diff options
| author | Alex Elder <aelder@sgi.com> | 2011-03-01 17:50:00 +0000 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2011-04-30 16:53:36 +0200 |
| commit | c1227f9cd8a85dcf98efe03f884bf5da265fea5d (patch) | |
| tree | ca0e21de43dd911157e455f89c7a18974bd6377e | |
| parent | 4a82f99a10a5b1fdf56346b57884e7a08fc639b6 (diff) | |
xfs: zero proper structure size for geometry calls
commit af24ee9ea8d532e16883251a6684dfa1be8eec29 upstream.
Commit 493f3358cb289ccf716c5a14fa5bb52ab75943e5 added this call to
xfs_fs_geometry() in order to avoid passing kernel stack data back
to user space:
+ memset(geo, 0, sizeof(*geo));
Unfortunately, one of the callers of that function passes the
address of a smaller data type, cast to fit the type that
xfs_fs_geometry() requires. As a result, this can happen:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted
in: f87aca93
Pid: 262, comm: xfs_fsr Not tainted 2.6.38-rc6-493f3358cb2+ #1
Call Trace:
[<c12991ac>] ? panic+0x50/0x150
[<c102ed71>] ? __stack_chk_fail+0x10/0x18
[<f87aca93>] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs]
Fix this by fixing that one caller to pass the right type and then
copy out the subset it is interested in.
Note: This patch is an alternative to one originally proposed by
Eric Sandeen.
Reported-by: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>
Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Tested-by: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_ioctl.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c index 48799ba7e3e..eb5daf531eb 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl.c +++ b/fs/xfs/linux-2.6/xfs_ioctl.c @@ -762,14 +762,19 @@ xfs_ioc_fsgeometry_v1( xfs_mount_t *mp, void __user *arg) { - xfs_fsop_geom_v1_t fsgeo; + xfs_fsop_geom_t fsgeo; int error; - error = xfs_fs_geometry(mp, (xfs_fsop_geom_t *)&fsgeo, 3); + error = xfs_fs_geometry(mp, &fsgeo, 3); if (error) return -error; - if (copy_to_user(arg, &fsgeo, sizeof(fsgeo))) + /* + * Caller should have passed an argument of type + * xfs_fsop_geom_v1_t. This is a proper subset of the + * xfs_fsop_geom_t that xfs_fs_geometry() fills in. + */ + if (copy_to_user(arg, &fsgeo, sizeof(xfs_fsop_geom_v1_t))) return -XFS_ERROR(EFAULT); return 0; } |