CVE-2025-37993

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

can: mcan: mcanclassallocate_dev(): initialize spin lock on device probe

The spin lock txhandlingspinlock in struct mcanclassdev is not being initialized. This leads the following spinlock bad magic complaint from the kernel, eg. when trying to send CAN frames with cansend from can-utils:

| BUG: spinlock bad magic on CPU#0, cansend/95 | lock: 0xff60000002ec1010, .magic: 00000000, .owner: <none>/-1, .ownercpu: 0 | CPU: 0 UID: 0 PID: 95 Comm: cansend Not tainted 6.15.0-rc3-00032-ga79be02bba5c #5 NONE | Hardware name: MachineWare SIM-V (DT) | Call Trace: | [<ffffffff800133e0>] dumpbacktrace+0x1c/0x24 | [<ffffffff800022f2>] showstack+0x28/0x34 | [<ffffffff8000de3e>] dumpstacklvl+0x4a/0x68 | [<ffffffff8000de70>] dumpstack+0x14/0x1c | [<ffffffff80003134>] spindump+0x62/0x6e | [<ffffffff800883ba>] dorawspinlock+0xd0/0x142 | [<ffffffff807a6fcc>] rawspinlockirqsave+0x20/0x2c | [<ffffffff80536dba>] mcanstartxmit+0x90/0x34a | [<ffffffff806148b0>] devhardstartxmit+0xa6/0xee | [<ffffffff8065b730>] schdirectxmit+0x114/0x292 | [<ffffffff80614e2a>] _devqueuexmit+0x3b0/0xaa8 | [<ffffffff8073b8fa>] cansend+0xc6/0x242 | [<ffffffff8073d1c0>] rawsendmsg+0x1a8/0x36c | [<ffffffff805ebf06>] sockwriteiter+0x9a/0xee | [<ffffffff801d06ea>] vfswrite+0x184/0x3a6 | [<ffffffff801d0a88>] ksyswrite+0xa0/0xc0 | [<ffffffff801d0abc>] _riscvsyswrite+0x14/0x1c | [<ffffffff8079ebf8>] dotrapecallu+0x168/0x212 | [<ffffffff807a830a>] handleexception+0x146/0x152

Initializing the spin lock in mcanclassallocatedev solves that problem.