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authorAlexey Dobriyan <adobriyan@gmail.com>2018-04-10 16:32:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-11 10:28:34 -0700
commitb77d70db659ad3aa662c80cff4475e773a531fbe (patch)
tree453429d7d9b3ac146a5a76247a10ed5695e69c8b /fs/proc
parent5de3d401b79486b9323e1be30e3a34c2437b8800 (diff)
downloadlinux-b77d70db659ad3aa662c80cff4475e773a531fbe.tar.bz2
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>
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/generic.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 800247a256c9..5dad2e89007b 100644
--- 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;