Files
zoneminder/tests/zm_image.cpp
SteveGilvarry ee366cdf78 fix: rotate/flip segfault from AV_CEIL_RSHIFT on unsigned dimensions
Image::Rotate and Image::Flip computed chroma plane dimensions with
AV_CEIL_RSHIFT(width, log2_chroma_w). The macro's runtime form is
-((-(a)) >> (b)), which relies on arithmetic right shift of a negative
value and is only valid for signed operands - FFmpeg always passes int.
Image::width/height are unsigned, so the negation wraps, the shift is
logical, and the result is 2^31 + ceil(w/2^b) instead of ceil(w/2^b):
for 1280x720 the chroma rotate received src_w=2147484288 and
src_h=2147484008 (captured in gdb), writing gigabytes out of bounds.

Effect: zmc's decoder thread segfaulted on the first decoded frame of
any monitor with a rotated or flipped orientation and a planar pixel
format - a monitor with decoding Always crash-loops.

Replace the macro at both sites with an explicit unsigned ceiling
shift helper and a comment documenting the trap.

Tests: new tests/zm_image.cpp covers Rotate 90/180/270 and Flip on
YUV420P with per-plane marker pixels, plus odd dimensions exercising
the chroma ceiling. The Rotate cases segfault before this fix (verified,
exit 139) and pass after. Full suite 85/85 via ctest. Live-verified on
a 1280x720 ROTATE_270 monitor with decoding Always: pre-fix crash
within seconds, post-fix 90s clean run under gdb.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-06-11 19:42:52 +10:00

