From 3b84adf460381169c085e4bc09e7b57e9e16db0a Mon Sep 17 00:00:00 2001 From: Roman Smirnov Date: Wed, 27 Mar 2024 16:27:55 +0300 Subject: [PATCH] udf: udftime: prevent overflow in udf_disk_stamp_to_time() An overflow can occur in a situation where src.centiseconds takes the value of 255. This situation is unlikely, but there is no validation check anywere in the code. Found by Linux Verification Center (linuxtesting.org) with Svace. Suggested-by: Jan Kara Signed-off-by: Roman Smirnov Reviewed-by: Sergey Shtylyov Signed-off-by: Jan Kara Message-Id: <20240327132755.13945-1-r.smirnov@omp.ru> --- fs/udf/udftime.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/udf/udftime.c b/fs/udf/udftime.c index 758163af39c2..78ecc633606f 100644 --- a/fs/udf/udftime.c +++ b/fs/udf/udftime.c @@ -46,13 +46,18 @@ udf_disk_stamp_to_time(struct timespec64 *dest, struct timestamp src) dest->tv_sec = mktime64(year, src.month, src.day, src.hour, src.minute, src.second); dest->tv_sec -= offset * 60; - dest->tv_nsec = 1000 * (src.centiseconds * 10000 + - src.hundredsOfMicroseconds * 100 + src.microseconds); + /* * Sanitize nanosecond field since reportedly some filesystems are * recorded with bogus sub-second values. */ - dest->tv_nsec %= NSEC_PER_SEC; + if (src.centiseconds < 100 && src.hundredsOfMicroseconds < 100 && + src.microseconds < 100) { + dest->tv_nsec = 1000 * (src.centiseconds * 10000 + + src.hundredsOfMicroseconds * 100 + src.microseconds); + } else { + dest->tv_nsec = 0; + } } void