Calling bpf_get_smp_processor_id() in a kernel with CONFIG_SMP disabled
can trigger the following bug, as pcpu_hot 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 preventing the inlining of bpf_get_smp_processor_id() when
CONFIG_SMP disabled.
Fixes: 1ae6921009e5 ("bpf: inline bpf_get_smp_processor_id() helper")
Signed-off-by: Andrea Righi <arighi@xxxxxxxxxx>
---
kernel/bpf/verifier.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f7f892a52a37..d85413f1a784 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -21272,7 +21272,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
goto next_insn;
}
-#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
+#if defined(CONFIG_SMP) && defined(CONFIG_X86_64) && !defined(CONFIG_UML)
/* Implement bpf_get_smp_processor_id() inline. */
if (insn->imm == BPF_FUNC_get_smp_processor_id &&
verifier_inlines_helper_call(env, insn->imm)) {
--
2.47.1