163 lines
6.3 KiB
C++

/*
* This file is part of the ZoneMinder Project. See AUTHORS file for Copyright information
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "zm_catch2.h"
#include "zm_config.h"
#include "zm_image.h"
#include "zm_rgb.h"
extern "C" {
#include <libavutil/imgutils.h>
}
#include <cstring>
namespace {
// Image::Initialise() loads the timestamp font from the DB-backed config,
// which the test binary doesn't have; point it at the test fixture font.
void bootstrap_image_config() {
config.font_file_location = "data/fonts/04_valid.zmfnt";
}
struct Planes {
uint8_t *data[4] = {nullptr, nullptr, nullptr, nullptr};
int stride[4] = {0, 0, 0, 0};
};
// View an Image's buffer with the same layout Image uses internally
// (av_image_fill_arrays, align 32).
Planes plane_view(Image &image, AVPixelFormat fmt, int w, int h) {
Planes planes;
REQUIRE(av_image_fill_arrays(planes.data, planes.stride, image.Buffer(),
fmt, w, h, 32) > 0);
return planes;
}
} // namespace
// Regression: Image::Rotate/Flip computed chroma plane dimensions with
// AV_CEIL_RSHIFT on unsigned operands. The macro's runtime form
// -((-(a)) >> (b)) is only valid for signed types; with unsigned width it
// yields 2^31 + width/2, sending the chroma loops billions of samples out
// of bounds (segfault on every rotated planar image - decoder thread crash
// on any monitor with a rotated orientation).
TEST_CASE("Image::Rotate YUV420P", "[image]") {
bootstrap_image_config();
const int w = 1280, h = 720;
Image image(w, h, ZM_COLOUR_GRAY8, ZM_SUBPIX_ORDER_YUV420P);
REQUIRE(image.Buffer() != nullptr);
// Distinct fill per plane + a marker pixel in each
Planes src = plane_view(image, AV_PIX_FMT_YUV420P, w, h);
memset(src.data[0], 0x10, static_cast<size_t>(src.stride[0]) * h);
memset(src.data[1], 0x20, static_cast<size_t>(src.stride[1]) * (h / 2));
memset(src.data[2], 0x30, static_cast<size_t>(src.stride[2]) * (h / 2));
src.data[0][20 * src.stride[0] + 10] = 200; // luma (10, 20)
src.data[1][30 * src.stride[1] + 40] = 210; // U (40, 30)
src.data[2][50 * src.stride[2] + 60] = 220; // V (60, 50)
SECTION("rotate 90") {
image.Rotate(90);
REQUIRE(image.Width() == static_cast<unsigned int>(h));
REQUIRE(image.Height() == static_cast<unsigned int>(w));
Planes dst = plane_view(image, AV_PIX_FMT_YUV420P, h, w);
// 90deg: (sx, sy) -> (dx, dy) = (src_h-1-sy, sx)
REQUIRE(dst.data[0][10 * dst.stride[0] + (h - 1 - 20)] == 200);
// chroma plane is (w/2 x h/2): (40, 30) -> (h/2-1-30, 40)
REQUIRE(dst.data[1][40 * dst.stride[1] + (h / 2 - 1 - 30)] == 210);
REQUIRE(dst.data[2][60 * dst.stride[2] + (h / 2 - 1 - 50)] == 220);
}
SECTION("rotate 180") {
image.Rotate(180);
REQUIRE(image.Width() == static_cast<unsigned int>(w));
REQUIRE(image.Height() == static_cast<unsigned int>(h));
Planes dst = plane_view(image, AV_PIX_FMT_YUV420P, w, h);
// 180deg: (sx, sy) -> (src_w-1-sx, src_h-1-sy)
REQUIRE(dst.data[0][(h - 1 - 20) * dst.stride[0] + (w - 1 - 10)] == 200);
REQUIRE(dst.data[1][(h / 2 - 1 - 30) * dst.stride[1] + (w / 2 - 1 - 40)] == 210);
REQUIRE(dst.data[2][(h / 2 - 1 - 50) * dst.stride[2] + (w / 2 - 1 - 60)] == 220);
}
SECTION("rotate 270") {
image.Rotate(270);
REQUIRE(image.Width() == static_cast<unsigned int>(h));
REQUIRE(image.Height() == static_cast<unsigned int>(w));
Planes dst = plane_view(image, AV_PIX_FMT_YUV420P, h, w);
// 270deg: (sx, sy) -> (dx, dy) = (sy, src_w-1-sx)
REQUIRE(dst.data[0][(w - 1 - 10) * dst.stride[0] + 20] == 200);
REQUIRE(dst.data[1][(w / 2 - 1 - 40) * dst.stride[1] + 30] == 210);
REQUIRE(dst.data[2][(w / 2 - 1 - 60) * dst.stride[2] + 50] == 220);
}
}
TEST_CASE("Image::Rotate YUV420P odd dimensions", "[image]") {
bootstrap_image_config();
// Odd luma dims exercise the ceiling in the chroma plane size: 101x57
// luma -> 51x29 chroma.
const int w = 101, h = 57;
Image image(w, h, ZM_COLOUR_GRAY8, ZM_SUBPIX_ORDER_YUV420P);
Planes src = plane_view(image, AV_PIX_FMT_YUV420P, w, h);
const int cw = (w + 1) / 2, ch = (h + 1) / 2;
memset(src.data[0], 0x10, static_cast<size_t>(src.stride[0]) * h);
memset(src.data[1], 0x20, static_cast<size_t>(src.stride[1]) * ch);
memset(src.data[2], 0x30, static_cast<size_t>(src.stride[2]) * ch);
// Marker in the LAST chroma column/row - the part flooring would drop
src.data[1][(ch - 1) * src.stride[1] + (cw - 1)] = 211;
image.Rotate(90);
REQUIRE(image.Width() == static_cast<unsigned int>(h));
REQUIRE(image.Height() == static_cast<unsigned int>(w));
Planes dst = plane_view(image, AV_PIX_FMT_YUV420P, h, w);
// (cw-1, ch-1) -> (ch-1-(ch-1), cw-1) = (0, cw-1)
REQUIRE(dst.data[1][(cw - 1) * dst.stride[1] + 0] == 211);
}
TEST_CASE("Image::Flip YUV420P", "[image]") {
bootstrap_image_config();
const int w = 640, h = 480;
Image image(w, h, ZM_COLOUR_GRAY8, ZM_SUBPIX_ORDER_YUV420P);
Planes src = plane_view(image, AV_PIX_FMT_YUV420P, w, h);
memset(src.data[0], 0x10, static_cast<size_t>(src.stride[0]) * h);
memset(src.data[1], 0x20, static_cast<size_t>(src.stride[1]) * (h / 2));
memset(src.data[2], 0x30, static_cast<size_t>(src.stride[2]) * (h / 2));
src.data[0][20 * src.stride[0] + 10] = 200;
src.data[1][30 * src.stride[1] + 40] = 210;
SECTION("horizontal") {
image.Flip(true);
Planes dst = plane_view(image, AV_PIX_FMT_YUV420P, w, h);
REQUIRE(dst.data[0][20 * dst.stride[0] + (w - 1 - 10)] == 200);
REQUIRE(dst.data[1][30 * dst.stride[1] + (w / 2 - 1 - 40)] == 210);
}
SECTION("vertical") {
image.Flip(false);
Planes dst = plane_view(image, AV_PIX_FMT_YUV420P, w, h);
REQUIRE(dst.data[0][(h - 1 - 20) * dst.stride[0] + 10] == 200);
REQUIRE(dst.data[1][(h / 2 - 1 - 30) * dst.stride[1] + 40] == 210);
}
}