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| author | Theodore Ts'o <tytso@mit.edu> | 2025-10-21 13:41:57 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-29 14:01:24 +0100 |
| commit | b2bac84fde28fb6a88817b8b761abda17a1d300b (patch) | |
| tree | c80b563415333ff867191ecf995cf84beb3c5eb2 | |
| parent | a7f0743d402fba6fe8320a1f8dc2404f09238a9e (diff) | |
| download | linux-b2bac84fde28fb6a88817b8b761abda17a1d300b.tar.gz linux-b2bac84fde28fb6a88817b8b761abda17a1d300b.tar.bz2 linux-b2bac84fde28fb6a88817b8b761abda17a1d300b.zip | |
ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
[ Upstream commit 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 ]
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>
[ applied to ext4_fill_super() instead of parse_apply_sb_mount_options() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/ext4/super.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 3957ff246bff..453e746ba361 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4282,18 +4282,16 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } if (sbi->s_es->s_mount_opts[0]) { - char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts, - sizeof(sbi->s_es->s_mount_opts), - GFP_KERNEL); - if (!s_mount_opts) - goto failed_mount; + char s_mount_opts[65]; + + strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts, + sizeof(s_mount_opts)); if (!parse_options(s_mount_opts, sb, &journal_devnum, &journal_ioprio, 0)) { ext4_msg(sb, KERN_WARNING, "failed to parse options in superblock: %s", s_mount_opts); } - kfree(s_mount_opts); } sbi->s_def_mount_opt = sbi->s_mount_opt; if (!parse_options((char *) data, sb, &journal_devnum, |