From 6f3be9f562e3027c77bc4482ccf2cea8600a7f74 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Thu, 24 Dec 2015 11:09:40 -0500 Subject: security: Add hook to invalidate inode security labels Add a hook to invalidate an inode's security label when the cached information becomes invalid. Add the new hook in selinux: set a flag when a security label becomes invalid. Signed-off-by: Andreas Gruenbacher Reviewed-by: James Morris Acked-by: Stephen Smalley Signed-off-by: Paul Moore diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 4c48227..71969de 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1261,6 +1261,10 @@ * audit_rule_init. * @rule contains the allocated rule * + * @inode_invalidate_secctx: + * Notify the security module that it must revalidate the security context + * of an inode. + * * @inode_notifysecctx: * Notify the security module of what the security context of an inode * should be. Initializes the incore security context managed by the @@ -1516,6 +1520,7 @@ union security_list_options { int (*secctx_to_secid)(const char *secdata, u32 seclen, u32 *secid); void (*release_secctx)(char *secdata, u32 seclen); + void (*inode_invalidate_secctx)(struct inode *inode); int (*inode_notifysecctx)(struct inode *inode, void *ctx, u32 ctxlen); int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen); int (*inode_getsecctx)(struct inode *inode, void **ctx, u32 *ctxlen); @@ -1757,6 +1762,7 @@ struct security_hook_heads { struct list_head secid_to_secctx; struct list_head secctx_to_secid; struct list_head release_secctx; + struct list_head inode_invalidate_secctx; struct list_head inode_notifysecctx; struct list_head inode_setsecctx; struct list_head inode_getsecctx; diff --git a/include/linux/security.h b/include/linux/security.h index e79149a..4824a4c 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -353,6 +353,7 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); void security_release_secctx(char *secdata, u32 seclen); +void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); @@ -1093,6 +1094,10 @@ static inline void security_release_secctx(char *secdata, u32 seclen) { } +static inline void security_inode_invalidate_secctx(struct inode *inode) +{ +} + static inline int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) { return -EOPNOTSUPP; diff --git a/security/security.c b/security/security.c index c5beb7e..e8ffd92 100644 --- a/security/security.c +++ b/security/security.c @@ -1161,6 +1161,12 @@ void security_release_secctx(char *secdata, u32 seclen) } EXPORT_SYMBOL(security_release_secctx); +void security_inode_invalidate_secctx(struct inode *inode) +{ + call_void_hook(inode_invalidate_secctx, inode); +} +EXPORT_SYMBOL(security_inode_invalidate_secctx); + int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) { return call_int_hook(inode_notifysecctx, 0, inode, ctx, ctxlen); @@ -1763,6 +1769,8 @@ struct security_hook_heads security_hook_heads = { LIST_HEAD_INIT(security_hook_heads.secctx_to_secid), .release_secctx = LIST_HEAD_INIT(security_hook_heads.release_secctx), + .inode_invalidate_secctx = + LIST_HEAD_INIT(security_hook_heads.inode_invalidate_secctx), .inode_notifysecctx = LIST_HEAD_INIT(security_hook_heads.inode_notifysecctx), .inode_setsecctx = diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 1dc0d79..ef3bd9d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -820,7 +820,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, goto out; root_isec->sid = rootcontext_sid; - root_isec->initialized = 1; + root_isec->initialized = LABEL_INITIALIZED; } if (defcontext_sid) { @@ -1308,11 +1308,11 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent unsigned len = 0; int rc = 0; - if (isec->initialized) + if (isec->initialized == LABEL_INITIALIZED) goto out; mutex_lock(&isec->lock); - if (isec->initialized) + if (isec->initialized == LABEL_INITIALIZED) goto out_unlock; sbsec = inode->i_sb->s_security; @@ -1484,7 +1484,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent break; } - isec->initialized = 1; + isec->initialized = LABEL_INITIALIZED; out_unlock: mutex_unlock(&isec->lock); @@ -2790,7 +2790,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, struct inode_security_struct *isec = inode->i_security; isec->sclass = inode_mode_to_security_class(inode->i_mode); isec->sid = newsid; - isec->initialized = 1; + isec->initialized = LABEL_INITIALIZED; } if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT)) @@ -3089,7 +3089,7 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, isec->sclass = inode_mode_to_security_class(inode->i_mode); isec->sid = newsid; - isec->initialized = 1; + isec->initialized = LABEL_INITIALIZED; return; } @@ -3183,7 +3183,7 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, isec->sclass = inode_mode_to_security_class(inode->i_mode); isec->sid = newsid; - isec->initialized = 1; + isec->initialized = LABEL_INITIALIZED; return 0; } @@ -3761,7 +3761,7 @@ static void selinux_task_to_inode(struct task_struct *p, u32 sid = task_sid(p); isec->sid = sid; - isec->initialized = 1; + isec->initialized = LABEL_INITIALIZED; } /* Returns error only if unable to parse addresses */ @@ -4092,7 +4092,7 @@ static int selinux_socket_post_create(struct socket *sock, int family, return err; } - isec->initialized = 1; + isec->initialized = LABEL_INITIALIZED; if (sock->sk) { sksec = sock->sk->sk_security; @@ -4283,7 +4283,7 @@ static int selinux_socket_accept(struct socket *sock, struct socket *newsock) isec = inode_security(SOCK_INODE(sock)); newisec->sclass = isec->sclass; newisec->sid = isec->sid; - newisec->initialized = 1; + newisec->initialized = LABEL_INITIALIZED; return 0; } @@ -5775,6 +5775,15 @@ static void selinux_release_secctx(char *secdata, u32 seclen) kfree(secdata); } +static void selinux_inode_invalidate_secctx(struct inode *inode) +{ + struct inode_security_struct *isec = inode->i_security; + + mutex_lock(&isec->lock); + isec->initialized = LABEL_INVALID; + mutex_unlock(&isec->lock); +} + /* * called with inode->i_mutex locked */ @@ -6006,6 +6015,7 @@ static struct security_hook_list selinux_hooks[] = { LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx), LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid), LSM_HOOK_INIT(release_secctx, selinux_release_secctx), + LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx), LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx), LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx), LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx), diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 81fa718..a2ae054 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -37,6 +37,12 @@ struct task_security_struct { u32 sockcreate_sid; /* fscreate SID */ }; +enum label_initialized { + LABEL_MISSING, /* not initialized */ + LABEL_INITIALIZED, /* inizialized */ + LABEL_INVALID /* invalid */ +}; + struct inode_security_struct { struct inode *inode; /* back pointer to inode object */ union { -- cgit v0.10.2