The patch titled
r/o bind mounts: elevate write count for do_utimes()
has been added to the -mm tree. Its filename is
r-o-bind-mounts-elevate-write-count-for-do_utimes.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: r/o bind mounts: elevate write count for do_utimes()
From: Dave Hansen <haveblue@xxxxxxxxxx>
Now includes fix for oops seen by akpm.
"never let a libc developer write your kernel code" - hch
"nor, apparently, a kernel developer" - akpm
Acked-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Cc: Valdis Kletnieks <Valdis.Kletnieks@xxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Signed-off-by: Dave Hansen <haveblue@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/utimes.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff -puN fs/utimes.c~r-o-bind-mounts-elevate-write-count-for-do_utimes fs/utimes.c
--- a/fs/utimes.c~r-o-bind-mounts-elevate-write-count-for-do_utimes
+++ a/fs/utimes.c
@@ -2,6 +2,7 @@
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/linkage.h>
+#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/stat.h>
@@ -59,6 +60,7 @@ long do_utimes(int dfd, char __user *fil
struct inode *inode;
struct iattr newattrs;
struct file *f = NULL;
+ struct vfsmount *mnt;
error = -EINVAL;
if (times && (!nsec_valid(times[0].tv_nsec) ||
@@ -79,18 +81,20 @@ long do_utimes(int dfd, char __user *fil
if (!f)
goto out;
dentry = f->f_path.dentry;
+ mnt = f->f_path.mnt;
} else {
error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd);
if (error)
goto out;
dentry = nd.path.dentry;
+ mnt = nd.path.mnt;
}
inode = dentry->d_inode;
- error = -EROFS;
- if (IS_RDONLY(inode))
+ error = mnt_want_write(mnt);
+ if (error)
goto dput_and_out;
/* Don't worry, the checks are done in inode_change_ok() */
@@ -98,7 +102,7 @@ long do_utimes(int dfd, char __user *fil
if (times) {
error = -EPERM;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
- goto dput_and_out;
+ goto mnt_drop_write_and_out;
if (times[0].tv_nsec == UTIME_OMIT)
newattrs.ia_valid &= ~ATTR_ATIME;
@@ -118,22 +122,24 @@ long do_utimes(int dfd, char __user *fil
} else {
error = -EACCES;
if (IS_IMMUTABLE(inode))
- goto dput_and_out;
+ goto mnt_drop_write_and_out;
if (!is_owner_or_cap(inode)) {
if (f) {
if (!(f->f_mode & FMODE_WRITE))
- goto dput_and_out;
+ goto mnt_drop_write_and_out;
} else {
error = vfs_permission(&nd, MAY_WRITE);
if (error)
- goto dput_and_out;
+ goto mnt_drop_write_and_out;
}
}
}
mutex_lock(&inode->i_mutex);
error = notify_change(dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
+mnt_drop_write_and_out:
+ mnt_drop_write(mnt);
dput_and_out:
if (f)
fput(f);
_
Patches currently in -mm which might be from haveblue@xxxxxxxxxx are
enable-hotplug-memory-remove-for-ppc64.patch
reiserfs-eliminate-private-use-of-struct-file-in-xattr.patch
hppfs-pass-vfsmount-to-dentry_open.patch
check-for-null-vfsmount-in-dentry_open.patch
fix-up-new-filp-allocators.patch
do-namei_flags-calculation-inside-open_namei.patch
merge-open_namei-and-do_filp_open.patch
r-o-bind-mounts-stub-functions.patch
r-o-bind-mounts-create-helper-to-drop-file-write-access.patch
r-o-bind-mounts-drop-write-during-emergency-remount.patch
r-o-bind-mounts-elevate-write-count-for-vfs_rmdir.patch
r-o-bind-mounts-elevate-write-count-for-callers-of-vfs_mkdir.patch
r-o-bind-mounts-elevate-mnt_writers-for-unlink-callers.patch
r-o-bind-mounts-elevate-write-count-for-xattr_permission-callers.patch
r-o-bind-mounts-elevate-write-count-for-ncp_ioctl.patch
r-o-bind-mounts-write-counts-for-time-functions.patch
r-o-bind-mounts-elevate-write-count-for-do_utimes.patch
r-o-bind-mounts-write-count-for-file_update_time.patch
r-o-bind-mounts-write-counts-for-link-symlink.patch
r-o-bind-mounts-elevate-write-count-for-ioctls.patch
r-o-bind-mounts-elevate-write-count-for-opens.patch
r-o-bind-mounts-get-write-access-for-vfs_rename-callers.patch
r-o-bind-mounts-elevate-write-count-for-chmod-chown-callers.patch
r-o-bind-mounts-write-counts-for-truncate.patch
r-o-bind-mounts-elevate-count-for-xfs-timestamp-updates.patch
r-o-bind-mounts-make-access-use-new-r-o-helper.patch
r-o-bind-mounts-check-mnt-instead-of-superblock-directly.patch
r-o-bind-mounts-get-callers-of-vfs_mknod-create.patch
r-o-bind-mounts-track-numbers-of-writers-to-mounts.patch
r-o-bind-mounts-honor-mount-writer-counts-at-remount.patch
r-o-bind-mounts-debugging-for-missed-calls.patch
reiser4.patch
page-owner-tracking-leak-detector.patch
-
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