[syzbot] [usb?] general protection fault in dummy_timer (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 237d4e0f4113 usb: typec: tcpm: Add support for sink-bc12-c..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=114e76e8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=358c1689354aeef3
dashboard link: https://syzkaller.appspot.com/bug?extid=faf3a6cf579fc65591ca
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1d16b8e77d72/disk-237d4e0f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9636263bfc8f/vmlinux-237d4e0f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/36d0ba4d90fb/bzImage-237d4e0f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+faf3a6...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000040: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000200-0x0000000000000207]
CPU: 1 UID: 0 PID: 13433 Comm: syz-executor Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:strcmp+0x5b/0xb0 lib/string.c:266
Code: fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 38 d0 7f 04 84 c0 75 58 0f b6 6b ff 4c 8d 66 01 48 89 f0 48 89 f2 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 2c 41 3a 6c 24 ff 74 ae 19 c0
RSP: 0018:ffffc900001b8850 EFLAGS: 00010046
RAX: 0000000000000040 RBX: ffffffff8746fac1 RCX: ffffffff8fb08b60
RDX: 0000000000000000 RSI: 0000000000000200 RDI: ffffffff8746fac0
RBP: 0000000000000066 R08: 0000000000000001 R09: dffffc0000000000
R10: ffffffff8fb08b70 R11: ffffffff8fb08b60 R12: 0000000000000201
R13: dffffc0000000000 R14: 00000000000001f2 R15: ffffffff934a7980
FS: 0000555591f43500(0000) GS:ffff8881f5900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c30aef3 CR3: 00000001166a8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
count_matching_names kernel/locking/lockdep.c:875 [inline]
register_lock_class+0x63b/0x1240 kernel/locking/lockdep.c:1340
__lock_acquire+0x135/0x3ce0 kernel/locking/lockdep.c:5077
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
complete_with_flags kernel/sched/completion.c:20 [inline]
complete+0x1d/0x200 kernel/sched/completion.c:47
transfer drivers/usb/gadget/udc/dummy_hcd.c:1522 [inline]
dummy_timer+0x1c04/0x3930 drivers/usb/gadget/udc/dummy_hcd.c:1977
__run_hrtimer kernel/time/hrtimer.c:1691 [inline]
__hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1755
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1772
handle_softirqs+0x206/0x8d0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xac/0x110 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5790
Code: b8 ff ff ff ff 65 0f c1 05 90 1f cf 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7
RSP: 0018:ffffc9001499f500 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 1ffff92002933ea1 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff8727f520 RDI: ffffffff8746ec80
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff1f559b4
R10: ffffffff8faacda7 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff88ebb140 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
page_ext_get+0x3a/0x310 mm/page_ext.c:525
page_table_check_set mm/page_table_check.c:114 [inline]
page_table_check_set+0x285/0x9c0 mm/page_table_check.c:102
__page_table_check_ptes_set+0x44c/0x710 mm/page_table_check.c:225
page_table_check_ptes_set include/linux/page_table_check.h:74 [inline]
set_ptes include/linux/pgtable.h:267 [inline]
__copy_present_ptes mm/memory.c:969 [inline]
copy_present_ptes+0xc03/0x3540 mm/memory.c:1052
copy_pte_range mm/memory.c:1167 [inline]
copy_pmd_range mm/memory.c:1255 [inline]
copy_pud_range mm/memory.c:1292 [inline]
copy_p4d_range mm/memory.c:1316 [inline]
copy_page_range+0xbd7/0x2420 mm/memory.c:1414
dup_mmap kernel/fork.c:746 [inline]
dup_mm kernel/fork.c:1675 [inline]
copy_mm kernel/fork.c:1724 [inline]
copy_process+0x8236/0x91e0 kernel/fork.c:2374
kernel_clone+0xfd/0x960 kernel/fork.c:2786
__do_sys_clone+0xba/0x100 kernel/fork.c:2929
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff90ac55093
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc36e1b4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff90ac55093
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000555591f437d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000001091bd R14: 0000000000108c37 R15: 00007ffc36e1b670
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:strcmp+0x5b/0xb0 lib/string.c:266
Code: fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 38 d0 7f 04 84 c0 75 58 0f b6 6b ff 4c 8d 66 01 48 89 f0 48 89 f2 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 2c 41 3a 6c 24 ff 74 ae 19 c0
RSP: 0018:ffffc900001b8850 EFLAGS: 00010046
RAX: 0000000000000040 RBX: ffffffff8746fac1 RCX: ffffffff8fb08b60
RDX: 0000000000000000 RSI: 0000000000000200 RDI: ffffffff8746fac0
RBP: 0000000000000066 R08: 0000000000000001 R09: dffffc0000000000
R10: ffffffff8fb08b70 R11: ffffffff8fb08b60 R12: 0000000000000201
R13: dffffc0000000000 R14: 00000000000001f2 R15: ffffffff934a7980
FS: 0000555591f43500(0000) GS:ffff8881f5900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c30aef3 CR3: 00000001166a8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: fa cli
1: 48 c1 e8 03 shr $0x3,%rax
5: 83 e2 07 and $0x7,%edx
8: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax
d: 38 d0 cmp %dl,%al
f: 7f 04 jg 0x15
11: 84 c0 test %al,%al
13: 75 58 jne 0x6d
15: 0f b6 6b ff movzbl -0x1(%rbx),%ebp
19: 4c 8d 66 01 lea 0x1(%rsi),%r12
1d: 48 89 f0 mov %rsi,%rax
20: 48 89 f2 mov %rsi,%rdx
23: 48 c1 e8 03 shr $0x3,%rax
27: 83 e2 07 and $0x7,%edx
* 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction
2f: 38 d0 cmp %dl,%al
31: 7f 04 jg 0x37
33: 84 c0 test %al,%al
35: 75 2c jne 0x63
37: 41 3a 6c 24 ff cmp -0x1(%r12),%bpl
3c: 74 ae je 0xffffffec
3e: 19 c0 sbb %eax,%eax


