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| author | Darrick J. Wong <djwong@kernel.org> | 2022-11-10 12:16:34 -0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2022-12-08 21:49:24 -0500 |
| commit | a7e9d977e031fceefe1e7cd69ebd7202d5758b56 (patch) | |
| tree | 0bb1c6961ea66042b751bc4b4b765edf6779825e | |
| parent | b76abb5157468756163fe7e3431c9fe32cba57ca (diff) | |
| download | linux-stable-a7e9d977e031fceefe1e7cd69ebd7202d5758b56.tar.gz linux-stable-a7e9d977e031fceefe1e7cd69ebd7202d5758b56.tar.bz2 linux-stable-a7e9d977e031fceefe1e7cd69ebd7202d5758b56.zip | |
ext4: don't fail GETFSUUID when the caller provides a long buffer
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
| -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 beedaebab21c..202953b5db49 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1160,14 +1160,16 @@ static int ext4_ioctl_getuuid(struct ext4_sb_info *sbi, return 0; } - 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; } |