From: David Gow Date: Wed, 19 Oct 2022 07:32:40 +0000 (+0800) Subject: drm: tests: Fix a buffer overflow in format_helper_test X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7089003304c67658caead22f841840fc4a26b198;p=linux.git drm: tests: Fix a buffer overflow in format_helper_test The xrgb2101010 format conversion test (unlike for other formats) does an endianness conversion on the results. However, it always converts TEST_BUF_SIZE 32-bit integers, which results in reading from (and writing to) more memory than in present in the result buffer. Instead, use the buffer size, divided by sizeof(u32). The issue could be reproduced with KASAN: ./tools/testing/kunit/kunit.py run --kunitconfig drivers/gpu/drm/tests \ --kconfig_add CONFIG_KASAN=y --kconfig_add CONFIG_KASAN_VMALLOC=y \ --kconfig_add CONFIG_KASAN_KUNIT_TEST=y \ drm_format_helper_test.*xrgb2101010 Reported-by: Linux Kernel Functional Testing Fixes: 453114319699 ("drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_xrgb2101010()") Signed-off-by: David Gow Reviewed-by: Maíra Canal Reviewed-by: Javier Martinez Canillas Reviewed-by: José Expósito Signed-off-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20221019073239.3779180-1-davidgow@google.com --- diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c index 8d86c250c2ecb..2191e57f22972 100644 --- a/drivers/gpu/drm/tests/drm_format_helper_test.c +++ b/drivers/gpu/drm/tests/drm_format_helper_test.c @@ -438,7 +438,7 @@ static void drm_test_fb_xrgb8888_to_xrgb2101010(struct kunit *test) iosys_map_set_vaddr(&src, xrgb8888); drm_fb_xrgb8888_to_xrgb2101010(&dst, &result->dst_pitch, &src, &fb, ¶ms->clip); - buf = le32buf_to_cpu(test, buf, TEST_BUF_SIZE); + buf = le32buf_to_cpu(test, buf, dst_size / sizeof(u32)); KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0); }