From: Stephen Wilson Date: Sun, 13 Mar 2011 19:49:21 +0000 (-0400) Subject: proc: disable mem_write after exec X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=26947f8c8f9598209001cdcd31bb2162a2e54691;p=linux-beck.git 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 Signed-off-by: Al Viro --- diff --git a/fs/proc/base.c b/fs/proc/base.c index e94b58b496f1..9af49a3984f1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -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)