From 377179cd28cd417dcfb4396edb824533431e607e Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Fri, 13 Jul 2018 14:05:56 -0400 Subject: security: define new LSM hook named security_kernel_load_data Differentiate between the kernel reading a file specified by userspace from the kernel loading a buffer containing data provided by userspace. This patch defines a new LSM hook named security_kernel_load_data(). Signed-off-by: Mimi Zohar Cc: Eric Biederman Cc: Luis R. Rodriguez Cc: Kees Cook Cc: Casey Schaufler Acked-by: Serge Hallyn Acked-by: Kees Cook Signed-off-by: James Morris --- security/security.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'security/security.c') diff --git a/security/security.c b/security/security.c index 68f46d849abe..c2de2f134854 100644 --- a/security/security.c +++ b/security/security.c @@ -1056,6 +1056,11 @@ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, } EXPORT_SYMBOL_GPL(security_kernel_post_read_file); +int security_kernel_load_data(enum kernel_load_data_id id) +{ + return call_int_hook(kernel_load_data, 0, id); +} + int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { -- cgit v1.2.3 From 16c267aac86b463b1fcccd43c89f4c8e5c5c86fa Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Fri, 13 Jul 2018 14:05:58 -0400 Subject: ima: based on policy require signed kexec kernel images The original kexec_load syscall can not verify file signatures, nor can the kexec image be measured. Based on policy, deny the kexec_load syscall. Signed-off-by: Mimi Zohar Cc: Eric Biederman Cc: Kees Cook Reviewed-by: Kees Cook Signed-off-by: James Morris --- security/security.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'security/security.c') diff --git a/security/security.c b/security/security.c index c2de2f134854..4927e7cc7d96 100644 --- a/security/security.c +++ b/security/security.c @@ -1058,7 +1058,12 @@ EXPORT_SYMBOL_GPL(security_kernel_post_read_file); int security_kernel_load_data(enum kernel_load_data_id id) { - return call_int_hook(kernel_load_data, 0, id); + int ret; + + ret = call_int_hook(kernel_load_data, 0, id); + if (ret) + return ret; + return ima_load_data(id); } int security_task_fix_setuid(struct cred *new, const struct cred *old, -- cgit v1.2.3 From 83a68a06795fa47e77ea758f293a5946e9e02e84 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 17 Jul 2018 22:23:37 +0200 Subject: security: export security_kernel_load_data function The firmware_loader can be built as a loadable module, which now fails when CONFIG_SECURITY is enabled, because a call to the security_kernel_load_data() function got added, and this is not exported to modules: ERROR: "security_kernel_load_data" [drivers/base/firmware_loader/firmware_class.ko] undefined! Add an EXPORT_SYMBOL_GPL() to make it available here. Fixes: 6e852651f28e ("firmware: add call to LSM hook before firmware sysfs fallback") Signed-off-by: Arnd Bergmann Signed-off-by: James Morris --- security/security.c | 1 + 1 file changed, 1 insertion(+) (limited to 'security/security.c') diff --git a/security/security.c b/security/security.c index 4927e7cc7d96..6e149d0ffe33 100644 --- a/security/security.c +++ b/security/security.c @@ -1065,6 +1065,7 @@ int security_kernel_load_data(enum kernel_load_data_id id) return ret; return ima_load_data(id); } +EXPORT_SYMBOL_GPL(security_kernel_load_data); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) -- cgit v1.2.3 From 87ea58433208d17295e200d56be5e2a4fe4ce7d6 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 17 Jul 2018 10:36:04 -0700 Subject: security: check for kstrdup() failure in lsm_append() lsm_append() should return -ENOMEM if memory allocation failed. Fixes: d69dece5f5b6 ("LSM: Add /sys/kernel/security/lsm") Signed-off-by: Eric Biggers Signed-off-by: James Morris --- security/security.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'security/security.c') diff --git a/security/security.c b/security/security.c index 6e149d0ffe33..b49ee810371b 100644 --- a/security/security.c +++ b/security/security.c @@ -118,6 +118,8 @@ static int lsm_append(char *new, char **result) if (*result == NULL) { *result = kstrdup(new, GFP_KERNEL); + if (*result == NULL) + return -ENOMEM; } else { /* Check if it is the last registered name */ if (match_last_lsm(*result, new)) -- cgit v1.2.3