statfs: enforce statfs[64] structure initialization

commit ed40866ec7 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@linux.ibm.com: fixed typo in patch description]
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20230504144021.808932-2-iii@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ilya Leoshkevich 2023-05-04 16:40:20 +02:00 committed by Greg Kroah-Hartman
parent 865be1cff2
commit 51d90382d2

View File

@ -130,6 +130,7 @@ static int do_statfs_native(struct kstatfs *st, struct statfs __user *p)
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 kstatfs *st, struct statfs __user *p)
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 *st, struct statfs64 __user *p)
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 *st, struct statfs64 __user *p)
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;