---
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 811d22141369 usb: dwc3: exynos: add support for exynos7870

git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing

console output: https://syzkaller.appspot.com/x/log.txt?x=1690e464580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f429368eda610a89

dashboard link: https://syzkaller.appspot.com/bug?extid=faf3a6cf579fc65591ca
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11500697980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c0764bd2a6ef/disk-811d2214.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a8d014106735/vmlinux-811d2214.xz
kernel image: https://storage.googleapis.com/syzbot-assets/80062d83482e/bzImage-811d2214.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+faf3a6...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000060: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000300-0x0000000000000307]
CPU: 0 UID: 0 PID: 7918 Comm: syz-executor Not tainted 6.14.0-rc3-syzkaller-00056-g811d22141369 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:strcmp+0x5b/0xb0 lib/string.c:277

Code: fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 38 d0 7f 04 84 c0 75 58 0f b6 6b ff 4c 8d 66 01 48 89 f0 48 89 f2 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 2c 41 3a 6c 24 ff 74 ae 19 c0

RSP: 0018:ffffc90000007848 EFLAGS: 00010046
RAX: 0000000000000060 RBX: ffffffff8747ce21 RCX: ffffffff8fb2a5e8
RDX: 0000000000000000 RSI: 0000000000000300 RDI: ffffffff8747ce20
RBP: 0000000000000026 R08: 0000000000000001 R09: dffffc0000000000
R10: ffffffff8fb2a5f8 R11: ffffffff8fb2a5e8 R12: 0000000000000301
R13: dffffc0000000000 R14: 00000000000003b1 R15: ffffffff934e19e0
FS: 000055558b609500(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000

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

CR2: 00007f143e94aea2 CR3: 000000012b09c000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>

count_matching_names kernel/locking/lockdep.c:877 [inline]
register_lock_class+0x63b/0x1240 kernel/locking/lockdep.c:1342
__lock_acquire+0x135/0x3c40 kernel/locking/lockdep.c:5103
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851

__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
complete_with_flags kernel/sched/completion.c:20 [inline]
complete+0x1d/0x200 kernel/sched/completion.c:47

transfer drivers/usb/gadget/udc/dummy_hcd.c:1523 [inline]
dummy_timer+0x1c37/0x3960 drivers/usb/gadget/udc/dummy_hcd.c:1978
__run_hrtimer kernel/time/hrtimer.c:1801 [inline]
__hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1865
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1882
handle_softirqs+0x206/0x8d0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0xfa/0x160 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678

instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

RIP: 0010:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5816
Code: b8 ff ff ff ff 65 0f c1 05 90 2f aa 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7
RSP: 0018:ffffc9000446fc98 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 1ffff9200088df94 RCX: 00000000521e9cf7
RDX: 0000000000000001 RSI: ffffffff87281ac0 RDI: ffffffff8747c1a0
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff1f5cdc0
R10: ffffffff8fae6e07 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff88ebe3c0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:941 [inline]
fd_install+0xc0/0x750 fs/file.c:639
do_sys_openat2+0x1a4/0x1e0 fs/open.c:1433
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1454

