From: Theodore Ts'o <tytso@mit.edu>
Date: Fri, 12 Aug 2022 04:08:16 +0000 (-0400)
Subject: libext2fs: avoid NULL dereference if the root file system isn't in /etc/mtab
X-Git-Tag: v1.47.0~26
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d5aba8e5d349272eb221e2aab3775bb942f89684;p=thirdparty%2Fe2fsprogs.git

libext2fs: avoid NULL dereference if the root file system isn't in /etc/mtab

Addresses-Coverity-Bug: 1497609
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
index c73273b84..f4fcdfd02 100644
--- a/lib/ext2fs/ismounted.c
+++ b/lib/ext2fs/ismounted.c
@@ -208,9 +208,10 @@ is_root:
 		(void) unlink(TEST_FILE);
 	}
 
-	if (!strcmp(mnt->mnt_type, "ext4") ||
-	    !strcmp(mnt->mnt_type, "ext3") ||
-	    !strcmp(mnt->mnt_type, "ext2"))
+	if (mnt && mnt->mnt_type &&
+	    (!strcmp(mnt->mnt_type, "ext4") ||
+	     !strcmp(mnt->mnt_type, "ext3") ||
+	     !strcmp(mnt->mnt_type, "ext2")))
 		*mount_flags |= EXT2_MF_EXTFS;
 	retval = 0;
 errout: