From 4da6daf4d3df5a977e4623963f141a627fd2efce Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 10 Jul 2014 10:17:48 -0400 Subject: selinux: fix the default socket labeling in sock_graft() The sock_graft() hook has special handling for AF_INET, AF_INET, and AF_UNIX sockets as those address families have special hooks which label the sock before it is attached its associated socket. Unfortunately, the sock_graft() hook was missing a default approach to labeling sockets which meant that any other address family which made use of connections or the accept() syscall would find the returned socket to be in an "unlabeled" state. This was recently demonstrated by the kcrypto/AF_ALG subsystem and the newly released cryptsetup package (cryptsetup v1.6.5 and later). This patch preserves the special handling in selinux_sock_graft(), but adds a default behavior - setting the sock's label equal to the associated socket - which resolves the problem with AF_ALG and presumably any other address family which makes use of accept(). Cc: stable@vger.kernel.org Signed-off-by: Paul Moore Tested-by: Milan Broz --- include/linux/security.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index 6478ce3252c7..794be735ff4b 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -987,7 +987,10 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Retrieve the LSM-specific secid for the sock to enable caching of network * authorizations. * @sock_graft: - * Sets the socket's isec sid to the sock's sid. + * This hook is called in response to a newly created sock struct being + * grafted onto an existing socket and allows the security module to + * perform whatever security attribute management is necessary for both + * the sock and socket. * @inet_conn_request: * Sets the openreq's sid to socket's sid with MLS portion taken from peer sid. * @inet_csk_clone: -- cgit v1.2.3 From 13752fe2d7f2d41c2fd92a5d1b1c6e38c4de0c05 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 25 Feb 2014 10:28:04 -0800 Subject: security: introduce kernel_fw_from_file hook In order to validate the contents of firmware being loaded, there must be a hook to evaluate any loaded firmware that wasn't built into the kernel itself. Without this, there is a risk that a root user could load malicious firmware designed to mount an attack against kernel memory (e.g. via DMA). Signed-off-by: Kees Cook Reviewed-by: Takashi Iwai --- include/linux/security.h | 17 +++++++++++++++++ security/capability.c | 6 ++++++ security/security.c | 6 ++++++ 3 files changed, 29 insertions(+) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index 59820f8782a1..0ae4b147718a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -702,6 +702,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @inode points to the inode to use as a reference. * The current task must be the one that nominated @inode. * Return 0 if successful. + * @kernel_fw_from_file: + * Load firmware from userspace (not called for built-in firmware). + * @file contains the file structure pointing to the file containing + * the firmware to load. This argument will be NULL if the firmware + * was loaded via the uevent-triggered blob-based interface exposed + * by CONFIG_FW_LOADER_USER_HELPER. + * @buf pointer to buffer containing firmware contents. + * @size length of the firmware contents. + * Return 0 if permission is granted. * @kernel_module_request: * Ability to trigger the kernel to automatically upcall to userspace for * userspace to load a kernel module with the given name. @@ -1568,6 +1577,7 @@ struct security_operations { void (*cred_transfer)(struct cred *new, const struct cred *old); int (*kernel_act_as)(struct cred *new, u32 secid); int (*kernel_create_files_as)(struct cred *new, struct inode *inode); + int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size); int (*kernel_module_request)(char *kmod_name); int (*kernel_module_from_file)(struct file *file); int (*task_fix_setuid) (struct cred *new, const struct cred *old, @@ -1840,6 +1850,7 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_transfer_creds(struct cred *new, const struct cred *old); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); +int security_kernel_fw_from_file(struct file *file, char *buf, size_t size); int security_kernel_module_request(char *kmod_name); int security_kernel_module_from_file(struct file *file); int security_task_fix_setuid(struct cred *new, const struct cred *old, @@ -2366,6 +2377,12 @@ static inline int security_kernel_create_files_as(struct cred *cred, return 0; } +static inline int security_kernel_fw_from_file(struct file *file, + char *buf, size_t size) +{ + return 0; +} + static inline int security_kernel_module_request(char *kmod_name) { return 0; diff --git a/security/capability.c b/security/capability.c index e76373de3129..a74fde6a7468 100644 --- a/security/capability.c +++ b/security/capability.c @@ -401,6 +401,11 @@ static int cap_kernel_create_files_as(struct cred *new, struct inode *inode) return 0; } +static int cap_kernel_fw_from_file(struct file *file, char *buf, size_t size) +{ + return 0; +} + static int cap_kernel_module_request(char *kmod_name) { return 0; @@ -1015,6 +1020,7 @@ void __init security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, cred_transfer); set_to_cap_if_null(ops, kernel_act_as); set_to_cap_if_null(ops, kernel_create_files_as); + set_to_cap_if_null(ops, kernel_fw_from_file); set_to_cap_if_null(ops, kernel_module_request); set_to_cap_if_null(ops, kernel_module_from_file); set_to_cap_if_null(ops, task_fix_setuid); diff --git a/security/security.c b/security/security.c index 31614e9e96e5..35d37d0f0d49 100644 --- a/security/security.c +++ b/security/security.c @@ -845,6 +845,12 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode) return security_ops->kernel_create_files_as(new, inode); } +int security_kernel_fw_from_file(struct file *file, char *buf, size_t size) +{ + return security_ops->kernel_fw_from_file(file, buf, size); +} +EXPORT_SYMBOL_GPL(security_kernel_fw_from_file); + int security_kernel_module_request(char *kmod_name) { return security_ops->kernel_module_request(kmod_name); -- cgit v1.2.3 From 2873ead7e46694910ac49c3a8ee0f54956f96e0c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 28 Jul 2014 10:42:48 -0400 Subject: Revert "selinux: fix the default socket labeling in sock_graft()" This reverts commit 4da6daf4d3df5a977e4623963f141a627fd2efce. Unfortunately, the commit in question caused problems with Bluetooth devices, specifically it caused them to get caught in the newly created BUG_ON() check. The AF_ALG problem still exists, but will be addressed in a future patch. Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- include/linux/security.h | 5 +---- security/selinux/hooks.c | 13 ++----------- 2 files changed, 3 insertions(+), 15 deletions(-) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index 794be735ff4b..6478ce3252c7 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -987,10 +987,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Retrieve the LSM-specific secid for the sock to enable caching of network * authorizations. * @sock_graft: - * This hook is called in response to a newly created sock struct being - * grafted onto an existing socket and allows the security module to - * perform whatever security attribute management is necessary for both - * the sock and socket. + * Sets the socket's isec sid to the sock's sid. * @inet_conn_request: * Sets the openreq's sid to socket's sid with MLS portion taken from peer sid. * @inet_csk_clone: diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b3a6754e932b..336f0a04450e 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4499,18 +4499,9 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent) struct inode_security_struct *isec = SOCK_INODE(parent)->i_security; struct sk_security_struct *sksec = sk->sk_security; - switch (sk->sk_family) { - case PF_INET: - case PF_INET6: - case PF_UNIX: + if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || + sk->sk_family == PF_UNIX) isec->sid = sksec->sid; - break; - default: - /* by default there is no special labeling mechanism for the - * sksec label so inherit the label from the parent socket */ - BUG_ON(sksec->sid != SECINITSID_UNLABELED); - sksec->sid = isec->sid; - } sksec->sclass = isec->sclass; } -- cgit v1.2.3