syzbot
general protection fault in dummy_set_selfpowered
Status:
upstream: reported on 2026/07/25 01:11
Reported-by: syzbot+e6aa07b89235491b9670@syzkaller.appspotmail.com
First crash: 8d01h, last: 7h37m
Sample crash report:
syzkaller0: entered promiscuous mode
syzkaller0: entered allmulticast mode
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 7571 Comm: syz.2.435 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:dummy_set_selfpowered+0xbb/0x150 drivers/usb/gadget/udc/dummy_hcd.c:887
Code: 94 c0 4d 8d b4 c6 80 06 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf ac 25 fb 4d 8b 3e 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 a6 ac 25 fb 41 be 78 12 00 00 4d
RSP: 0018:ffffc9000b61f7e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff888023c75a00 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 0000000000000003 R08: ffff888019e458df R09: 1ffff110033c8b1b
R10: dffffc0000000000 R11: ffffed10033c8b1c R12: dffffc0000000000
R13: ffff88807a2b4530 R14: ffff88814179d280 R15: 0000000000000000
FS: 00007fb6ee1f66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe2ec3e3000 CR3: 000000001b783000 CR4: 00000000003506f0
Call Trace:
<TASK>
usb_gadget_set_selfpowered+0x6e/0x230 drivers/usb/gadget/udc/core.c:578
composite_dev_prepare+0x2fa/0x320 drivers/usb/gadget/composite.c:2464
configfs_composite_bind+0xa1/0x13f0 drivers/usb/gadget/configfs.c:1699
gadget_bind_driver+0x2b3/0x770 drivers/usb/gadget/udc/core.c:1651
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x247/0xae0 drivers/base/dd.c:717
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
__driver_attach+0x444/0x6d0 drivers/base/dd.c:1295
bus_for_each_dev+0x235/0x2b0 drivers/base/bus.c:370
bus_add_driver+0x340/0x630 drivers/base/bus.c:723
driver_register+0x23a/0x310 drivers/base/driver.c:246
usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1730
gadget_dev_desc_UDC_store+0x1c7/0x2e0 drivers/usb/gadget/configfs.c:300
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6eff9e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb6ee1f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb6f0225fa0 RCX: 00007fb6eff9e019
RDX: 000000000000000c RSI: 0000200000001100 RDI: 000000000000000a
RBP: 00007fb6f003500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6f0226038 R14: 00007fb6f0225fa0 R15: 00007ffe913f2b28
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dummy_set_selfpowered+0xbb/0x150 drivers/usb/gadget/udc/dummy_hcd.c:887
Code: 94 c0 4d 8d b4 c6 80 06 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf ac 25 fb 4d 8b 3e 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 a6 ac 25 fb 41 be 78 12 00 00 4d
RSP: 0018:ffffc9000b61f7e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff888023c75a00 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 0000000000000003 R08: ffff888019e458df R09: 1ffff110033c8b1b
R10: dffffc0000000000 R11: ffffed10033c8b1c R12: dffffc0000000000
R13: ffff88807a2b4530 R14: ffff88814179d280 R15: 0000000000000000
FS: 00007fb6ee1f66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b4a9ef2f8 CR3: 000000001b783000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
0: 94 xchg %eax,%esp
1: c0 4d 8d b4 rorb $0xb4,-0x73(%rbp)
5: c6 80 06 00 00 4c 89 movb $0x89,0x4c000006(%rax)
c: f0 48 c1 e8 03 lock shr $0x3,%rax
11: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
16: 74 08 je 0x20
18: 4c 89 f7 mov %r14,%rdi
1b: e8 bf ac 25 fb call 0xfb25acdf
20: 4d 8b 3e mov (%r14),%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ff mov %r15,%rdi
34: e8 a6 ac 25 fb call 0xfb25acdf
39: 41 be 78 12 00 00 mov $0x1278,%r14d
3f: 4d rex.WRB
* Struck through repros no longer work on HEAD.