linux-kernel - [PATCH 5.4 054/203] netfilter: nft_meta: use 64-bit time arithmetic

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: <20200116231748.691052760@linuxfoundation.org>
Date:   Fri, 17 Jan 2020 00:16:11 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Arnd Bergmann <arnd@...db.de>,
        Phil Sutter <phil@....cc>,
        Pablo Neira Ayuso <pablo@...filter.org>
Subject: [PATCH 5.4 054/203] netfilter: nft_meta: use 64-bit time arithmetic

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

commit 6408c40c39d8eee5caaf97f5219b7dd4e041cc59 upstream.

On 32-bit architectures, get_seconds() returns an unsigned 32-bit
time value, which also matches the type used in the nft_meta
code. This will not overflow in year 2038 as a time_t would, but
it still suffers from the overflow problem later on in year 2106.

Change this instance to use the time64_t type consistently
and avoid the deprecated get_seconds().

The nft_meta_weekday() calculation potentially gets a little slower
on 32-bit architectures, but now it has the same behavior as on
64-bit architectures and does not overflow.

Fixes: 63d10e12b00d ("netfilter: nft_meta: support for time matching")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
Acked-by: Phil Sutter <phil@....cc>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 net/netfilter/nft_meta.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -33,19 +33,19 @@
 
 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);
 
-static u8 nft_meta_weekday(unsigned long secs)
+static u8 nft_meta_weekday(time64_t secs)
 {
 	unsigned int dse;
 	u8 wday;
 
 	secs -= NFT_META_SECS_PER_MINUTE * sys_tz.tz_minuteswest;
-	dse = secs / NFT_META_SECS_PER_DAY;
+	dse = div_u64(secs, NFT_META_SECS_PER_DAY);
 	wday = (4 + dse) % NFT_META_DAYS_PER_WEEK;
 
 	return wday;
 }
 
-static u32 nft_meta_hour(unsigned long secs)
+static u32 nft_meta_hour(time64_t secs)
 {
 	struct tm tm;
 
@@ -250,10 +250,10 @@ void nft_meta_get_eval(const struct nft_
 		nft_reg_store64(dest, ktime_get_real_ns());
 		break;
 	case NFT_META_TIME_DAY:
-		nft_reg_store8(dest, nft_meta_weekday(get_seconds()));
+		nft_reg_store8(dest, nft_meta_weekday(ktime_get_real_seconds()));
 		break;
 	case NFT_META_TIME_HOUR:
-		*dest = nft_meta_hour(get_seconds());
+		*dest = nft_meta_hour(ktime_get_real_seconds());
 		break;
 	default:
 		WARN_ON(1);