In the Linux kernel, the following vulnerability has been resolved:
scsi: bnx2fc: Make bnx2fcrecvframe() mp safe
Running tests with a debug kernel shows that bnx2fcrecvframe() is modifying the per_cpu lport stats counters in a non-mpsafe way. Just boot a debug kernel and run the bnx2fc driver with the hardware enabled.
[ 1391.699147] BUG: using smpprocessorid() in preemptible [00000000] code: bnx2fc_ [ 1391.699160] caller is bnx2fcrecvframe+0xbf9/0x1760 [bnx2fc] [ 1391.699174] CPU: 2 PID: 4355 Comm: bnx2fcl2threa Kdump: loaded Tainted: G B [ 1391.699180] Hardware name: HP ProLiant DL120 G7, BIOS J01 07/01/2013 [ 1391.699183] Call Trace: [ 1391.699188] dumpstacklvl+0x57/0x7d [ 1391.699198] checkpreemptiondisabled+0xc8/0xd0 [ 1391.699205] bnx2fcrecvframe+0xbf9/0x1760 [bnx2fc] [ 1391.699215] ? dorawspintrylock+0xb5/0x180 [ 1391.699221] ? bnx2fcnpivcreatevports.isra.0+0x4e0/0x4e0 [bnx2fc] [ 1391.699229] ? bnx2fcl2rcvthread+0xb7/0x3a0 [bnx2fc] [ 1391.699240] bnx2fcl2rcvthread+0x1af/0x3a0 [bnx2fc] [ 1391.699250] ? bnx2fculpinit+0xc0/0xc0 [bnx2fc] [ 1391.699258] kthread+0x364/0x420 [ 1391.699263] ? rawspinunlockirq+0x24/0x50 [ 1391.699268] ? setkthreadstruct+0x100/0x100 [ 1391.699273] retfromfork+0x22/0x30
Restore the old getcpu/putcpu code with some modifications to reduce the size of the critical section.