[PATCH 4/5 v4] added LSM hook to call ima_buffer_check

From: Prakhar Srivastava
Date: Fri May 03 2019 - 18:26:15 EST


From: Prakhar Srivastava <prsriva02@xxxxxxxxx>

add a LAM hook for kexec_cmldine args to be made available to
other LSMs.

Signed-off-by: Prakhar Srivastava <prsriva02@xxxxxxxxx>
---
include/linux/lsm_hooks.h | 3 +++
include/linux/security.h | 3 +++
kernel/kexec_internal.h | 4 +++-
security/security.c | 6 ++++++
4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index a240a3fc5fc4..f18562c1eb24 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1672,6 +1672,8 @@ union security_list_options {
int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen);
int (*inode_getsecctx)(struct inode *inode, void **ctx, u32 *ctxlen);

+ int (*buffer_check)(const void *buff, int size, const char *eventname);
+
#ifdef CONFIG_SECURITY_NETWORK
int (*unix_stream_connect)(struct sock *sock, struct sock *other,
struct sock *newsk);
@@ -1945,6 +1947,7 @@ struct security_hook_heads {
struct hlist_head inode_notifysecctx;
struct hlist_head inode_setsecctx;
struct hlist_head inode_getsecctx;
+ struct hlist_head buffer_check;
#ifdef CONFIG_SECURITY_NETWORK
struct hlist_head unix_stream_connect;
struct hlist_head unix_may_send;
diff --git a/include/linux/security.h b/include/linux/security.h
index 49f2685324b0..8dece6da0dda 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -388,6 +388,7 @@ 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);
+void security_buffer_measure(const void *buff, int size, char *eventname);
#else /* CONFIG_SECURITY */

static inline int call_lsm_notifier(enum lsm_event event, void *data)
@@ -1188,6 +1189,8 @@ static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32
{
return -EOPNOTSUPP;
}
+static inline void security_buffer_measure(const void *buff, int size, char *eventname)
+{ }
#endif /* CONFIG_SECURITY */

#ifdef CONFIG_SECURITY_NETWORK
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 48aaf2ac0d0d..9f967fbb5aa0 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -12,7 +12,9 @@ int kimage_load_segment(struct kimage *image, struct kexec_segment *segment);
void kimage_terminate(struct kimage *image);
int kimage_is_destination_range(struct kimage *image,
unsigned long start, unsigned long end);
-
+int kexec_cmdline_prepend_img_name(char **outbuf, int kernel_fd,
+ const char *cmdline_ptr,
+ unsigned long cmdline_len);
extern struct mutex kexec_mutex;

#ifdef CONFIG_KEXEC_FILE
diff --git a/security/security.c b/security/security.c
index 23cbb1a295a3..2b575a40470e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -754,6 +754,12 @@ int security_bprm_check(struct linux_binprm *bprm)
return ima_bprm_check(bprm);
}

+void security_buffer_measure(const void *buff, int size, char *eventname)
+{
+ call_void_hook(buffer_check, buff, size, eventname);
+ return ima_buffer_check(buff, size, eventname);
+}
+
void security_bprm_committing_creds(struct linux_binprm *bprm)
{
call_void_hook(bprm_committing_creds, bprm);
--
2.20.1