Commit ed40866e authored by Ilya Leoshkevich's avatar Ilya Leoshkevich Committed by Alexander Gordeev
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statfs: enforce statfs[64] structure initialization 



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: default avatarHeiko Carstens <hca@linux.ibm.com>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20230504144021.808932-2-iii@linux.ibm.com


Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent 2862a2fd

fs/statfs.c

+2 −2
Original line number Diff line number Diff line
@@ -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;