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| author | Dwight Engen <dwight.engen@oracle.com> | 2013-08-15 14:08:03 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-08 07:29:27 -0800 |
| commit | bdd0a8e5ace90cad14c1bf1bf49c3bfabb77f831 (patch) | |
| tree | e2abd7c0e71e115dfc11a7bf7849b2b729ca7c77 /fs/xfs | |
| parent | e8ef7efffbd51a4f256c5a3fe0c77f067db0c525 (diff) | |
| download | lwn-bdd0a8e5ace90cad14c1bf1bf49c3bfabb77f831.tar.gz lwn-bdd0a8e5ace90cad14c1bf1bf49c3bfabb77f831.zip | |
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/xfs')
| -rw-r--r-- | fs/xfs/xfs_ioctl.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 5e999680094a..ca01d830e989 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); |