[1/2] statfs: Enforce statfs[64] structure intialization
Commit Message
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.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
fs/statfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
On Thu, 4 May 2023 16:40:20 +0200 Ilya Leoshkevich <iii@linux.ibm.com> wrote:
> 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.
>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
@@ -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;