Commit 26947f8c authored Mar 13, 2011 by Stephen Wilson Committed by Al Viro Mar 23, 2011

proc: disable mem_write after exec

This change makes mem_write() observe the same constraints as mem_read(). This
is particularly important for mem_write as an accidental leak of the fd across
an exec could result in arbitrary modification of the target process' memory.
IOW, /proc/pid/mem is implicitly close-on-exec.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 5ddd36b9

fs/proc/base.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -850,6 +850,10 @@ static ssize_t mem_write(struct file * file, const char __user *buf,
		if (check_mem_permission(task))
		goto out;

		copied = -EIO;
		if (file->private_data != (void *)((long)current->self_exec_id))
		goto out;

		copied = -ENOMEM;
		page = (char *)__get_free_page(GFP_TEMPORARY);
		if (!page)