->permission() sanitizing: MAY_NOT_BLOCK

Duplicate the flags argument into mask bitmap.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-06-20 18:59:02 -04:00
parent 178ea73521
commit 1fc0f78ca9
3 changed files with 7 additions and 3 deletions

View file

@ -318,13 +318,16 @@ static inline int exec_permission(struct inode *inode, unsigned int flags)
{
int ret;
struct user_namespace *ns = inode_userns(inode);
int mask = MAY_EXEC;
if (flags & IPERM_FLAG_RCU)
mask |= MAY_NOT_BLOCK;
if (inode->i_op->permission) {
ret = inode->i_op->permission(inode, MAY_EXEC, flags);
ret = inode->i_op->permission(inode, mask, flags);
if (likely(!ret))
goto ok;
} else {
ret = acl_permission_check(inode, MAY_EXEC, flags);
ret = acl_permission_check(inode, mask, flags);
if (likely(!ret))
goto ok;
if (ret != -EACCES)

View file

@ -316,7 +316,7 @@ static int proc_sys_permission(struct inode *inode, int mask,unsigned int flags)
if (!table) /* global root - r-xr-xr-x */
error = mask & MAY_WRITE ? -EACCES : 0;
else /* Use the permissions on the sysctl table entry */
error = sysctl_perm(head->root, table, mask);
error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK);
sysctl_head_finish(head);
return error;

View file

@ -63,6 +63,7 @@ struct inodes_stat_t {
#define MAY_ACCESS 16
#define MAY_OPEN 32
#define MAY_CHDIR 64
#define MAY_NOT_BLOCK 128 /* called from RCU mode, don't block */
/*
* flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond