diff options
| author | Gerd Hoffmann | 2017-10-11 10:43:14 +0200 |
|---|---|---|
| committer | Gerd Hoffmann | 2017-10-17 09:59:00 +0200 |
| commit | eb38e1bc3740725ca29a535351de94107ec58d51 (patch) | |
| tree | dd071fd63e7677672aad985e719672e267f4ded5 | |
| parent | vga: add ram_addr_t cast (diff) | |
| download | qemu-eb38e1bc3740725ca29a535351de94107ec58d51.tar.gz qemu-eb38e1bc3740725ca29a535351de94107ec58d51.tar.xz qemu-eb38e1bc3740725ca29a535351de94107ec58d51.zip | |
cirrus: fix oob access in mode4and5 write functions
Move dst calculation into the loop, so we apply the mask on each
interation and will not overflow vga memory.
Cc: Prasad J Pandit <pjp@fedoraproject.org>
Reported-by: Niu Guoxiang <niuguoxiang@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20171011084314.21752-1-kraxel@redhat.com
| -rw-r--r-- | hw/display/cirrus_vga.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index b4d579857a..bc32bf1e39 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -2038,15 +2038,14 @@ static void cirrus_mem_writeb_mode4and5_8bpp(CirrusVGAState * s, unsigned val = mem_value; uint8_t *dst; - dst = s->vga.vram_ptr + (offset &= s->cirrus_addr_mask); for (x = 0; x < 8; x++) { + dst = s->vga.vram_ptr + ((offset + x) & s->cirrus_addr_mask); if (val & 0x80) { *dst = s->cirrus_shadow_gr1; } else if (mode == 5) { *dst = s->cirrus_shadow_gr0; } val <<= 1; - dst++; } memory_region_set_dirty(&s->vga.vram, offset, 8); } @@ -2060,8 +2059,8 @@ static void cirrus_mem_writeb_mode4and5_16bpp(CirrusVGAState * s, unsigned val = mem_value; uint8_t *dst; - dst = s->vga.vram_ptr + (offset &= s->cirrus_addr_mask); for (x = 0; x < 8; x++) { + dst = s->vga.vram_ptr + ((offset + 2 * x) & s->cirrus_addr_mask & ~1); if (val & 0x80) { *dst = s->cirrus_shadow_gr1; *(dst + 1) = s->vga.gr[0x11]; @@ -2070,7 +2069,6 @@ static void cirrus_mem_writeb_mode4and5_16bpp(CirrusVGAState * s, *(dst + 1) = s->vga.gr[0x10]; } val <<= 1; - dst += 2; } memory_region_set_dirty(&s->vga.vram, offset, 16); } |