From c5bd64ea146162967c29bd2af0cbb845ba3eaaaf Mon Sep 17 00:00:00 2001 From: Young_X Date: Fri, 23 Nov 2018 14:47:36 +0800 Subject: [PATCH] [MJ2] To avoid divisions by zero / undefined behaviour on shift Signed-off-by: Young_X --- src/lib/openmj2/pi.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/src/lib/openmj2/pi.c b/src/lib/openmj2/pi.c index d0fdb9b1..ce9c16e4 100644 --- a/src/lib/openmj2/pi.c +++ b/src/lib/openmj2/pi.c @@ -224,6 +224,13 @@ static opj_bool pi_next_rpcl(opj_pi_iterator_t * pi) try1 = int_ceildiv(pi->ty1, comp->dy << levelno); rpx = res->pdx + levelno; rpy = res->pdy + levelno; + + /* To avoid divisions by zero / undefined behaviour on shift */ + if (rpx >= 31 || ((comp->dx << rpx) >> rpx) != comp->dx || + rpy >= 31 || ((comp->dy << rpy) >> rpy) != comp->dy) { + continue; + } + if (!((pi->y % (comp->dy << rpy) == 0) || ((pi->y == pi->ty0) && ((try0 << levelno) % (1 << rpy))))) { continue; @@ -317,6 +324,13 @@ static opj_bool pi_next_pcrl(opj_pi_iterator_t * pi) try1 = int_ceildiv(pi->ty1, comp->dy << levelno); rpx = res->pdx + levelno; rpy = res->pdy + levelno; + + /* To avoid divisions by zero / undefined behaviour on shift */ + if (rpx >= 31 || ((comp->dx << rpx) >> rpx) != comp->dx || + rpy >= 31 || ((comp->dy << rpy) >> rpy) != comp->dy) { + continue; + } + if (!((pi->y % (comp->dy << rpy) == 0) || ((pi->y == pi->ty0) && ((try0 << levelno) % (1 << rpy))))) { continue; @@ -408,6 +422,13 @@ static opj_bool pi_next_cprl(opj_pi_iterator_t * pi) try1 = int_ceildiv(pi->ty1, comp->dy << levelno); rpx = res->pdx + levelno; rpy = res->pdy + levelno; + + /* To avoid divisions by zero / undefined behaviour on shift */ + if (rpx >= 31 || ((comp->dx << rpx) >> rpx) != comp->dx || + rpy >= 31 || ((comp->dy << rpy) >> rpy) != comp->dy) { + continue; + } + if (!((pi->y % (comp->dy << rpy) == 0) || ((pi->y == pi->ty0) && ((try0 << levelno) % (1 << rpy))))) { continue; -- 2.30.2