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f143e88ba51
Code: 75 57 89 f0 25 00 00 41 00 3d 00 00 41 00 74 49 80 3d fa 1a 1f 00 00 74 6d 89 da 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 93 00 00 00 48 8b 54 24 28 64 48 2b 14 25
RSP: 002b:00007ffc6205c990 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000080001 RCX: 00007f143e88ba51
RDX: 0000000000080001 RSI: 00007f143e90fadc RDI: 00000000ffffff9c
RBP: 00007f143e90fadc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffc6205ca30 R14: 00000000000aeedc R15: 00007ffc6205cfa0

</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---

RIP: 0010:strcmp+0x5b/0xb0 lib/string.c:277

Code: fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 38 d0 7f 04 84 c0 75 58 0f b6 6b ff 4c 8d 66 01 48 89 f0 48 89 f2 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 2c 41 3a 6c 24 ff 74 ae 19 c0

RSP: 0018:ffffc90000007848 EFLAGS: 00010046
RAX: 0000000000000060 RBX: ffffffff8747ce21 RCX: ffffffff8fb2a5e8
RDX: 0000000000000000 RSI: 0000000000000300 RDI: ffffffff8747ce20
RBP: 0000000000000026 R08: 0000000000000001 R09: dffffc0000000000
R10: ffffffff8fb2a5f8 R11: ffffffff8fb2a5e8 R12: 0000000000000301
R13: dffffc0000000000 R14: 00000000000003b1 R15: ffffffff934e19e0
FS: 000055558b609500(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000

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

CR2: 00007f143e94aea2 CR3: 000000012b09c000 CR4: 00000000003506f0

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: a975094bf98c Merge tag 'exfat-for-7.2-rc1' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=125ea50e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=26c7945305cfa3b1
dashboard link: https://syzkaller.appspot.com/bug?extid=faf3a6cf579fc65591ca
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16750356580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132d4586580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-a975094b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e4435d766294/vmlinux-a975094b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c6c16f744e16/bzImage-a975094b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+faf3a6...@syzkaller.appspotmail.com

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.h:68:9
index 16382 is out of range for type 'long unsigned int [8]'
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
__ubsan_handle_out_of_bounds+0xcc/0xf0 lib/ubsan.c:455
decode_tail kernel/locking/qspinlock.h:68 [inline]
__pv_queued_spin_lock_slowpath+0xbd7/0xc00 kernel/locking/qspinlock.c:285
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x1e0/0x260 kernel/locking/spinlock_debug.c:116
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:166
complete_with_flags kernel/sched/completion.c:25 [inline]
complete+0x1d/0x200 kernel/sched/completion.c:52
transfer drivers/usb/gadget/udc/dummy_hcd.c:1527 [inline]
dummy_timer+0x121c/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:1989
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 96 88 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 d8 14 00 fb f4 <e9> fc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000177e00 EFLAGS: 00000246
RAX: 0000000000400dbc RBX: ffff88801e6c2540 RCX: ffffffff8b96c2d5
RDX: 0000000000000001 RSI: ffffffff8c1d2700 RDI: ffffffff81de3aa7
RBP: ffffed1003cd84a8 R08: 0000000000000000 R09: ffffed100d4a678d
R10: ffff88806a533c6b R11: ffffffff81d50f9c R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff9200002efc4 R15: dffffc0000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x158
</TASK>
---[ end trace ]---

----------------
Code disassembly (best guess):

0: 96 xchg %eax,%esi
1: 88 02 mov %al,(%rdx)
3: c3 ret
4: cc int3
5: cc int3
6: cc int3
7: cc int3
8: 0f 1f 00 nopl (%rax)
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: f3 0f 1e fa endbr64
1f: eb 07 jmp 0x28
21: 0f 00 2d 23 d8 14 00 verw 0x14d823(%rip) # 0x14d84b
28: fb sti
29: f4 hlt
* 2a: e9 fc 48 03 00 jmp 0x3492b <-- trapping instruction
2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
36: 00 00 00
39: 66 90 xchg %ax,%ax
3b: 90 nop
3c: 90 nop
3d: 90 nop
3e: 90 nop
3f: 90 nop

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: [PATCH] usb: gadget: dummy_hcd: prevent fifo_req reuse during giveback
Author: wangjin...@gmail.com

#syz test
dummy_hcd embeds a single shared usb_request (dum->fifo_req) that the
"emulated single-request FIFO" fast-path in dummy_queue() reuses for
small IN transfers: it copies the caller's request into it
(req->req = *_req) and queues it, treating list_empty(&fifo_req.queue)
as "the slot is free".

The completion side (dummy_timer/transfer/nuke/dummy_dequeue) follows
the standard pattern: list_del_init(&req->queue) unlinks the request,
then the lock is dropped and usb_gadget_giveback_request() invokes
req->complete(). But list_del_init() makes fifo_req.queue look empty
*before* the completion callback returns, so a concurrent dummy_queue()
on another CPU sees the slot as free, reuses fifo_req and runs
req->req = *_req -- overwriting req->complete while dummy_timer is
mid-calling it. The indirect call then jumps to a clobbered pointer,
causing a general protection fault / page fault in dummy_timer
(syzkaller extid faf3a6cf579fc65591ca). The clobbering write is an
in-bounds memcpy on a live shared object, so KASAN cannot flag it.

Add a fifo_req_busy bit, set across the lockless giveback window via a
dummy_giveback() helper used at all four gadget-request giveback sites,
and require !fifo_req_busy in the FIFO fast-path guard so the shared
slot cannot be reused until its completion callback has returned.

Reported-by: syzbot+faf3a6...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=faf3a6cf579fc65591ca
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: sta...@vger.kernel.org
Signed-off-by: Jinchao Wang <wangjin...@gmail.com>
---
drivers/usb/gadget/udc/dummy_hcd.c | 40 +++++++++++++++++++++---------
1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index f47903461ed5..fce3c3ba7a63 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -278,6 +278,7 @@ struct dummy {
unsigned ints_enabled:1;
unsigned udc_suspended:1;
unsigned pullup:1;
+ unsigned fifo_req_busy:1;

/*
* HOST side support
@@ -330,6 +331,28 @@ static inline struct dummy *gadget_dev_to_dummy(struct device *dev)
/* DEVICE/GADGET SIDE UTILITY ROUTINES */

/* called with spinlock held */
+/*
+ * Give back a gadget request with dum->lock dropped around the callback.
+ * If @req is the shared fifo_req, mark it busy across the callback so
+ * dummy_queue()'s FIFO fast-path (keyed on list_empty(&fifo_req.queue))
+ * cannot reuse it mid-giveback: list_del_init() already made the queue look
+ * empty, but the request is in flight until the completion callback returns.
+ * Caller holds dum->lock and has already done list_del_init() + status.
+ */
+static void dummy_giveback(struct dummy *dum, struct usb_ep *_ep,
+ struct dummy_request *req)
+{
+ bool fifo = req == &dum->fifo_req;
+
+ if (fifo)
+ dum->fifo_req_busy = 1;
+ spin_unlock(&dum->lock);
+ usb_gadget_giveback_request(_ep, &req->req);
+ spin_lock(&dum->lock);
+ if (fifo)
+ dum->fifo_req_busy = 0;
+}
+
static void nuke(struct dummy *dum, struct dummy_ep *ep)
{
while (!list_empty(&ep->queue)) {
@@ -339,9 +362,7 @@ static void nuke(struct dummy *dum, struct dummy_ep *ep)
list_del_init(&req->queue);
req->req.status = -ESHUTDOWN;

- spin_unlock(&dum->lock);
- usb_gadget_giveback_request(&ep->ep, &req->req);
- spin_lock(&dum->lock);
+ dummy_giveback(dum, &ep->ep, req);
}
}

@@ -729,6 +750,7 @@ static int dummy_queue(struct usb_ep *_ep, struct usb_request *_req,
/* implement an emulated single-request FIFO */
if (ep->desc && (ep->desc->bEndpointAddress & USB_DIR_IN) &&
list_empty(&dum->fifo_req.queue) &&
+ !dum->fifo_req_busy &&
list_empty(&ep->queue) &&
_req->length <= FIFO_SIZE) {
req = &dum->fifo_req;
@@ -785,9 +807,7 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
dev_dbg(udc_dev(dum),
"dequeued req %p from %s, len %d buf %p\n",
req, _ep->name, _req->length, _req->buf);
- spin_unlock(&dum->lock);
- usb_gadget_giveback_request(_ep, _req);
- spin_lock(&dum->lock);
+ dummy_giveback(dum, _ep, req);
}
spin_unlock_irqrestore(&dum->lock, flags);
return retval;
@@ -1523,9 +1543,7 @@ static int transfer(struct dummy_hcd *dum_hcd, struct urb *urb,
if (req->req.status != -EINPROGRESS) {
list_del_init(&req->queue);

- spin_unlock(&dum->lock);
- usb_gadget_giveback_request(&ep->ep, &req->req);
- spin_lock(&dum->lock);
+ dummy_giveback(dum, &ep->ep, req);

/* requests might have been unlinked... */
rescan = 1;
@@ -1910,9 +1928,7 @@ static enum hrtimer_restart dummy_timer(struct hrtimer *t)
dev_dbg(udc_dev(dum), "stale req = %p\n",
req);

- spin_unlock(&dum->lock);
- usb_gadget_giveback_request(&ep->ep, &req->req);
- spin_lock(&dum->lock);
+ dummy_giveback(dum, &ep->ep, req);
ep->already_seen = 0;
goto restart;
}
--
2.53.0