diff options
| author | Zack Rusin <zack.rusin@broadcom.com> | 2026-05-05 18:22:27 -0400 |
|---|---|---|
| committer | Zack Rusin <zack.rusin@broadcom.com> | 2026-07-27 11:29:24 -0400 |
| commit | 85891d174707d8bddcec7a888fb4e1d17def34f3 (patch) | |
| tree | c7e61ab1c16768ce0d3b5bc6a13e94c2c4588322 /drivers/gpu/drm | |
| parent | f739416dc555fa205a785e5135d73fa39b26f35d (diff) | |
drm/vmwgfx: validate DRAW_PRIMITIVES header size before division
vmw_cmd_draw() computes
maxnum = (header->size - sizeof(cmd->body)) / sizeof(*decl);
where header->size is u32 and is taken straight from the user-supplied
command stream. When header->size is less than sizeof(cmd->body) the
unsigned subtraction wraps to nearly 4 GiB, producing a huge maxnum.
Any user-controlled cmd->body.numVertexDecls then passes the bound and
the loop dereferences decl[i] far past the end of the kernel command
bounce buffer, producing an out-of-bounds read of kernel memory.
Reject undersized headers up front.
Fixes: 7a73ba7469cb ("drm/vmwgfx: Use TTM handles instead of SIDs as user-space surface handles.")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4.7
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Reviewed-by: Ian Forbes <ian.forbes@broadcom.com>
Link: https://patch.msgid.link/20260505222728.519626-7-zack.rusin@broadcom.com
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c index b07f052474d0..2410d53a75aa 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c @@ -1571,11 +1571,17 @@ static int vmw_cmd_draw(struct vmw_private *dev_priv, uint32_t maxnum; int ret; + cmd = container_of(header, typeof(*cmd), header); + + if (unlikely(header->size < sizeof(cmd->body))) { + VMW_DEBUG_USER("Illegal DRAW_PRIMITIVES header size.\n"); + return -EINVAL; + } + ret = vmw_cmd_cid_check(dev_priv, sw_context, header); if (unlikely(ret != 0)) return ret; - cmd = container_of(header, typeof(*cmd), header); maxnum = (header->size - sizeof(cmd->body)) / sizeof(*decl); if (unlikely(cmd->body.numVertexDecls > maxnum)) { |