Commit bc452b4b authored Jul 30, 2012 by Djalal Harouni Committed by Linus Torvalds Jul 30, 2012

proc: do not allow negative offsets on /proc/<pid>/environ



__mem_open() which is called by both /proc/<pid>/environ and
/proc/<pid>/mem ->open() handlers will allow the use of negative offsets.
/proc/<pid>/mem has negative offsets but not /proc/<pid>/environ.

Clean this by moving the 'force FMODE_UNSIGNED_OFFSET flag' to mem_open()
to allow negative offsets only on /proc/<pid>/mem.

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Brad Spengler <spender@grsecurity.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e8905ec2

fs/proc/base.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -695,8 +695,6 @@ static int __mem_open(struct inode inode, struct file file, unsigned int mode)
		mmput(mm);
		}

		/* OK to pass negative loff_t, we can catch out-of-range */
		file->f_mode \|= FMODE_UNSIGNED_OFFSET;
		file->private_data = mm;

		return 0;
		@@ -704,7 +702,12 @@ static int __mem_open(struct inode inode, struct file file, unsigned int mode)

		static int mem_open(struct inode inode, struct file file)
		{
		return __mem_open(inode, file, PTRACE_MODE_ATTACH);
		int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);

		/* OK to pass negative loff_t, we can catch out-of-range */
		file->f_mode \|= FMODE_UNSIGNED_OFFSET;

		return ret;
		}

		static ssize_t mem_rw(struct file file, char __user buf,

Admin message