Commit b77d70db authored Apr 10, 2018 by Alexey Dobriyan Committed by Linus Torvalds Apr 11, 2018

proc: reject "." and ".." as filenames

Various subsystems can create files and directories in /proc with names
directly controlled by userspace.

Which means "/", "." and ".." are no-no.

"/" split is already taken care of, do the other 2 prohibited names.

Link: http://lkml.kernel.org/r/20180310001223.GB12443@avx2


Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 5de3d401

fs/proc/generic.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -366,6 +366,14 @@ static struct proc_dir_entry __proc_create(struct proc_dir_entry *parent,
		WARN(1, "name len %u\n", qstr.len);
		return NULL;
		}
		if (qstr.len == 1 && fn[0] == '.') {
		WARN(1, "name '.'\n");
		return NULL;
		}
		if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') {
		WARN(1, "name '..'\n");
		return NULL;
		}
		if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
		WARN(1, "create '/proc/%s' by hand\n", qstr.name);
		return NULL;