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authorDwight Engen <dwight.engen@oracle.com>2013-08-15 14:08:03 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-08 07:29:27 -0800
commitbdd0a8e5ace90cad14c1bf1bf49c3bfabb77f831 (patch)
treee2abd7c0e71e115dfc11a7bf7849b2b729ca7c77 /fs
parente8ef7efffbd51a4f256c5a3fe0c77f067db0c525 (diff)
xfs: add capability check to free eofblocks ioctl
commit 8c567a7fab6e086a0284eee2db82348521e7120c upstream. Check for CAP_SYS_ADMIN since the caller can truncate preallocated blocks from files they do not own nor have write access to. A more fine grained access check was considered: require the caller to specify their own uid/gid and to use inode_permission to check for write, but this would not catch the case of an inode not reachable via path traversal from the callers mount namespace. Add check for read-only filesystem to free eofblocks ioctl. Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: Dwight Engen <dwight.engen@oracle.com> Signed-off-by: Ben Myers <bpm@sgi.com> Cc: Kees Cook <keescook@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/xfs/xfs_ioctl.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 5e999680094..ca01d830e98 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1612,6 +1612,12 @@ xfs_file_ioctl(
case XFS_IOC_FREE_EOFBLOCKS: {
struct xfs_eofblocks eofb;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (mp->m_flags & XFS_MOUNT_RDONLY)
+ return -XFS_ERROR(EROFS);
+
if (copy_from_user(&eofb, arg, sizeof(eofb)))
return -XFS_ERROR(EFAULT);