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 --- security/selinux/hooks.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 558beee97d8d..dec654d52b68 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4003,13 +4003,14 @@ static int selinux_kernel_module_from_file(struct file *file) } static int selinux_kernel_read_file(struct file *file, - enum kernel_read_file_id id) + enum kernel_read_file_id id, + bool contents) { int rc = 0; switch (id) { case READING_MODULE: - rc = selinux_kernel_module_from_file(file); + rc = selinux_kernel_module_from_file(contents ? file : NULL); break; default: break; -- cgit