This is a note to let you know that I've just added the patch titled
drm/vmwgfx: Fix a null-ptr access in the cursor snooper
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vmwgfx-fix-a-null-ptr-access-in-the-cursor-snooper.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From [email protected] Wed Dec 24 09:57:13
>2025
From: Shivani Agarwal <[email protected]>
Date: Wed, 24 Dec 2025 00:36:52 -0800
Subject: drm/vmwgfx: Fix a null-ptr access in the cursor snooper
To: [email protected], [email protected]
Cc: [email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected], [email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected],
[email protected], [email protected],
[email protected], [email protected], Kuzey Arda Bulut
<[email protected]>, Ian Forbes <[email protected]>, Sasha Levin
<[email protected]>, Shivani Agarwal <[email protected]>
Message-ID: <[email protected]>
From: Zack Rusin <[email protected]>
[ Upstream commit 5ac2c0279053a2c5265d46903432fb26ae2d0da2 ]
Check that the resource which is converted to a surface exists before
trying to use the cursor snooper on it.
vmw_cmd_res_check allows explicit invalid (SVGA3D_INVALID_ID) identifiers
because some svga commands accept SVGA3D_INVALID_ID to mean "no surface",
unfortunately functions that accept the actual surfaces as objects might
(and in case of the cursor snooper, do not) be able to handle null
objects. Make sure that we validate not only the identifier (via the
vmw_cmd_res_check) but also check that the actual resource exists before
trying to do something with it.
Fixes unchecked null-ptr reference in the snooping code.
Signed-off-by: Zack Rusin <[email protected]>
Fixes: c0951b797e7d ("drm/vmwgfx: Refactor resource management")
Reported-by: Kuzey Arda Bulut <[email protected]>
Cc: Broadcom internal kernel review list <[email protected]>
Cc: [email protected]
Reviewed-by: Ian Forbes <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
[Shivani: Modified to apply on v5.10.y-v6.1.y]
Signed-off-by: Shivani Agarwal <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -1507,6 +1507,7 @@ static int vmw_cmd_dma(struct vmw_privat
SVGA3dCmdHeader *header)
{
struct vmw_buffer_object *vmw_bo = NULL;
+ struct vmw_resource *res;
struct vmw_surface *srf = NULL;
VMW_DECLARE_CMD_VAR(*cmd, SVGA3dCmdSurfaceDMA);
int ret;
@@ -1542,18 +1543,24 @@ static int vmw_cmd_dma(struct vmw_privat
dirty = (cmd->body.transfer == SVGA3D_WRITE_HOST_VRAM) ?
VMW_RES_DIRTY_SET : 0;
- ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
- dirty, user_surface_converter,
- &cmd->body.host.sid, NULL);
+ ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface, dirty,
+ user_surface_converter, &cmd->body.host.sid,
+ NULL);
if (unlikely(ret != 0)) {
if (unlikely(ret != -ERESTARTSYS))
VMW_DEBUG_USER("could not find surface for DMA.\n");
return ret;
}
- srf = vmw_res_to_srf(sw_context->res_cache[vmw_res_surface].res);
+ res = sw_context->res_cache[vmw_res_surface].res;
+ if (!res) {
+ VMW_DEBUG_USER("Invalid DMA surface.\n");
+ return -EINVAL;
+ }
- vmw_kms_cursor_snoop(srf, sw_context->fp->tfile, &vmw_bo->base, header);
+ srf = vmw_res_to_srf(res);
+ vmw_kms_cursor_snoop(srf, sw_context->fp->tfile, &vmw_bo->base,
+ header);
return 0;
}
Patches currently in stable-queue which might be from
[email protected] are
queue-6.1/usb-xhci-move-link-chain-bit-quirk-checks-into-one-helper-function.patch
queue-6.1/crypto-af_alg-zero-initialize-memory-allocated-via-sock_kmalloc.patch
queue-6.1/rdma-core-fix-kasan-slab-use-after-free-read-in-ib_register_device-problem.patch
queue-6.1/drm-vmwgfx-fix-a-null-ptr-access-in-the-cursor-snooper.patch
queue-6.1/usb-xhci-apply-the-link-chain-quirk-on-nec-isoc-endpoints.patch
