diff options
| author | Daniel Verkamp <daniel@drv.nu> | 2024-03-07 01:08:27 -0800 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2024-03-10 13:00:27 -0400 |
| commit | 5d87ff2542c1116e07ae74ba84197a0013e08db1 (patch) | |
| tree | 416c8e3407d42b985243336850da5aca5af873c1 | |
| parent | 163fd9f0872f95366cfe34eb11568934c2d2fe29 (diff) | |
| download | seabios-5d87ff2542c1116e07ae74ba84197a0013e08db1.tar.gz | |
vbe: Add VBE 2.0+ OemData field to struct vbe_info
Per the VBE 2.0 specification, the VBE controller information is 512
bytes long when the "VBE2" signature is provided, instead of the
original 256 bytes.
src/bootsplash.c uses the original pre-VBE-2.0 256-byte structure while
also filling in the "VBE2" signature, so a video BIOS that makes use of
the VBE2 OemData area could write past the end of the allocated region.
The original bootsplash code did not have this bug; it was introduced
when the bootsplash VBE structures were merged with the VGA ROM struct
definitions.
Fixes: 69e941c159ed ("Merge bootsplash and VGA ROM vbe structure definitions")
Signed-off-by: Daniel Verkamp <daniel@drv.nu>
| -rw-r--r-- | src/std/vbe.h | 2 | ||||
| -rw-r--r-- | vgasrc/vbe.c | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/src/std/vbe.h b/src/std/vbe.h index 94b4ad86..fe96f5ec 100644 --- a/src/std/vbe.h +++ b/src/std/vbe.h @@ -18,6 +18,8 @@ struct vbe_info { struct segoff_s oem_product_string; struct segoff_s oem_revision_string; u8 reserved[222]; + /* VBE 2.0 */ + u8 oem_data[256]; } PACKED; struct vbe_mode_info { diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c index 66afb011..91abc9ab 100644 --- a/vgasrc/vbe.c +++ b/vgasrc/vbe.c @@ -32,16 +32,18 @@ vbe_104f00(struct bregs *regs) { u16 seg = regs->es; struct vbe_info *info = (void*)(regs->di+0); + size_t info_size = offsetof(struct vbe_info, oem_data); if (GET_FARVAR(seg, info->signature) == VBE2_SIGNATURE) { dprintf(4, "Get VBE Controller: VBE2 Signature found\n"); + info_size = sizeof(*info); } else if (GET_FARVAR(seg, info->signature) == VESA_SIGNATURE) { dprintf(4, "Get VBE Controller: VESA Signature found\n"); } else { dprintf(4, "Get VBE Controller: Invalid Signature\n"); } - memset_far(seg, info, 0, sizeof(*info)); + memset_far(seg, info, 0, info_size); SET_FARVAR(seg, info->signature, VESA_SIGNATURE); |