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[PATCH] fix MAY_CHDIR/MAY_ACCESS/LOOKUP_ACCESS mess

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* MAY_CHDIR is redundant - it's an equivalent of MAY_ACCESS
* MAY_ACCESS on fuse should affect only the last step of pathname resolution
* fchdir() and chroot() should pass MAY_ACCESS, for the same reason why
  chdir() needs that.
* now that we pass MAY_ACCESS explicitly in all cases, LOOKUP_ACCESS can be
  removed; it has no business being in nameidata.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2008-07-17 09:19:08 -04:00
parent 7f2da1e7d0
commit a110343f0d
5 changed files with 7 additions and 11 deletions
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2
fs/fuse/dir.c
View File

@ -962,7 +962,7 @@ static int fuse_permission(struct inode *inode, int mask)
exist. So if permissions are revoked this won't be
noticed immediately, only after the attribute
timeout has expired */
} else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
} else if (mask & MAY_ACCESS) {
err = fuse_access(inode, mask);
} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
if (!(inode->i_mode & S_IXUGO)) {

2
fs/namei.c
View File

@ -265,8 +265,6 @@ int permission(struct inode *inode, int mask, struct nameidata *nd)
if (inode->i_op && inode->i_op->permission) {
int extra = 0;
if (nd) {
if (nd->flags & LOOKUP_ACCESS)
extra |= MAY_ACCESS;
if (nd->flags & LOOKUP_OPEN)
extra |= MAY_OPEN;
}

10
fs/open.c
View File

@ -457,11 +457,11 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
old_cap = cap_set_effective(current->cap_permitted);
}
res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
if (res)
goto out;
res = vfs_permission(&nd, mode);
res = vfs_permission(&nd, mode | MAY_ACCESS);
/* SuS v2 requires we report a read only fs too */
if(res || !(mode & S_IWOTH) ||
special_file(nd.path.dentry->d_inode->i_mode))
@ -505,7 +505,7 @@ asmlinkage long sys_chdir(const char __user * filename)
if (error)
goto out;
error = vfs_permission(&nd, MAY_EXEC | MAY_CHDIR);
error = vfs_permission(&nd, MAY_EXEC | MAY_ACCESS);
if (error)
goto dput_and_out;
@ -534,7 +534,7 @@ asmlinkage long sys_fchdir(unsigned int fd)
if (!S_ISDIR(inode->i_mode))
goto out_putf;
error = file_permission(file, MAY_EXEC);
error = file_permission(file, MAY_EXEC | MAY_ACCESS);
if (!error)
set_fs_pwd(current->fs, &file->f_path);
out_putf:
@ -552,7 +552,7 @@ asmlinkage long sys_chroot(const char __user * filename)
if (error)
goto out;
error = vfs_permission(&nd, MAY_EXEC);
error = vfs_permission(&nd, MAY_EXEC | MAY_ACCESS);
if (error)
goto dput_and_out;

3
include/linux/fs.h
View File

@ -61,8 +61,7 @@ extern int dir_notify_enable;
#define MAY_READ 4
#define MAY_APPEND 8
#define MAY_ACCESS 16
#define MAY_CHDIR 32
#define MAY_OPEN 64
#define MAY_OPEN 32
#define FMODE_READ 1
#define FMODE_WRITE 2

1
include/linux/namei.h
View File

@ -53,7 +53,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
*/
#define LOOKUP_OPEN (0x0100)
#define LOOKUP_CREATE (0x0200)
#define LOOKUP_ACCESS (0x0400)
extern int __user_walk(const char __user *, unsigned, struct nameidata *);
extern int __user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *);