diff options
| author | Darrick J. Wong | 2022-11-10 12:16:34 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-01-07 11:12:01 +0100 |
| commit | b753b0be45ae3eb4a37a6a9efb69a3ba486b81ea (patch) | |
| tree | 37938bee3898d3963f19d76f16134bee08eeb23a /fs/ext4/ioctl.c | |
| parent | 13271fbbe85d73a7c47058f56a52f2a7f00d6e39 (diff) | |
ext4: don't fail GETFSUUID when the caller provides a long buffer
commit a7e9d977e031fceefe1e7cd69ebd7202d5758b56 upstream.
If userspace provides a longer UUID buffer than is required, we
shouldn't fail the call with EINVAL -- rather, we can fill the caller's
buffer with the bytes we /can/ fill, and update the length field to
reflect what we copied. This doesn't break the UAPI since we're
enabling a case that currently fails, and so far Ted hasn't released a
version of e2fsprogs that uses the new ext4 ioctl.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Catherine Hoang <catherine.hoang@oracle.com>
Link: https://lore.kernel.org/r/166811139478.327006.13879198441587445544.stgit@magnolia
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4/ioctl.c')
| -rw-r--r-- | fs/ext4/ioctl.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index e5f60057db5b..5a12f87df45e 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1159,14 +1159,16 @@ static int ext4_ioctl_getuuid(struct ext4_sb_info *sbi, return -EINVAL; } - if (fsuuid.fsu_len != UUID_SIZE || fsuuid.fsu_flags != 0) + if (fsuuid.fsu_len < UUID_SIZE || fsuuid.fsu_flags != 0) return -EINVAL; lock_buffer(sbi->s_sbh); memcpy(uuid, sbi->s_es->s_uuid, UUID_SIZE); unlock_buffer(sbi->s_sbh); - if (copy_to_user(&ufsuuid->fsu_uuid[0], uuid, UUID_SIZE)) + fsuuid.fsu_len = UUID_SIZE; + if (copy_to_user(ufsuuid, &fsuuid, sizeof(fsuuid)) || + copy_to_user(&ufsuuid->fsu_uuid[0], uuid, UUID_SIZE)) return -EFAULT; return 0; } |