From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2B53F1FB4F for ; Tue, 1 Aug 2023 09:39:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A34CDC433C8; Tue, 1 Aug 2023 09:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690882752; bh=62D2k3OGawUNgXwJFf9aU26h7s2z0ixNwbuJ/pXYUd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RUgMcA9bSNkZnJLrIdNoDShHZrmE9BjVvHmQjvRQ+RIedY8tj56Srl27iBdtyUdIQ Bbl7N1IpQ9G/L/wrjbQD5XoQVOQ9SquHEmaoYeBadpt+jQt+nxogpamajMmntK3g+e t/W2RtOOEHLvshowuSC/jphr6Mcz11+Gha/L17dg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Leo Li , Hamza Mahfooz , Alex Deucher Subject: [PATCH 6.1 219/228] drm/amd/display: perform a bounds check before filling dirty rectangles Date: Tue, 1 Aug 2023 11:21:17 +0200 Message-ID: <20230801091930.763567068@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230801091922.799813980@linuxfoundation.org> References: <20230801091922.799813980@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Hamza Mahfooz commit af22d6a869cc26b519bfdcd54293c53f2e491870 upstream. Currently, it is possible for us to access memory that we shouldn't. Since, we acquire (possibly dangling) pointers to dirty rectangles before doing a bounds check to make sure we can actually accommodate the number of dirty rectangles userspace has requested to fill. This issue is especially evident if a compositor requests both MPO and damage clips at the same time, in which case I have observed a soft-hang. So, to avoid this issue, perform the bounds check before filling a single dirty rectangle and WARN() about it, if it is ever attempted in fill_dc_dirty_rect(). Cc: stable@vger.kernel.org # 6.1+ Fixes: 30ebe41582d1 ("drm/amd/display: add FB_DAMAGE_CLIPS support") Reviewed-by: Leo Li Signed-off-by: Hamza Mahfooz Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4953,11 +4953,7 @@ static inline void fill_dc_dirty_rect(st int32_t y, int32_t width, int32_t height, int *i, bool ffu) { - if (*i > DC_MAX_DIRTY_RECTS) - return; - - if (*i == DC_MAX_DIRTY_RECTS) - goto out; + WARN_ON(*i >= DC_MAX_DIRTY_RECTS); dirty_rect->x = x; dirty_rect->y = y; @@ -4973,7 +4969,6 @@ static inline void fill_dc_dirty_rect(st "[PLANE:%d] PSR SU dirty rect at (%d, %d) size (%d, %d)", plane->base.id, x, y, width, height); -out: (*i)++; } @@ -5055,6 +5050,9 @@ static void fill_dc_dirty_rects(struct d new_plane_state->plane->base.id, bb_changed, fb_changed, num_clips); + if ((num_clips + (bb_changed ? 2 : 0)) > DC_MAX_DIRTY_RECTS) + goto ffu; + if (bb_changed) { fill_dc_dirty_rect(new_plane_state->plane, &dirty_rects[i], new_plane_state->crtc_x, @@ -5084,9 +5082,6 @@ static void fill_dc_dirty_rects(struct d new_plane_state->crtc_h, &i, false); } - if (i > DC_MAX_DIRTY_RECTS) - goto ffu; - flip_addrs->dirty_rect_count = i; return;