diff options
Diffstat (limited to 'fs/utimes.c')
| -rw-r--r-- | fs/utimes.c | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/fs/utimes.c b/fs/utimes.c index b18da9c0b97f..af059d5cb485 100644 --- a/fs/utimes.c +++ b/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> @@ -39,9 +40,14 @@ asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times) #endif +static bool nsec_special(long nsec) +{ + return nsec == UTIME_OMIT || nsec == UTIME_NOW; +} + static bool nsec_valid(long nsec) { - if (nsec == UTIME_OMIT || nsec == UTIME_NOW) + if (nsec_special(nsec)) return true; return nsec >= 0 && nsec <= 999999999; @@ -59,6 +65,7 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags 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 +86,20 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags 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 +107,7 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags 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; @@ -115,25 +124,35 @@ 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; } - } else { + } + + /* + * If times is NULL or both times are either UTIME_OMIT or + * UTIME_NOW, then need to check permissions, because + * inode_change_ok() won't do it. + */ + if (!times || (nsec_special(times[0].tv_nsec) && + nsec_special(times[1].tv_nsec))) { 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); |