objtool: Fix SEGFAULT

find_insn() will return NULL in case of failure. Check insn in order
to avoid a kernel Oops for NULL pointer dereference.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-9-sv@linux.ibm.com

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 43ec14c29a60c1d63243bf2d0bfeee6552130bae..8427af808221bce50c8d7b85a811408057e81534 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -207,7 +207,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
                return false;
 
        insn = find_insn(file, func->sec, func->offset);
-       if (!insn->func)
+       if (!insn || !insn->func)
                return false;
 
        func_for_each_insn(file, func, insn) {