This is a note to let you know that I've just added the patch titled udf: udftime: prevent overflow in udf_disk_stamp_to_time() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: udf-udftime-prevent-overflow-in-udf_disk_stamp_to_ti.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2cb5a53df148e02292bea302fdb294ef2abd7cc1 Author: Roman Smirnov <r.smirnov@xxxxxx> Date: Wed Mar 27 16:27:55 2024 +0300 udf: udftime: prevent overflow in udf_disk_stamp_to_time() [ Upstream commit 3b84adf460381169c085e4bc09e7b57e9e16db0a ] 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 <jack@xxxxxxx> Signed-off-by: Roman Smirnov <r.smirnov@xxxxxx> Reviewed-by: Sergey Shtylyov <s.shtylyov@xxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Message-Id: <20240327132755.13945-1-r.smirnov@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/udf/udftime.c b/fs/udf/udftime.c index fce4ad976c8c2..26169b1f482c3 100644 --- a/fs/udf/udftime.c +++ b/fs/udf/udftime.c @@ -60,13 +60,18 @@ 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