Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758771AbYGANDt (ORCPT ); Tue, 1 Jul 2008 09:03:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756124AbYGANCI (ORCPT ); Tue, 1 Jul 2008 09:02:08 -0400 Received: from fxip-0047f.externet.hu ([88.209.222.127]:44044 "EHLO pomaz-ex.szeredi.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755140AbYGANCD (ORCPT ); Tue, 1 Jul 2008 09:02:03 -0400 Message-Id: <20080701130150.978939061@szeredi.hu> References: <20080701130125.529844715@szeredi.hu> User-Agent: quilt/0.45-1 Date: Tue, 01 Jul 2008 15:01:26 +0200 From: Miklos Szeredi To: viro@ZenIV.linux.org.uk Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, Ulrich Drepper , Michael Kerrisk Subject: [patch 1/4] vfs: utimes: move owner check into inode_change_ok() Content-Disposition: inline; filename=vfs-utimes-move-owner-check-into-inode_change_ok.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4656 Lines: 127 From: Miklos Szeredi Add a new ia_valid flag: ATTR_TIMES_SET, to handle the UTIMES_OMIT/UTIMES_NOW and UTIMES_NOW/UTIMES_OMIT cases. In these cases neither ATTR_MTIME_SET nor ATTR_ATIME_SET is in the flags, yet the POSIX draft specifies that permission checking is performed the same way as if one or both of the times was explicitly set to a timestamp. See the path "vfs: utimensat(): fix error checking for {UTIME_NOW,UTIME_OMIT} case" by Michael Kerrisk for the patch introducing this behavior. This is a cleanup, as well as allowing filesystems (NFS/fuse/...) to perform their own permission checking instead of the default. CC: Ulrich Drepper CC: Michael Kerrisk Signed-off-by: Miklos Szeredi --- fs/attr.c | 2 +- fs/utimes.c | 17 ++++------------- include/linux/fs.h | 33 +++++++++++++++++---------------- 3 files changed, 22 insertions(+), 30 deletions(-) Index: linux-2.6/fs/attr.c =================================================================== --- linux-2.6.orig/fs/attr.c 2008-06-27 22:09:08.000000000 +0200 +++ linux-2.6/fs/attr.c 2008-07-01 13:52:20.000000000 +0200 @@ -51,7 +51,7 @@ int inode_change_ok(struct inode *inode, } /* Check for setting the inode time. */ - if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) { + if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) { if (!is_owner_or_cap(inode)) goto error; } Index: linux-2.6/fs/utimes.c =================================================================== --- linux-2.6.orig/fs/utimes.c 2008-07-01 08:10:12.000000000 +0200 +++ linux-2.6/fs/utimes.c 2008-07-01 13:52:20.000000000 +0200 @@ -101,7 +101,6 @@ long do_utimes(int dfd, char __user *fil times[1].tv_nsec == UTIME_NOW) times = NULL; - /* In most cases, the checks are done in inode_change_ok() */ newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; if (times) { error = -EPERM; @@ -123,21 +122,13 @@ long do_utimes(int dfd, char __user *fil newattrs.ia_mtime.tv_nsec = times[1].tv_nsec; newattrs.ia_valid |= ATTR_MTIME_SET; } - /* - * For the UTIME_OMIT/UTIME_NOW and UTIME_NOW/UTIME_OMIT - * cases, we need to make an extra check that is not done by - * inode_change_ok(). + * Tell inode_change_ok(), that this is an explicit time + * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET + * were used. */ - if (((times[0].tv_nsec == UTIME_NOW && - times[1].tv_nsec == UTIME_OMIT) - || - (times[0].tv_nsec == UTIME_OMIT && - times[1].tv_nsec == UTIME_NOW)) - && !is_owner_or_cap(inode)) - goto mnt_drop_write_and_out; + newattrs.ia_valid |= ATTR_TIMES_SET; } else { - /* * If times is NULL (or both times are UTIME_NOW), * then we need to check permissions, because Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2008-07-01 13:52:19.000000000 +0200 +++ linux-2.6/include/linux/fs.h 2008-07-01 13:52:20.000000000 +0200 @@ -317,22 +317,23 @@ typedef void (dio_iodone_t)(struct kiocb * Attribute flags. These should be or-ed together to figure out what * has been changed! */ -#define ATTR_MODE 1 -#define ATTR_UID 2 -#define ATTR_GID 4 -#define ATTR_SIZE 8 -#define ATTR_ATIME 16 -#define ATTR_MTIME 32 -#define ATTR_CTIME 64 -#define ATTR_ATIME_SET 128 -#define ATTR_MTIME_SET 256 -#define ATTR_FORCE 512 /* Not a change, but a change it */ -#define ATTR_ATTR_FLAG 1024 -#define ATTR_KILL_SUID 2048 -#define ATTR_KILL_SGID 4096 -#define ATTR_FILE 8192 -#define ATTR_KILL_PRIV 16384 -#define ATTR_OPEN 32768 /* Truncating from open(O_TRUNC) */ +#define ATTR_MODE (1 << 0) +#define ATTR_UID (1 << 1) +#define ATTR_GID (1 << 2) +#define ATTR_SIZE (1 << 3) +#define ATTR_ATIME (1 << 4) +#define ATTR_MTIME (1 << 5) +#define ATTR_CTIME (1 << 6) +#define ATTR_ATIME_SET (1 << 7) +#define ATTR_MTIME_SET (1 << 8) +#define ATTR_FORCE (1 << 9) /* Not a change, but a change it */ +#define ATTR_ATTR_FLAG (1 << 10) +#define ATTR_KILL_SUID (1 << 11) +#define ATTR_KILL_SGID (1 << 12) +#define ATTR_FILE (1 << 13) +#define ATTR_KILL_PRIV (1 << 14) +#define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */ +#define ATTR_TIMES_SET (1 << 16) /* * This is the Inode Attributes structure, used for notify_change(). 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