diff mbox series

[1/2] statfs: Enforce statfs[64] structure intialization

Message ID 20230504144021.808932-2-iii@linux.ibm.com
State New
Headers
Series statfs: Enforce statfs[64] structure intialization |

Commit Message

Ilya Leoshkevich May 4, 2023, 2:40 p.m. UTC 
  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

Andrew Morton May 12, 2023, 3:45 a.m. UTC | #1 
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>
diff mbox series

Patch

diff --git a/fs/statfs.c b/fs/statfs.c
index 0ba34c135593..96d1c3edf289 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -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;