linux-kernel - [PATCH] rtc: hctosys: Add missing range error reporting

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-next>] [day] [month] [year] [list]

Date:   Mon, 5 Nov 2018 03:48:25 +0000 (GMT)
From:   "Maciej W. Rozycki" <macro@...ux-mips.org>
To:     Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>
cc:     linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org,
        stable@...r.kernel.org
Subject: [PATCH] rtc: hctosys: Add missing range error reporting

Fix an issue with the 32-bit range error path in `rtc_hctosys' where no 
error code is set and consequently the successful preceding call result 
from `rtc_read_time' is propagated to `rtc_hctosys_ret'.  This in turn 
makes any subsequent call to `hctosys_show' incorrectly report in sysfs 
that the system time has been set from this RTC while it has not.

Set the error to ERANGE then if we can't express the result due to an 
overflow.

Signed-off-by: Maciej W. Rozycki <macro@...ux-mips.org>
Fixes: b3a5ac42ab18 ("rtc: hctosys: Ensure system time doesn't overflow time_t")
Cc: stable@...r.kernel.org # 4.17+
---
 drivers/rtc/hctosys.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

linux-rtc-hctosys-range.diff
Index: linux-20181008-swarm64-eb/drivers/rtc/hctosys.c
===================================================================
--- linux-20181008-swarm64-eb.orig/drivers/rtc/hctosys.c
+++ linux-20181008-swarm64-eb/drivers/rtc/hctosys.c
@@ -50,8 +50,10 @@ static int __init rtc_hctosys(void)
 	tv64.tv_sec = rtc_tm_to_time64(&tm);
 
 #if BITS_PER_LONG == 32
-	if (tv64.tv_sec > INT_MAX)
+	if (tv64.tv_sec > INT_MAX) {
+		err = -ERANGE;
 		goto err_read;
+	}
 #endif
 
 	err = do_settimeofday64(&tv64);