diff options
| -rw-r--r-- | fs/namei.c | 5 | ||||
| -rw-r--r-- | include/linux/security.h | 12 | ||||
| -rw-r--r-- | security/capability.c | 3 | ||||
| -rw-r--r-- | security/security.c | 7 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 16 |
5 files changed, 32 insertions, 11 deletions
diff --git a/fs/namei.c b/fs/namei.c index 33b655de0ec0..0fa7af23cff6 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -881,8 +881,9 @@ const char *get_link(struct nameidata *nd) touch_atime(&last->link); - error = security_inode_follow_link(dentry); - if (error) + error = security_inode_follow_link(dentry, inode, + nd->flags & LOOKUP_RCU); + if (unlikely(error)) return ERR_PTR(error); nd->last_type = LAST_BIND; diff --git a/include/linux/security.h b/include/linux/security.h index 62a66202ecf1..52febde52479 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -476,6 +476,8 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @inode_follow_link: * Check permission to follow a symbolic link when looking up a pathname. * @dentry contains the dentry structure for the link. + * @inode contains the inode, which itself is not stable in RCU-walk + * @rcu indicates whether we are in RCU-walk mode. * Return 0 if permission is granted. * @inode_permission: * Check permission before accessing an inode. This hook is called by the @@ -1551,7 +1553,8 @@ struct security_operations { int (*inode_rename) (struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry); int (*inode_readlink) (struct dentry *dentry); - int (*inode_follow_link) (struct dentry *dentry); + int (*inode_follow_link) (struct dentry *dentry, struct inode *inode, + bool rcu); int (*inode_permission) (struct inode *inode, int mask); int (*inode_setattr) (struct dentry *dentry, struct iattr *attr); int (*inode_getattr) (const struct path *path); @@ -1837,7 +1840,8 @@ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags); int security_inode_readlink(struct dentry *dentry); -int security_inode_follow_link(struct dentry *dentry); +int security_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu); int security_inode_permission(struct inode *inode, int mask); int security_inode_setattr(struct dentry *dentry, struct iattr *attr); int security_inode_getattr(const struct path *path); @@ -2239,7 +2243,9 @@ static inline int security_inode_readlink(struct dentry *dentry) return 0; } -static inline int security_inode_follow_link(struct dentry *dentry) +static inline int security_inode_follow_link(struct dentry *dentry, + struct inode *inode, + bool rcu) { return 0; } diff --git a/security/capability.c b/security/capability.c index fae99db180ca..7d3f38fe02ba 100644 --- a/security/capability.c +++ b/security/capability.c @@ -209,7 +209,8 @@ static int cap_inode_readlink(struct dentry *dentry) return 0; } -static int cap_inode_follow_link(struct dentry *dentry) +static int cap_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu) { return 0; } diff --git a/security/security.c b/security/security.c index d7c30b03e144..04c8feca081a 100644 --- a/security/security.c +++ b/security/security.c @@ -581,11 +581,12 @@ int security_inode_readlink(struct dentry *dentry) return security_ops->inode_readlink(dentry); } -int security_inode_follow_link(struct dentry *dentry) +int security_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu) { - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + if (unlikely(IS_PRIVATE(inode))) return 0; - return security_ops->inode_follow_link(dentry); + return security_ops->inode_follow_link(dentry, inode, rcu); } int security_inode_permission(struct inode *inode, int mask) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index d56a82967d5e..ffa5a642629a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2861,11 +2861,23 @@ static int selinux_inode_readlink(struct dentry *dentry) return dentry_has_perm(cred, dentry, FILE__READ); } -static int selinux_inode_follow_link(struct dentry *dentry) +static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu) { const struct cred *cred = current_cred(); + struct common_audit_data ad; + struct inode_security_struct *isec; + u32 sid; - return dentry_has_perm(cred, dentry, FILE__READ); + validate_creds(cred); + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + sid = cred_sid(cred); + isec = inode->i_security; + + return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad, + rcu ? MAY_NOT_BLOCK : 0); } static noinline int audit_inode_permission(struct inode *inode, |