From: syzbot <syzbot+04cd90bb99c6ef81a65d@syzkaller.appspotmail.com>
To: andrew@lunn.ch, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, netdev@vger.kernel.org,
oneukum@suse.com, pabeni@redhat.com,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [net?] [usb?] BUG: using smp_processor_id() in preemptible code in tx_complete
Date: Sat, 08 Aug 2026 02:48:22 -0700 [thread overview]
Message-ID: <6a76fb66.b50370da.49fe0.0025.GAE@google.com> (raw)
In-Reply-To: <6a6d379a.2d659fcc.1d46f5.01a8.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: a59f57e2aa12 Merge tag 'watchdog-for-v7.2-rc7' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=127defb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d07fbc6821d72a61
dashboard link: https://syzkaller.appspot.com/bug?extid=04cd90bb99c6ef81a65d
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17106fb9580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+04cd90bb99c6ef81a65d@syzkaller.appspotmail.com
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 2 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 1 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 3 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 0 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 0 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 0 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 2 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
BUG: using smp_processor_id() in preemptible [00000000] code: vhci_rx/6048
caller is tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
CPU: 3 UID: 0 PID: 6048 Comm: vhci_rx 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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
tx_complete+0x237/0x770 drivers/net/usb/usbnet.c:1301
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
vhci_recv_ret_submit drivers/usb/usbip/vhci_rx.c:107 [inline]
vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:242 [inline]
vhci_rx_loop+0x60e/0xa60 drivers/usb/usbip/vhci_rx.c:265
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
vhci_hcd: connection reset by peer
---
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.
prev parent reply other threads:[~2026-08-08 9:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-01 0:02 [syzbot] [net?] [usb?] BUG: using smp_processor_id() in preemptible code in tx_complete syzbot
2026-08-08 9:48 ` syzbot [this message]
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