From 4971c268b85e1c7a734a61622fc0813c86e2362e Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Tue, 31 Jan 2023 18:42:43 +0100 Subject: ima: Align ima_file_mmap() parameters with mmap_file LSM hook Commit 98de59bfe4b2f ("take calculation of final prot in security_mmap_file() into a helper") moved the code to update prot, to be the actual protections applied to the kernel, to a new helper called mmap_prot(). However, while without the helper ima_file_mmap() was getting the updated prot, with the helper ima_file_mmap() gets the original prot, which contains the protections requested by the application. A possible consequence of this change is that, if an application calls mmap() with only PROT_READ, and the kernel applies PROT_EXEC in addition, that application would have access to executable memory without having this event recorded in the IMA measurement list. This situation would occur for example if the application, before mmap(), calls the personality() system call with READ_IMPLIES_EXEC as the first argument. Align ima_file_mmap() parameters with those of the mmap_file LSM hook, so that IMA can receive both the requested prot and the final prot. Since the requested protections are stored in a new variable, and the final protections are stored in the existing variable, this effectively restores the original behavior of the MMAP_CHECK hook. Cc: stable@vger.kernel.org Fixes: 98de59bfe4b2 ("take calculation of final prot in security_mmap_file() into a helper") Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Signed-off-by: Mimi Zohar --- security/security.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'security/security.c') diff --git a/security/security.c b/security/security.c index d1571900a8c7..174afa4fad81 100644 --- a/security/security.c +++ b/security/security.c @@ -1661,12 +1661,13 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot) int security_mmap_file(struct file *file, unsigned long prot, unsigned long flags) { + unsigned long prot_adj = mmap_prot(file, prot); int ret; - ret = call_int_hook(mmap_file, 0, file, prot, - mmap_prot(file, prot), flags); + + ret = call_int_hook(mmap_file, 0, file, prot, prot_adj, flags); if (ret) return ret; - return ima_file_mmap(file, prot); + return ima_file_mmap(file, prot, prot_adj, flags); } int security_mmap_addr(unsigned long addr) -- cgit v1.2.3-58-ga151