diff options
| author | Jan Kiszka <jan.kiszka@siemens.com> | 2013-09-03 18:08:50 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-09-20 12:37:52 +0200 |
| commit | 18e5eec4db96a00907eb588a2b803401637c7f67 (patch) | |
| tree | 07c96ef86554da3b74edadad64acac01876ffce8 | |
| parent | 76fe21dedafb0319306bc993f23e7646b139cfe4 (diff) | |
kvmvapic: Catch invalid ROM size
If not caught early, a zero-length ROM will cause a NULL-pointer access
later on in patch_hypercalls when allocating a zero-length ROM copy and
trying to read from it.
CC: qemu-stable@nongnu.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | hw/i386/kvmvapic.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c index d3a6fbe1f9..c66fbf2fdb 100644 --- a/hw/i386/kvmvapic.c +++ b/hw/i386/kvmvapic.c @@ -578,7 +578,7 @@ static int patch_hypercalls(VAPICROMState *s) * enable write access to the option ROM so that variables can be updated by * the guest. */ -static void vapic_map_rom_writable(VAPICROMState *s) +static int vapic_map_rom_writable(VAPICROMState *s) { hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK; MemoryRegionSection section; @@ -599,6 +599,9 @@ static void vapic_map_rom_writable(VAPICROMState *s) /* read ROM size from RAM region */ ram = memory_region_get_ram_ptr(section.mr); rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE; + if (rom_size == 0) { + return -1; + } s->rom_size = rom_size; /* We need to round to avoid creating subpages @@ -612,11 +615,15 @@ static void vapic_map_rom_writable(VAPICROMState *s) memory_region_add_subregion_overlap(as, rom_paddr, &s->rom, 1000); s->rom_mapped_writable = true; memory_region_unref(section.mr); + + return 0; } static int vapic_prepare(VAPICROMState *s) { - vapic_map_rom_writable(s); + if (vapic_map_rom_writable(s) < 0) { + return -1; + } if (patch_hypercalls(s) < 0) { return -1; |