objtool: Fix SEGFAULT

[ Upstream commit efb11fdb3e1a9f694fa12b70b21e69e55ec59c36 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index edac5aa..308c880 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -197,7 +197,7 @@ 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) {