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f39ffd87780 CR3: 000000003ec4c000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __do_trace_usb_ep_alloc_request drivers/usb/gadget/udc/trace.h:264 [inline]
 trace_usb_ep_alloc_request drivers/usb/gadget/udc/trace.h:264 [inline]
 usb_ep_alloc_request+0x23b/0x280 drivers/usb/gadget/udc/core.c:202
 gadget_bind+0xec/0x610 drivers/usb/gadget/legacy/raw_gadget.c:294
 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x339/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x345/0x670 drivers/base/bus.c:763
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1752
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:596 [inline]
 raw_ioctl+0x1541/0x41c0 drivers/usb/gadget/legacy/raw_gadget.c:1307
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f39ffd9ddeb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f3a00c3aec0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f39ffd9ddeb
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000005
RBP: 00007f3a00c3bf90 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000200000000100 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_perf_trace_udc_log_req drivers/usb/gadget/udc/trace.h:242 [inline]
RIP: 0010:perf_trace_udc_log_req+0x30a/0x850 drivers/usb/gadget/udc/trace.h:223
Code: c6 3f 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 18 03 00 00 41 c6 06 00 48 8b 54 24 18 4c 8d 72 10 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 12 03 00 00 45 8b 26 4d 8d 77 0c 4c 89
RSP: 0018:ffffc9000f0876a0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffffe8ffffc4ff00 RCX: 0000000000000065
RDX: 0000000000000000 RSI: ffffffff8cd37c40 RDI: ffffe8ffffc4ff40
RBP: ffffc9000f087788 R08: 0000000000000070 R09: 0000000000000030
R10: dffffc0000000000 R11: fffff91ffff89fe9 R12: 0000000000000004
R13: dffffc0000000000 R14: 0000000000000010 R15: ffffe8ffffc4ff00
FS:  00007f3a00c3d6c0(0000) GS:ffff88808c2c6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f39ffd87780 CR3: 000000003ec4c000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	4c 89 f0             	mov    %r14,%rax
   3:	48 c1 e8 03          	shr    $0x3,%rax
   7:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
   c:	84 c0                	test   %al,%al
   e:	0f 85 18 03 00 00    	jne    0x32c
  14:	41 c6 06 00          	movb   $0x0,(%r14)
  18:	48 8b 54 24 18       	mov    0x18(%rsp),%rdx
  1d:	4c 8d 72 10          	lea    0x10(%rdx),%r14
  21:	4c 89 f0             	mov    %r14,%rax
  24:	48 c1 e8 03          	shr    $0x3,%rax
* 28:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2d:	84 c0                	test   %al,%al
  2f:	0f 85 12 03 00 00    	jne    0x347
  35:	45 8b 26             	mov    (%r14),%r12d
  38:	4d 8d 77 0c          	lea    0xc(%r15),%r14
  3c:	4c                   	rex.WR
  3d:	89                   	.byte 0x89

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/13 00:06 upstream 5225b8eec4c9 70a60e12 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in usb_ep_alloc_request
2026/09/12 15:29 upstream 5225b8eec4c9 70a60e12 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in usb_ep_alloc_request
* Struck through repros no longer work on HEAD.