From: Zack Rusin <zack.rusin@broadcom.com> stable inclusion from stable-v5.10.215 commit c560327d900bab968c2e1b4cd7fa2d46cd429e3d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9L4RT CVE: CVE-2024-26979 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 517621b7060096e48e42f545fa6646fc00252eac ] vmw_context_cotable can return either an error or a null pointer and its usage sometimes went unchecked. Subsequent code would then try to access either a null pointer or an error value. The invalid dereferences were only possible with malformed userspace apps which never properly initialized the rendering contexts. Check the results of vmw_context_cotable to fix the invalid derefs. Thanks: ziming zhang(@ezrak1e) from Ant Group Light-Year Security Lab who was the first person to discover it. Niels De Graef who reported it and helped to track down the poc. Fixes: 9c079b8ce8bf ("drm/vmwgfx: Adapt execbuf to the new validation api") Cc: <stable@vger.kernel.org> # v4.20+ Reported-by: Niels De Graef <ndegraef@redhat.com> Signed-off-by: Zack Rusin <zack.rusin@broadcom.com> Cc: Martin Krastev <martin.krastev@broadcom.com> Cc: Maaz Mombasawala <maaz.mombasawala@broadcom.com> Cc: Ian Forbes <ian.forbes@broadcom.com> Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com> Cc: dri-devel@lists.freedesktop.org Reviewed-by: Maaz Mombasawala <maaz.mombasawala@broadcom.com> Reviewed-by: Martin Krastev <martin.krastev@broadcom.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240110200305.94086-1-zack.ru... Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Pu Lehui <pulehui@huawei.com> --- drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c index 831291b5d1a0..616f6cb62278 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c @@ -467,7 +467,7 @@ static int vmw_resource_context_res_add(struct vmw_private *dev_priv, vmw_res_type(ctx) == vmw_res_dx_context) { for (i = 0; i < cotable_max; ++i) { res = vmw_context_cotable(ctx, i); - if (IS_ERR(res)) + if (IS_ERR_OR_NULL(res)) continue; ret = vmw_execbuf_res_noctx_val_add(sw_context, res, @@ -1272,6 +1272,8 @@ static int vmw_cmd_dx_define_query(struct vmw_private *dev_priv, return -EINVAL; cotable_res = vmw_context_cotable(ctx_node->ctx, SVGA_COTABLE_DXQUERY); + if (IS_ERR_OR_NULL(cotable_res)) + return cotable_res ? PTR_ERR(cotable_res) : -EINVAL; ret = vmw_cotable_notify(cotable_res, cmd->body.queryId); return ret; @@ -2450,6 +2452,8 @@ static int vmw_cmd_dx_view_define(struct vmw_private *dev_priv, return ret; res = vmw_context_cotable(ctx_node->ctx, vmw_view_cotables[view_type]); + if (IS_ERR_OR_NULL(res)) + return res ? PTR_ERR(res) : -EINVAL; ret = vmw_cotable_notify(res, cmd->defined_id); if (unlikely(ret != 0)) return ret; @@ -2535,8 +2539,8 @@ static int vmw_cmd_dx_so_define(struct vmw_private *dev_priv, so_type = vmw_so_cmd_to_type(header->id); res = vmw_context_cotable(ctx_node->ctx, vmw_so_cotables[so_type]); - if (IS_ERR(res)) - return PTR_ERR(res); + if (IS_ERR_OR_NULL(res)) + return res ? PTR_ERR(res) : -EINVAL; cmd = container_of(header, typeof(*cmd), header); ret = vmw_cotable_notify(res, cmd->defined_id); @@ -2655,6 +2659,8 @@ static int vmw_cmd_dx_define_shader(struct vmw_private *dev_priv, return -EINVAL; res = vmw_context_cotable(ctx_node->ctx, SVGA_COTABLE_DXSHADER); + if (IS_ERR_OR_NULL(res)) + return res ? PTR_ERR(res) : -EINVAL; ret = vmw_cotable_notify(res, cmd->body.shaderId); if (ret) return ret; @@ -2976,6 +2982,8 @@ static int vmw_cmd_dx_define_streamoutput(struct vmw_private *dev_priv, } res = vmw_context_cotable(ctx_node->ctx, SVGA_COTABLE_STREAMOUTPUT); + if (IS_ERR_OR_NULL(res)) + return res ? PTR_ERR(res) : -EINVAL; ret = vmw_cotable_notify(res, cmd->body.soid); if (ret) return ret; -- 2.34.1