From: Alexey Dobriyan <adobriyan@gmail.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, eric.dumazet@gmail.com,
xiyou.wangcong@gmail.com, fw@strlen.de
Subject: [PATCH] proc: reject "." and ".." as filenames
Date: Sat, 10 Mar 2018 03:12:23 +0300 [thread overview]
Message-ID: <20180310001223.GB12443@avx2> (raw)
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.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
fs/proc/generic.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -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;
next reply other threads:[~2018-03-10 0:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-10 0:12 Alexey Dobriyan [this message]
2018-03-10 0:19 ` [PATCH] proc: reject "." and ".." as filenames Florian Westphal
2018-03-11 21:30 ` Pavel Machek
2018-03-11 21:35 ` Alexey Dobriyan
2018-03-11 21:41 ` Pavel Machek
2018-03-12 23:00 ` Andrew Morton
2018-03-13 7:20 ` Alexey Dobriyan
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