Fix CVE-2017-14167: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-14167 http://seclists.org/oss-sec/2017/q3/407 Patch copied from upstream development mailing list: https://lists.nongnu.org/archive/html/qemu-devel/2017-09/msg01483.html From: Prasad J Pandit While loading kernel via multiboot-v1 image, (flags & 0x00010000) indicates that multiboot header contains valid addresses to load the kernel image. These addresses are used to compute kernel size and kernel text offset in the OS image. Validate these address values to avoid an OOB access issue. This is CVE-2017-14167. Reported-by: Thomas Garnier Signed-off-by: Prasad J Pandit --- hw/i386/multiboot.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) Update: add CVE-ID to the commit message. diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c index 6001f4caa2..c7b70c91d5 100644 --- a/hw/i386/multiboot.c +++ b/hw/i386/multiboot.c @@ -221,15 +221,34 @@ int load_multiboot(FWCfgState *fw_cfg, uint32_t mh_header_addr = ldl_p(header+i+12); uint32_t mh_load_end_addr = ldl_p(header+i+20); uint32_t mh_bss_end_addr = ldl_p(header+i+24); + mh_load_addr = ldl_p(header+i+16); + if (mh_header_addr < mh_load_addr) { + fprintf(stderr, "invalid mh_load_addr address\n"); + exit(1); + } + uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr); uint32_t mb_load_size = 0; mh_entry_addr = ldl_p(header+i+28); if (mh_load_end_addr) { + if (mh_bss_end_addr < mh_load_addr) { + fprintf(stderr, "invalid mh_bss_end_addr address\n"); + exit(1); + } mb_kernel_size = mh_bss_end_addr - mh_load_addr; + + if (mh_load_end_addr < mh_load_addr) { + fprintf(stderr, "invalid mh_load_end_addr address\n"); + exit(1); + } mb_load_size = mh_load_end_addr - mh_load_addr; } else { + if (kernel_file_size < mb_kernel_text_offset) { + fprintf(stderr, "invalid kernel_file_size\n"); + exit(1); + } mb_kernel_size = kernel_file_size - mb_kernel_text_offset; mb_load_size = mb_kernel_size; } -- 2.13.5