[v5.15] general protection fault in dummy_set_selfpowered

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 674f684f7c61 Linux 5.15.212
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=178ca6b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=9e82e63d823b71764eb6
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f55be2937b89/disk-674f684f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a19fb0ffc049/vmlinux-674f684f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/365d4529a007/bzImage-674f684f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e82e6...@syzkaller.appspotmail.com

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: 6327 Comm: syz.3.625 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:dummy_set_selfpowered+0xb7/0x150 drivers/usb/gadget/udc/dummy_hcd.c:884
Code: 94 c0 4d 8d b4 c6 f8 06 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 13 b4 87 fb 4d 8b 3e 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 fa b3 87 fb 41 be f0 12 00 00 4d
RSP: 0018:ffffc900015afa38 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888025ec9dc0
RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 0000000000000003 R08: ffffffff8c44fd07 R09: 1ffffffff1889fa0
R10: dffffc0000000000 R11: fffffbfff1889fa1 R12: dffffc0000000000
R13: ffff8880256924b8 R14: ffff888147a952f8 R15: 0000000000000000
FS: 00007fa3c53926c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000600b0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
usb_gadget_set_selfpowered+0x6a/0x230 drivers/usb/gadget/udc/core.c:561
composite_dev_prepare+0x2f3/0x310 drivers/usb/gadget/composite.c:2323
configfs_composite_bind+0xa1/0xf60 drivers/usb/gadget/configfs.c:1310
udc_bind_to_driver+0x203/0x5f0 drivers/usb/gadget/udc/core.c:1574
usb_gadget_probe_driver+0x1fb/0x380 drivers/usb/gadget/udc/core.c:1637
gadget_dev_desc_UDC_store+0x1ba/0x2e0 drivers/usb/gadget/configfs.c:289
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa3c7139e99
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:00007fa3c5392028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa3c73c1fa0 RCX: 00007fa3c7139e99
RDX: 000000000000000b RSI: 0000200000000880 RDI: 0000000000000003
RBP: 00007fa3c71cfeaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3c73c2038 R14: 00007fa3c73c1fa0 R15: 00007ffd7d384418
</TASK>
Modules linked in:
---[ end trace ca2a781287e9de06 ]---
RIP: 0010:dummy_set_selfpowered+0xb7/0x150 drivers/usb/gadget/udc/dummy_hcd.c:884
Code: 94 c0 4d 8d b4 c6 f8 06 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 13 b4 87 fb 4d 8b 3e 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 fa b3 87 fb 41 be f0 12 00 00 4d
RSP: 0018:ffffc900015afa38 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888025ec9dc0
RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 0000000000000003 R08: ffffffff8c44fd07 R09: 1ffffffff1889fa0
R10: dffffc0000000000 R11: fffffbfff1889fa1 R12: dffffc0000000000
R13: ffff8880256924b8 R14: ffff888147a952f8 R15: 0000000000000000
FS: 00007fa3c53926c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 00000000600b0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 94 xchg %eax,%esp
1: c0 4d 8d b4 rorb $0xb4,-0x73(%rbp)
5: c6 f8 06 xabort $0x6
8: 00 00 add %al,(%rax)
a: 4c 89 f0 mov %r14,%rax
d: 48 c1 e8 03 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 13 b4 87 fb call 0xfb87b433
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 fa b3 87 fb call 0xfb87b433
39: 41 be f0 12 00 00 mov $0x12f0,%r14d
3f: 4d rex.WRB


---
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[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: da47cbc25466 Linux 6.6.144
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15c0109e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=e6aa07b89235491b9670

compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:

disk image: https://storage.googleapis.com/syzbot-assets/6988639f2873/disk-da47cbc2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/796fa32e7777/vmlinux-da47cbc2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/480ca9c40b5c/bzImage-da47cbc2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+e6aa07...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]

CPU: 1 PID: 8549 Comm: syz.1.661 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026

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 7f fa 25 fb 4d 8b 3e 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 66 fa 25 fb 41 be 78 12 00 00 4d
RSP: 0018:ffffc90003af77e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff888029960000 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 0000000000000003 R08: ffff888019e458df R09: 1ffff110033c8b1b
R10: dffffc0000000000 R11: ffffed10033c8b1c R12: dffffc0000000000
R13: ffff888079a46530 R14: ffff888025191280 R15: 0000000000000000
FS: 00007f8e702626c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000000000000000 CR3: 000000006e47f000 CR4: 00000000003506e0
Call Trace:
<TASK>
usb_gadget_set_selfpowered+0x6e/0x230 drivers/usb/gadget/udc/core.c:576
composite_dev_prepare+0x2fa/0x320 drivers/usb/gadget/composite.c:2463
configfs_composite_bind+0xa1/0x13f0 drivers/usb/gadget/configfs.c:1699
gadget_bind_driver+0x2b3/0x770 drivers/usb/gadget/udc/core.c:1624
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x247/0xae0 drivers/base/dd.c:718
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:880
driver_probe_device+0x4f/0x420 drivers/base/dd.c:910
__driver_attach+0x444/0x6d0 drivers/base/dd.c:1296
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:1703
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: 0033:0x7f8e6f39de99

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:00007f8e70262028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f8e6f625fa0 RCX: 00007f8e6f39de99
RDX: 000000000000000b RSI: 0000200000000e00 RDI: 0000000000000004
RBP: 00007f8e6f433eaf R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007f8e6f626038 R14: 00007f8e6f625fa0 R15: 00007ffe4da76e88
</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 7f fa 25 fb 4d 8b 3e 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 66 fa 25 fb 41 be 78 12 00 00 4d
RSP: 0018:ffffc90003af77e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff888029960000 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 0000000000000003 R08: ffff888019e458df R09: 1ffff110033c8b1b
R10: dffffc0000000000 R11: ffffed10033c8b1c R12: dffffc0000000000
R13: ffff888079a46530 R14: ffff888025191280 R15: 0000000000000000
FS: 00007f8e702626c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f98a4ded2f8 CR3: 000000006e47f000 CR4: 00000000003506f0

----------------
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 7f fa 25 fb call 0xfb25fa9f

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 66 fa 25 fb call 0xfb25fa9f
39: 41 be 78 12 00 00 mov $0x1278,%r14d