xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[patch 1/4] vfs: utimes: move owner check into inode_change_ok()

Browse Source 
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 <drepper@redhat.com>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Miklos Szeredi
2008-07-01 15:01:26 +02:00
committed by Al Viro
parent 88b387824f
commit 9767d74957
3 changed files with 22 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
fs/utimes.c
View File

@@ -101,7 +101,6 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags
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 *filename, struct timespec *times, int flags
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