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authorDarrick J. Wong <darrick.wong@oracle.com>2017-04-04 01:17:57 +0300
committerDarrick J. Wong <darrick.wong@oracle.com>2017-04-04 01:18:16 +0300
commitbe6324c00c4d1e0e665f03ed1fc18863a88da119 (patch)
tree276214b108e95e5bec99e26e7087c384b8f590d2 /fs/xfs/xfs_ioctl.c
parent422e5b53ed83dd71c1eac276c6ec7f7c6e81ce8d (diff)
downloadlinux-be6324c00c4d1e0e665f03ed1fc18863a88da119.tar.xz
xfs: fix over-copying of getbmap parameters from userspace
In xfs_ioc_getbmap, we should only copy the fields of struct getbmap from userspace, or else we end up copying random stack contents into the kernel. struct getbmap is a strict subset of getbmapx, so a partial structure copy should work fine. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/xfs_ioctl.c')
-rw-r--r--fs/xfs/xfs_ioctl.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 2fd7fdf5438f..6d30b06e79bc 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1543,10 +1543,11 @@ xfs_ioc_getbmap(
unsigned int cmd,
void __user *arg)
{
- struct getbmapx bmx;
+ struct getbmapx bmx = { 0 };
int error;
- if (copy_from_user(&bmx, arg, sizeof(struct getbmapx)))
+ /* struct getbmap is a strict subset of struct getbmapx. */
+ if (copy_from_user(&bmx, arg, offsetof(struct getbmapx, bmv_iflags)))
return -EFAULT;
if (bmx.bmv_count < 2)