linux-kernel - [PATCH 6/7] cachefiles: avoid deprecated get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <154359606362.18703.14445019258226218319.stgit@warthog.procyon.org.uk>
Date:   Fri, 30 Nov 2018 16:41:03 +0000
From:   David Howells <dhowells@...hat.com>
To:     torvalds@...ux-foundation.org
Cc:     Arnd Bergmann <arnd@...db.de>, dhowells@...hat.com,
        linux-cachefs@...hat.com, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 6/7] cachefiles: avoid deprecated get_seconds()

From: Arnd Bergmann <arnd@...db.de>

get_seconds() returns an unsigned long can overflow on some architectures
and is deprecated because of that. In cachefs, we cast that number to
a a 32-bit integer, which will overflow in year 2106 on all architectures.

As confirmed by David Howells, the overflow probably isn't harmful
in the end, since the timestamps are only used to make the file names
unique, but they don't strictly have to be in monotonically increasing
order since the files only exist in order to be deleted as quickly
as possible.

Moving to ktime_get_real_seconds() avoids the deprecated interface.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/cachefiles/namei.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 5ab411d4bc59..1645fcfd9691 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -338,7 +338,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
 try_again:
 	/* first step is to make up a grave dentry in the graveyard */
 	sprintf(nbuffer, "%08x%08x",
-		(uint32_t) get_seconds(),
+		(uint32_t) ktime_get_real_seconds(),
 		(uint32_t) atomic_inc_return(&cache->gravecounter));

 	/* do the multiway lock magic */