BUG: using smp_processor_id() in preemptible code in tx_complete

Status: upstream: reported C repro on 2026/08/01 00:02
Subsystems: usb net
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+04cd90bb99c6ef81a65d@syzkaller.appspotmail.com
Fix commit: 95a5c641fc7b usbnet: fix smp_processor_id() use in preemptible context
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-upstream-gce-arm64 ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root]
First crash: 94d, last: 62d
▶ ▼ ✨ AI Patch Versions (1)
Version Stage Reported Report Link Job
1 moderation 2026/08/08 19:43 Discussion 53c3fa68-e0fd-43a3-8fe6-832fabf5b714
▶ ▼ ✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision
53c3fa68 patching ❓ BUG: using smp_processor_id() in preemptible code in tx_complete 2026/08/08 09:52 2026/08/08 18:00 2026/08/08 19:43 5d63f80b
6a0f2f8d repro-c Reproduced: ✅ ❓ BUG: using smp_processor_id() in preemptible code in tx_complete 2026/08/07 13:51 2026/08/07 16:49 2026/08/07 17:09 e4ef95d6
a915d992 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ✅ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ BUG: using smp_processor_id() in preemptible code in tx_complete 2026/08/01 02:00 2026/08/01 02:00 2026/08/01 02:50 7664cf44
▶ ▼ Discussions (7)
Title Replies (including bot) Last reply
[PATCH net v6] usbnet: fix smp_processor_id() use in preemptible context 22 (22) 2026/10/16 18:56
[PATCH net] usbnet: fix EVENT_RX_PAUSED race in usbnet_skb_return() 5 (5) 2026/10/08 13:56
[PATCH net v5] usbnet: fix smp_processor_id() use in preemptible context 2 (2) 2026/10/04 21:00
[PATCH net v4] usbnet: fix smp_processor_id() use in preemptible context 3 (3) 2026/09/10 09:01
[PATCH] usbnet: fix smp_processor_id() use in preemptible context 5 (5) 2026/09/08 03:43
[PATCH 1/2] usbnet: fix smp_processor_id() use in preemptible context 1 (1) 2026/09/03 16:46
[syzbot] [net?] [usb?] BUG: using smp_processor_id() in preemptible code in tx_complete 0 (2) 2026/08/08 09:48
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/08/31 17:00 14m retest repro upstream report job log log
2026/08/08 08:26 20m nogikh@google.com upstream report log

Sample crash report:
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

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/08 09:47 upstream a59f57e2aa12 abc81b93 .config console log report C ci-qemu-upstream BUG: using smp_processor_id() in preemptible code in tx_complete
2026/07/30 11:01 upstream 11028ab62899 abc81b93 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream BUG: using smp_processor_id() in preemptible code in tx_complete
2026/08/17 11:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in tx_complete
* Struck through repros no longer work on HEAD.