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From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] objtool: check: Fix NULL pointer dereference
Date: Mon, 30 Mar 2020 19:20:40 -0500	[thread overview]
Message-ID: <20200331002040.GA11302@embeddedor> (raw)

In case func is null, there is a null pointer dereference at 2029:

2029                 WARN("%s uses BP as a scratch register",
2030                      func->name);

Fix this by null-checking func.

Addresses-Coverity-ID: 1492002 ("Dereference after null check")
Fixes: c705cecc8431 ("objtool: Track original function across branches")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 tools/objtool/check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e3bb76358148..182cc48fa892 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2025,7 +2025,7 @@ static int validate_return(struct symbol *func, struct instruction *insn, struct
 		return 1;
 	}
 
-	if (state->bp_scratch) {
+	if (func && state->bp_scratch) {
 		WARN("%s uses BP as a scratch register",
 		     func->name);
 		return 1;
-- 
2.26.0


             reply	other threads:[~2020-03-31  0:17 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-31  0:20 Gustavo A. R. Silva [this message]
2020-03-31 22:04 ` [PATCH] objtool: check: Fix NULL pointer dereference Josh Poimboeuf
2020-03-31 22:27   ` Gustavo A. R. Silva

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