syzbot
WARNING in usb_ep_enable
Status:
premoderation: reported C repro on 2026/07/30 13:40
Reported-by: syzbot+53eb788a470795ed13dd@syzkaller.appspotmail.com
First crash: 5d11h, last: 4d15h
Sample crash report:
------------[ cut here ]------------
usb_ep_enable: ep129 (ep1in-bulk) has maxpacket 0
WARNING: CPU: 0 PID: 110 at drivers/usb/gadget/udc/core.c:123 usb_ep_enable+0x210/0x3c0 drivers/usb/gadget/udc/core.c:122
Modules linked in:
CPU: 0 UID: 0 PID: 110 Comm: udevd Not tainted syzkaller #0 0b31bef96cff8e44f9e14c4f768eb06c85e3b290
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:usb_ep_enable+0x210/0x3c0 drivers/usb/gadget/udc/core.c:122
Code: 4d 00 48 c7 c0 e0 52 6d 86 49 c7 c0 00 53 6d 86 4c 0f 44 c0 48 c7 c7 a0 52 6d 86 48 c7 c6 46 ec 1c 87 44 89 f2 e8 20 c8 4b fd <0f> 0b e9 4c ff ff ff e8 e4 ef ce fd 49 bc 00 00 00 00 00 fc ff df
RSP: 0018:ffffc90000007878 EFLAGS: 00010046
RAX: 84496c1ba7043700 RBX: ffff8881043f40b0 RCX: ffff88810d703900
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000078a0 R08: ffff8881f6e294d3 R09: 1ffff1103edc529a
R10: dffffc0000000000 R11: ffffed103edc529b R12: dffffc0000000000
R13: ffff8881043f40b8 R14: 0000000000000081 R15: ffff8881056eb9ba
FS: 00007f6673e09880(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f557f77183c CR3: 000000010df1a000 CR4: 00000000003526b0
Call Trace:
<IRQ>
hidg_set_alt+0x138/0xa70 drivers/usb/gadget/function/f_hid.c:1057
set_config+0x812/0xd10 drivers/usb/gadget/composite.c:1021
composite_setup+0x1885/0x32f0 drivers/usb/gadget/composite.c:1929
configfs_composite_setup+0xc6/0x110 drivers/usb/gadget/configfs.c:1883
dummy_timer+0x2eee/0x4900 drivers/usb/gadget/udc/dummy_hcd.c:1935
__run_hrtimer kernel/time/hrtimer.c:1757 [inline]
__hrtimer_run_queues+0x3ae/0x8e0 kernel/time/hrtimer.c:1821
hrtimer_run_softirq+0x159/0x560 kernel/time/hrtimer.c:1838
handle_softirqs+0x1aa/0x620 kernel/softirq.c:621
__do_softirq kernel/softirq.c:659 [inline]
invoke_softirq kernel/softirq.c:476 [inline]
__irq_exit_rcu+0x47/0xb0 kernel/softirq.c:708
irq_exit_rcu+0xd/0x30 kernel/softirq.c:720
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x82/0x90 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702
RIP: 0010:arch_stack_walk+0x13f/0x170 arch/x86/kernel/stacktrace.c:24
Code: 4d 89 f3 41 ba 66 cb 4f e4 45 03 53 f1 74 02 0f 0b 2e e8 d8 04 c2 1e 84 c0 74 11 4c 89 ff e8 88 88 06 00 83 bd 78 ff ff ff 00 <75> c1 65 48 8b 04 25 28 00 00 00 48 3b 45 d8 75 12 48 83 c4 68 5b
RSP: 0018:ffffc90000e6f3a8 EFLAGS: 00000202
RAX: 1ffff920001cde01 RBX: ffffc90000e6f460 RCX: 00000000001cde01
RDX: ffffc90000e6f850 RSI: 1ffff920001cde76 RDI: ffffc90000e6f3d0
RBP: ffffc90000e6f430 R08: ffffc90000e6f470 R09: ffffc90000e6f468
R10: 0000000000000004 R11: ffffffff81759ed0 R12: ffff88810d703900
R13: 0000000000000020 R14: ffffffff81759ed0 R15: ffffc90000e6f3a8
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:49 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
__kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
kasan_kmalloc include/linux/kasan.h:261 [inline]
__do_kmalloc_node mm/slub.c:4395 [inline]
__kmalloc_noprof+0x261/0x510 mm/slub.c:4407
kmalloc_noprof include/linux/slab.h:885 [inline]
shmem_initxattrs+0x2a8/0x530 mm/shmem.c:4093
security_inode_init_security+0x431/0x600 security/security.c:1853
shmem_mknod+0xd5/0x200 mm/shmem.c:3695
shmem_create+0x38/0x50 mm/shmem.c:3759
lookup_open fs/namei.c:3603 [inline]
open_last_lookups fs/namei.c:3702 [inline]
path_openat+0x150b/0x35a0 fs/namei.c:3938
do_filp_open+0x1f2/0x440 fs/namei.c:3968
do_sys_openat2+0x134/0x1d0 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_openat fs/open.c:1471 [inline]
__se_sys_openat fs/open.c:1466 [inline]
__x64_sys_openat+0x13a/0x170 fs/open.c:1466
x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f66736a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc856507f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6673e09880 RCX: 00007f66736a7407
RDX: 0000000000080141 RSI: 000055f31d0bf02e RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001a4 R11: 0000000000000202 R12: 00000000ffffffff
R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000
</TASK>
---[ end trace 0000000000000000 ]---
configfs-gadget.g1 gadget.0: Enable IN endpoint FAILED!
----------------
Code disassembly (best guess):
0: 4d 89 f3 mov %r14,%r11
3: 41 ba 66 cb 4f e4 mov $0xe44fcb66,%r10d
9: 45 03 53 f1 add -0xf(%r11),%r10d
d: 74 02 je 0x11
f: 0f 0b ud2
11: 2e e8 d8 04 c2 1e cs call 0x1ec204ef
17: 84 c0 test %al,%al
19: 74 11 je 0x2c
1b: 4c 89 ff mov %r15,%rdi
1e: e8 88 88 06 00 call 0x688ab
23: 83 bd 78 ff ff ff 00 cmpl $0x0,-0x88(%rbp)
* 2a: 75 c1 jne 0xffffffed <-- trapping instruction
2c: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax
33: 00 00
35: 48 3b 45 d8 cmp -0x28(%rbp),%rax
39: 75 12 jne 0x4d
3b: 48 83 c4 68 add $0x68,%rsp
3f: 5b pop %rbx
Struck through repros no longer work on HEAD.