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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Gaosheng Cui <cuigaosheng1@huawei.com>,
        Jan Kara <jack@suse.cz>, Paul Moore <paul@paul-moore.com>
Subject: [PATCH 5.4 01/77] audit: fix potential double free on error path from fsnotify_add_inode_mark
Date:   Fri,  2 Sep 2022 14:18:10 +0200
Message-Id: <20220902121403.635952136@linuxfoundation.org>
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From: Gaosheng Cui <cuigaosheng1@huawei.com>

commit ad982c3be4e60c7d39c03f782733503cbd88fd2a upstream.

Audit_alloc_mark() assign pathname to audit_mark->path, on error path
from fsnotify_add_inode_mark(), fsnotify_put_mark will free memory
of audit_mark->path, but the caller of audit_alloc_mark will free
the pathname again, so there will be double free problem.

Fix this by resetting audit_mark->path to NULL pointer on error path
from fsnotify_add_inode_mark().

Cc: stable@vger.kernel.org
Fixes: 7b1293234084d ("fsnotify: Add group pointer in fsnotify_init_mark()")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 kernel/audit_fsnotify.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -102,6 +102,7 @@ struct audit_fsnotify_mark *audit_alloc_
 
 	ret = fsnotify_add_inode_mark(&audit_mark->mark, inode, true);
 	if (ret < 0) {
+		audit_mark->path = NULL;
 		fsnotify_put_mark(&audit_mark->mark);
 		audit_mark = ERR_PTR(ret);
 	}