In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix bpfgetsmpprocessorid() on !CONFIG_SMP
On x86-64 calling bpfgetsmpprocessorid() in a kernel with CONFIGSMP disabled can trigger the following bug, as pcpuhot is unavailable:
[ 8.471774] BUG: unable to handle page fault for address: 00000000936a290c [ 8.471849] #PF: supervisor read access in kernel mode [ 8.471881] #PF: error_code(0x0000) - not-present page
Fix by inlining a return 0 in the !CONFIG_SMP case.