CVE-2025-40164

In the Linux kernel, the following vulnerability has been resolved:

usbnet: Fix using smpprocessorid() in preemptible code warnings

Syzbot reported the following warning:

BUG: using smpprocessorid() in preemptible [00000000] code: dhcpcd/2879 caller is usbnetskbreturn+0x74/0x490 drivers/net/usb/usbnet.c:331 CPU: 1 UID: 0 PID: 2879 Comm: dhcpcd Not tainted 6.15.0-rc4-syzkaller-00098-g615dca38c2ea #0 PREEMPT(voluntary) Call Trace: <TASK> __dumpstack lib/dumpstack.c:94 [inline] dump_stacklvl+0x16c/0x1f0 lib/dumpstack.c:120 checkpreemptiondisabled+0xd0/0xe0 lib/smpprocessorid.c:49 usbnetskbreturn+0x74/0x490 drivers/net/usb/usbnet.c:331 usbnetresumerx+0x4b/0x170 drivers/net/usb/usbnet.c:708 usbnetchangemtu+0x1be/0x220 drivers/net/usb/usbnet.c:417 __devsetmtu net/core/dev.c:9443 [inline] netifsetmtuext+0x369/0x5c0 net/core/dev.c:9496 netifsetmtu+0xb0/0x160 net/core/dev.c:9520 devsetmtu+0xae/0x170 net/core/devapi.c:247 devifsioc+0xa31/0x18d0 net/core/devioctl.c:572 devioctl+0x223/0x10e0 net/core/devioctl.c:821 sockdoioctl+0x19d/0x280 net/socket.c:1204 sockioctl+0x42f/0x6a0 net/socket.c:1311 vfsioctl fs/ioctl.c:51 [inline] __dosysioctl fs/ioctl.c:906 [inline] __sesysioctl fs/ioctl.c:892 [inline] __x64sysioctl+0x190/0x200 fs/ioctl.c:892 dosyscallx64 arch/x86/entry/syscall64.c:63 [inline] dosyscall64+0xcd/0x260 arch/x86/entry/syscall64.c:94 entrySYSCALL64afterhwframe+0x77/0x7f

For historical and portability reasons, the netifrx() is usually run in the softirq or interrupt context, this commit therefore add localbhdisable/enable() protection in the usbnetresume_rx().