CVE-2023-53281

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

drivers: staging: rtl8723bs: Fix locking in rtwjointimeouthandler()

Commit 041879b12ddb ("drivers: staging: rtl8192bs: Fix deadlock in rtwjoinbsseventprehandle()") besides fixing the deadlock also modified rtwjointimeouthandler() to use spin[un]lockirq() instead of spin[un]lock_bh().

rtwjointimeouthandler() calls rtwdojoin() which takes pmlmepriv->scannedqueue.lock using spin[un]lockbh(). This spinunlock_bh() call re-enables softirqs which triggers an oops in kernel/softirq.c: __localbhenableip() when it calls lockdepassertirqsenabled():

[ 244.506087] WARNING: CPU: 2 PID: 0 at kernel/softirq.c:376 __localbhenableip+0xa6/0x100 ... [ 244.509022] Call Trace: [ 244.509048] <IRQ> [ 244.509100] rtwjointimeouthandler+0x134/0x170 [r8723bs] [ 244.509468] ? pfxrtwjointimeouthandler+0x10/0x10 [r8723bs] [ 244.509772] ? pfxrtw_jointimeouthandler+0x10/0x10 [r8723bs] [ 244.510076] calltimerfn+0x95/0x2a0 [ 244.510200] _runtimers.part.0+0x1da/0x2d0

This oops is causd by the switch to spin_[un]lockirq() which disables the IRQs for the entire duration of rtwjointimeout_handler().

Disabling the IRQs is not necessary since all code taking this lock runs from either user contexts or from softirqs, switch back to spin_[un]lock_bh() to fix this.