From 2764040785b3400e3aafab74b8448ad24e8ae14d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Fri, 9 Mar 2018 17:09:44 +0000 Subject: [PATCH] arm: avoid heap-buffer-overflow in load_aarch64_image MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Spotted by ASAN: elmarco@boraha:~/src/qemu/build (master *%)$ QTEST_QEMU_BINARY=aarch64-softmmu/qemu-system-aarch64 tests/boot-serial-test /aarch64/boot-serial/virt: ** (process:19740): DEBUG: 18:39:30.275: foo /tmp/qtest-boot-serial-cXaS94D ================================================================= ==19740==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000069648 at pc 0x7f1d2201cc54 bp 0x7fff331f6a40 sp 0x7fff331f61e8 READ of size 4 at 0x603000069648 thread T0 #0 0x7f1d2201cc53 (/lib64/libasan.so.4+0xafc53) #1 0x55bc86685ee3 in load_aarch64_image /home/elmarco/src/qemu/hw/arm/boot.c:894 #2 0x55bc86687217 in arm_load_kernel_notify /home/elmarco/src/qemu/hw/arm/boot.c:1047 #3 0x55bc877363b5 in notifier_list_notify /home/elmarco/src/qemu/util/notify.c:40 #4 0x55bc869331ea in qemu_run_machine_init_done_notifiers /home/elmarco/src/qemu/vl.c:2716 #5 0x55bc8693bc39 in main /home/elmarco/src/qemu/vl.c:4679 #6 0x7f1d1652c009 in __libc_start_main (/lib64/libc.so.6+0x21009) #7 0x55bc86255cc9 in _start (/home/elmarco/src/qemu/build/aarch64-softmmu/qemu-system-aarch64+0x1ae5cc9) Signed-off-by: Marc-André Lureau Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/arm/boot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/arm/boot.c b/hw/arm/boot.c index 784d301683..196c7fb242 100644 --- a/hw/arm/boot.c +++ b/hw/arm/boot.c @@ -891,7 +891,8 @@ static uint64_t load_aarch64_image(const char *filename, hwaddr mem_base, } /* check the arm64 magic header value -- very old kernels may not have it */ - if (memcmp(buffer + ARM64_MAGIC_OFFSET, "ARM\x64", 4) == 0) { + if (size > ARM64_MAGIC_OFFSET + 4 && + memcmp(buffer + ARM64_MAGIC_OFFSET, "ARM\x64", 4) == 0) { uint64_t hdrvals[2]; /* The arm64 Image header has text_offset and image_size fields at 8 and