From 84c39ec57d409e803a9bb6e4e85daf1243e0e80b Mon Sep 17 00:00:00 2001
From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date: Mon, 22 Jan 2024 19:34:21 +0100
Subject: [PATCH] exec: Fix error handling in begin_new_exec()
Git-commit: 84c39ec57d409e803a9bb6e4e85daf1243e0e80b
Patch-mainline: v6.8-rc2
References: git-fixes
If get_unused_fd_flags() fails, the error handling is incomplete because
bprm->cred is already set to NULL, and therefore free_bprm will not
unlock the cred_guard_mutex. Note there are two error conditions which
end up here, one before and one after bprm->cred is cleared.
Fixes: b8a61c9e7b4a ("exec: Generic execfd support")
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/AS8P193MB128517ADB5EFF29E04389EDAE4752@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
fs/exec.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/exec.c b/fs/exec.c
index 2037cc636036..39d773021fff 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1424,6 +1424,9 @@ int begin_new_exec(struct linux_binprm * bprm)
out_unlock:
up_write(&me->signal->exec_update_lock);
+ if (!bprm->cred)
+ mutex_unlock(&me->signal->cred_guard_mutex);
+
out:
return retval;
}
--
2.35.3