Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5b282552 authored by Davidlohr Bueso's avatar Davidlohr Bueso Committed by Paul Moore
Browse files

audit: reduce mmap_sem hold for mm->exe_file 



The mm->exe_file is currently serialized with mmap_sem (shared)
in order to both safely (1) read the file and (2) audit it via
audit_log_d_path(). Good users will, on the other hand, make use
of the more standard get_mm_exe_file(), requiring only holding
the mmap_sem to read the value, and relying on reference counting
to make sure that the exe file won't dissapear underneath us.

Additionally, upon NULL return of get_mm_exe_file, we also call
audit_log_format(ab, " exe=(null)").

Signed-off-by: default avatarDavidlohr Bueso <dbueso@suse.de>
[PM: tweaked subject line]
Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
parent 4766b199

kernel/audit.c

+14 −8
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/file.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/atomic.h>
@@ -1851,15 +1852,20 @@ EXPORT_SYMBOL(audit_log_task_context); 
void audit_log_d_path_exe(struct audit_buffer *ab,

			  struct mm_struct *mm)

{

	if (!mm) {

		audit_log_format(ab, " exe=(null)");

		return;

	}

	struct file *exe_file;



	if (!mm)

		goto out_null;



	down_read(&mm->mmap_sem);

	if (mm->exe_file)

		audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);

	up_read(&mm->mmap_sem);

	exe_file = get_mm_exe_file(mm);

	if (!exe_file)

		goto out_null;



	audit_log_d_path(ab, " exe=", &exe_file->f_path);

	fput(exe_file);

	return;

out_null:

	audit_log_format(ab, " exe=(null)");

}



void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)