diff options
Diffstat (limited to 'hw/i386')
| -rw-r--r-- | hw/i386/pc_sysfw_ovmf.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/hw/i386/pc_sysfw_ovmf.c b/hw/i386/pc_sysfw_ovmf.c index f4dd92c..07a4c26 100644 --- a/hw/i386/pc_sysfw_ovmf.c +++ b/hw/i386/pc_sysfw_ovmf.c @@ -24,11 +24,14 @@ */ #include "qemu/osdep.h" +#include "qemu/error-report.h" #include "hw/i386/pc.h" #include "cpu.h" #define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d" +static const int bytes_after_table_footer = 32; + static bool ovmf_flash_parsed; static uint8_t *ovmf_table; static int ovmf_table_len; @@ -52,12 +55,13 @@ void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size) /* * if this is OVMF there will be a table footer - * guid 48 bytes before the end of the flash file. If it's - * not found, silently abort the flash parsing. + * guid 48 bytes before the end of the flash file + * (= 32 bytes after the table + 16 bytes the GUID itself). + * If it's not found, silently abort the flash parsing. */ qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid); guid = qemu_uuid_bswap(guid); /* guids are LE */ - ptr = flash_ptr + flash_size - 48; + ptr = flash_ptr + flash_size - (bytes_after_table_footer + sizeof(guid)); if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) { return; } @@ -66,7 +70,13 @@ void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size) ptr -= sizeof(uint16_t); tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t); - if (tot_len <= 0) { + if (tot_len < 0 || tot_len > (ptr - flash_ptr)) { + error_report("OVMF table has invalid size %d", tot_len); + return; + } + + if (tot_len == 0) { + /* no entries in the OVMF table */ return; } |