linux-kernel - [PATCH next] binfmt_elf: Fix potential Oops in load_elf

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <5952b626-ef08-4293-8a73-f1496af4e987@stanley.mountain>
Date: Wed, 11 Dec 2024 12:21:39 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Amir Goldstein <amir73il@...il.com>
Cc: Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
	Kees Cook <kees@...nel.org>, Eric Biederman <ebiederm@...ssion.com>,
	linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: [PATCH next] binfmt_elf: Fix potential Oops in load_elf_binary()

This function call was changed from allow_write_access() which has a NULL
check to exe_file_allow_write_access() which doesn't.  Check for NULL
before calling it.

Fixes: 871387b27c20 ("fs: don't block write during exec on pre-content watched files")
Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>
---
 fs/binfmt_elf.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 8054f44d39cf..db9cb4c20125 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1354,9 +1354,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
 	kfree(interp_elf_ex);
 	kfree(interp_elf_phdata);
 out_free_file:
-	exe_file_allow_write_access(interpreter);
-	if (interpreter)
+	if (interpreter) {
+		exe_file_allow_write_access(interpreter);
 		fput(interpreter);
+	}
 out_free_ph:
 	kfree(elf_phdata);
 	goto out;
-- 
2.45.2