From: Eric Biggers <ebiggers@google.com>
Date: Fri, 13 May 2022 23:16:01 +0000 (-0700)
Subject: ext4: fix memory leak in parse_apply_sb_mount_options()
X-Git-Tag: v5.18.3~141
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f92ded66e9d0aa20b883a2a5183973abc8f41815;p=thirdparty%2Fkernel%2Fstable.git

ext4: fix memory leak in parse_apply_sb_mount_options()

commit c069db76ed7b681c69159f44be96d2137e9ca989 upstream.

If processing the on-disk mount options fails after any memory was
allocated in the ext4_fs_context, e.g. s_qf_names, then this memory is
leaked.  Fix this by calling ext4_fc_free() instead of kfree() directly.

Reproducer:

    mkfs.ext4 -F /dev/vdc
    tune2fs /dev/vdc -E mount_opts=usrjquota=file
    echo clear > /sys/kernel/debug/kmemleak
    mount /dev/vdc /vdc
    echo scan > /sys/kernel/debug/kmemleak
    sleep 5
    echo scan > /sys/kernel/debug/kmemleak
    cat /sys/kernel/debug/kmemleak

Fixes: 7edfd85b1ffd ("ext4: Completely separate options parsing and sb setup")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Tested-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220513231605.175121-2-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ab0ce9ac8d455..18695f7b525eb 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2626,8 +2626,10 @@ parse_failed:
 	ret = ext4_apply_options(fc, sb);
 
 out_free:
-	kfree(s_ctx);
-	kfree(fc);
+	if (fc) {
+		ext4_fc_free(fc);
+		kfree(fc);
+	}
 	kfree(s_mount_opts);
 	return ret;
 }