From 2039bda1fa8dad3f4275b29eeaffef545bcbc85d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 2 Oct 2020 10:38:23 -0700 Subject: LSM: Add "contents" flag to kernel_read_file hook As with the kernel_load_data LSM hook, add a "contents" flag to the kernel_read_file LSM hook that indicates whether the LSM can expect a matching call to the kernel_post_read_file LSM hook with the full contents of the file. With the coming addition of partial file read support for kernel_read_file*() API, the LSM will no longer be able to always see the entire contents of a file during the read calls. For cases where the LSM must read examine the complete file contents, it will need to do so on its own every time the kernel_read_file hook is called with contents=false (or reject such cases). Adjust all existing LSMs to retain existing behavior. Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman --- include/linux/security.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index 51c8e4e6b7cc..bc2725491560 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -391,7 +391,8 @@ int security_kernel_load_data(enum kernel_load_data_id id, bool contents); int security_kernel_post_load_data(char *buf, loff_t size, enum kernel_load_data_id id, char *description); -int security_kernel_read_file(struct file *file, enum kernel_read_file_id id); +int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, + bool contents); int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id); int security_task_fix_setuid(struct cred *new, const struct cred *old, @@ -1030,7 +1031,8 @@ static inline int security_kernel_post_load_data(char *buf, loff_t size, } static inline int security_kernel_read_file(struct file *file, - enum kernel_read_file_id id) + enum kernel_read_file_id id, + bool contents) { return 0; } -- cgit v1.2.3