From 2785f196318c759d2ba97a36c168e848ec38d362 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 8 Jul 2019 14:11:31 +0100 Subject: [PATCH] tests/migration-test: Fix read off end of aarch64_kernel array MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The test aarch64 kernel is in an array defined with unsigned char aarch64_kernel[] = { [...] } which means it could be any size; currently it's quite small. However we write it to a file using init_bootfile(), which writes exactly 512 bytes to the file. This will break if we ever end up with a kernel larger than that, and will read garbage off the end of the array in the current setup where the kernel is smaller. Make init_bootfile() take an argument giving the length of the data to write. This allows us to use it for all architectures (previously s390 had a special-purpose init_bootfile_s390x which hardcoded the file to write so it could write the correct length). We assert that the x86 bootfile really is exactly 512 bytes as it should be (and as we were previously just assuming it was). This was detected by the clang-7 asan: ==15607==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55a796f51d20 at pc 0x55a796b89c2f bp 0x7ffc58e89160 sp 0x7ffc58e88908 READ of size 512 at 0x55a796f51d20 thread T0 #0 0x55a796b89c2e in fwrite (/home/petmay01/linaro/qemu-from-laptop/qemu/build/sanitizers/tests/migration-test+0xb0c2e) #1 0x55a796c46492 in init_bootfile /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:99:5 #2 0x55a796c46492 in test_migrate_start /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:593 #3 0x55a796c44101 in test_baddest /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:854:9 #4 0x7f906ffd3cc9 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72cc9) #5 0x7f906ffd3bfa (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72bfa) #6 0x7f906ffd3bfa (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72bfa) #7 0x7f906ffd3ea1 in g_test_run_suite (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72ea1) #8 0x7f906ffd3ec0 in g_test_run (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72ec0) #9 0x55a796c43707 in main /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:1187:11 #10 0x7f906e9abb96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310 #11 0x55a796b6c2d9 in _start (/home/petmay01/linaro/qemu-from-laptop/qemu/build/sanitizers/tests/migration-test+0x932d9) Signed-off-by: Peter Maydell Reviewed-by: Laurent Vivier Reviewed-by: Philippe Mathieu-Daudé Message-id: 20190702150311.20467-1-peter.maydell@linaro.org --- tests/migration-test.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) diff --git a/tests/migration-test.c b/tests/migration-test.c index 0cd014dbe5..b6434628e1 100644 --- a/tests/migration-test.c +++ b/tests/migration-test.c @@ -91,23 +91,13 @@ static const char *tmpfs; */ #include "tests/migration/i386/a-b-bootblock.h" #include "tests/migration/aarch64/a-b-kernel.h" - -static void init_bootfile(const char *bootpath, void *content) -{ - FILE *bootfile = fopen(bootpath, "wb"); - - g_assert_cmpint(fwrite(content, 512, 1, bootfile), ==, 1); - fclose(bootfile); -} - #include "tests/migration/s390x/a-b-bios.h" -static void init_bootfile_s390x(const char *bootpath) +static void init_bootfile(const char *bootpath, void *content, size_t len) { FILE *bootfile = fopen(bootpath, "wb"); - size_t len = sizeof(s390x_elf); - g_assert_cmpint(fwrite(s390x_elf, len, 1, bootfile), ==, 1); + g_assert_cmpint(fwrite(content, len, 1, bootfile), ==, 1); fclose(bootfile); } @@ -537,7 +527,9 @@ static int test_migrate_start(QTestState **from, QTestState **to, got_stop = false; bootpath = g_strdup_printf("%s/bootsect", tmpfs); if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) { - init_bootfile(bootpath, x86_bootsect); + /* the assembled x86 boot sector should be exactly one sector large */ + assert(sizeof(x86_bootsect) == 512); + init_bootfile(bootpath, x86_bootsect, sizeof(x86_bootsect)); extra_opts = use_shmem ? get_shmem_opts("150M", shmem_path) : NULL; cmd_src = g_strdup_printf("-machine accel=%s -m 150M" " -name source,debug-threads=on" @@ -555,7 +547,7 @@ static int test_migrate_start(QTestState **from, QTestState **to, start_address = X86_TEST_MEM_START; end_address = X86_TEST_MEM_END; } else if (g_str_equal(arch, "s390x")) { - init_bootfile_s390x(bootpath); + init_bootfile(bootpath, s390x_elf, sizeof(s390x_elf)); extra_opts = use_shmem ? get_shmem_opts("128M", shmem_path) : NULL; cmd_src = g_strdup_printf("-machine accel=%s -m 128M" " -name source,debug-threads=on" @@ -590,7 +582,7 @@ static int test_migrate_start(QTestState **from, QTestState **to, start_address = PPC_TEST_MEM_START; end_address = PPC_TEST_MEM_END; } else if (strcmp(arch, "aarch64") == 0) { - init_bootfile(bootpath, aarch64_kernel); + init_bootfile(bootpath, aarch64_kernel, sizeof(aarch64_kernel)); extra_opts = use_shmem ? get_shmem_opts("150M", shmem_path) : NULL; cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=max " "-name vmsource,debug-threads=on -cpu max " -- 2.11.4.GIT