diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2025-09-16 23:22:47 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2025-09-26 08:36:08 -0400 |
| commit | 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 (patch) | |
| tree | b53034d2aeb4a70fd127c37475b4efdb177ef833 | |
| parent | 12e803c8827d049ae8f2c743ef66ab87ae898375 (diff) | |
ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
Unlike other strings in the ext4 superblock, we rely on tune2fs to
make sure s_mount_opts is NUL terminated. Harden
parse_apply_sb_mount_options() by treating s_mount_opts as a potential
__nonstring.
Cc: stable@vger.kernel.org
Fixes: 8b67f04ab9de ("ext4: Add mount options in superblock")
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Message-ID: <20250916-tune2fs-v2-1-d594dc7486f0@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/super.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d26e5c0731e5..488f4c281a3f 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2469,7 +2469,7 @@ static int parse_apply_sb_mount_options(struct super_block *sb, struct ext4_fs_context *m_ctx) { struct ext4_sb_info *sbi = EXT4_SB(sb); - char *s_mount_opts = NULL; + char s_mount_opts[65]; struct ext4_fs_context *s_ctx = NULL; struct fs_context *fc = NULL; int ret = -ENOMEM; @@ -2477,15 +2477,11 @@ static int parse_apply_sb_mount_options(struct super_block *sb, if (!sbi->s_es->s_mount_opts[0]) return 0; - s_mount_opts = kstrndup(sbi->s_es->s_mount_opts, - sizeof(sbi->s_es->s_mount_opts), - GFP_KERNEL); - if (!s_mount_opts) - return ret; + strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts); fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL); if (!fc) - goto out_free; + return -ENOMEM; s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL); if (!s_ctx) @@ -2517,11 +2513,8 @@ parse_failed: ret = 0; out_free: - if (fc) { - ext4_fc_free(fc); - kfree(fc); - } - kfree(s_mount_opts); + ext4_fc_free(fc); + kfree(fc); return ret; } |