This is a note to let you know that I've just added the patch titled ext4: dont return EINVAL from GETFSUUID when reporting UUID length to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-dont-return-einval-from-getfsuuid-when-reporting-uuid-length.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b76abb5157468756163fe7e3431c9fe32cba57ca Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" <djwong@xxxxxxxxxx> Date: Thu, 10 Nov 2022 12:16:29 -0800 Subject: ext4: dont return EINVAL from GETFSUUID when reporting UUID length From: Darrick J. Wong <djwong@xxxxxxxxxx> commit b76abb5157468756163fe7e3431c9fe32cba57ca upstream. If userspace calls this ioctl with fsu_length (the length of the fsuuid.fsu_uuid array) set to zero, ext4 copies the desired uuid length out to userspace. The kernel call returned a result from a valid input, so the return value here should be zero, not EINVAL. While we're at it, fix the copy_to_user call to make it clear that we're only copying out fsu_len. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> Reviewed-by: Catherine Hoang <catherine.hoang@xxxxxxxxxx> Link: https://lore.kernel.org/r/166811138914.327006.9241306894437166566.stgit@magnolia Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/ioctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1154,9 +1154,10 @@ static int ext4_ioctl_getuuid(struct ext if (fsuuid.fsu_len == 0) { fsuuid.fsu_len = UUID_SIZE; - if (copy_to_user(ufsuuid, &fsuuid, sizeof(fsuuid.fsu_len))) + if (copy_to_user(&ufsuuid->fsu_len, &fsuuid.fsu_len, + sizeof(fsuuid.fsu_len))) return -EFAULT; - return -EINVAL; + return 0; } if (fsuuid.fsu_len < UUID_SIZE || fsuuid.fsu_flags != 0) Patches currently in stable-queue which might be from djwong@xxxxxxxxxx are queue-6.1/ext4-journal_path-mount-options-should-follow-links.patch queue-6.1/ext4-don-t-fail-getfsuuid-when-the-caller-provides-a-long-buffer.patch queue-6.1/ext4-dont-return-einval-from-getfsuuid-when-reporting-uuid-length.patch queue-6.1/ext4-fix-bad-checksum-after-online-resize.patch