From: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> commit ed40866ec7d328b3dfb70db7e2011640a16202c3 upstream. s390's struct statfs and struct statfs64 contain padding, which field-by-field copying does not set. Initialize the respective structs with zeros before filling them and copying them to userspace, like it's already done for the compat versions of these structs. Found by KMSAN. [agordeev@xxxxxxxxxxxxx: fixed typo in patch description] Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v4.14+ Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230504144021.808932-2-iii@xxxxxxxxxxxxx Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/statfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/statfs.c +++ b/fs/statfs.c @@ -130,6 +130,7 @@ static int do_statfs_native(struct kstat if (sizeof(buf) == sizeof(*st)) memcpy(&buf, st, sizeof(*st)); else { + memset(&buf, 0, sizeof(buf)); if (sizeof buf.f_blocks == 4) { if ((st->f_blocks | st->f_bfree | st->f_bavail | st->f_bsize | st->f_frsize) & @@ -158,7 +159,6 @@ static int do_statfs_native(struct kstat buf.f_namelen = st->f_namelen; buf.f_frsize = st->f_frsize; buf.f_flags = st->f_flags; - memset(buf.f_spare, 0, sizeof(buf.f_spare)); } if (copy_to_user(p, &buf, sizeof(buf))) return -EFAULT; @@ -171,6 +171,7 @@ static int do_statfs64(struct kstatfs *s if (sizeof(buf) == sizeof(*st)) memcpy(&buf, st, sizeof(*st)); else { + memset(&buf, 0, sizeof(buf)); buf.f_type = st->f_type; buf.f_bsize = st->f_bsize; buf.f_blocks = st->f_blocks; @@ -182,7 +183,6 @@ static int do_statfs64(struct kstatfs *s buf.f_namelen = st->f_namelen; buf.f_frsize = st->f_frsize; buf.f_flags = st->f_flags; - memset(buf.f_spare, 0, sizeof(buf.f_spare)); } if (copy_to_user(p, &buf, sizeof(buf))) return -EFAULT;
