{"id":2223115,"url":"http://patchwork.ozlabs.org/api/patches/2223115/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260414213523.1125859-1-junjie.cao@intel.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260414213523.1125859-1-junjie.cao@intel.com>","list_archive_url":null,"date":"2026-04-14T21:35:22","name":"[v2,1/2] ati-vga: fix unsigned integer overflow in cursor bounds checks","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"cddd3feba53abe88b4ad029eb6946793d549d038","submitter":{"id":91537,"url":"http://patchwork.ozlabs.org/api/people/91537/?format=json","name":"Junjie Cao","email":"junjie.cao@intel.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260414213523.1125859-1-junjie.cao@intel.com/mbox/","series":[{"id":499846,"url":"http://patchwork.ozlabs.org/api/series/499846/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=499846","date":"2026-04-14T21:35:22","name":"[v2,1/2] ati-vga: fix unsigned integer overflow in cursor bounds checks","version":2,"mbox":"http://patchwork.ozlabs.org/series/499846/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2223115/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2223115/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256\n header.s=Intel header.b=OZD95Wm6;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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14 Apr 2026 06:32:32 -0700"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple;\n d=intel.com; i=@intel.com; q=dns/txt; s=Intel;\n t=1776173557; x=1807709557;\n h=from:to:cc:subject:date:message-id:mime-version:\n content-transfer-encoding;\n bh=aVLd6fAzNsrg8HssHvbjJoomKlJxcy2FIXt/dMBZIMo=;\n b=OZD95Wm6F9sO5RK8JmdvmPGCGY/ajpq3F2ZGZzq9vulTxWSsE1YJ3wji\n 3rKMa6D6iMnM4ft8m2XrcL8je5EFzpeHa7u2eW9O2trRuD7xRo+KCCNkX\n HxFo3r/gJSAbTkaiYdC5idEE3IIIJn+rwaIZRq7hioNBetj2xPGcxJlek\n tdoz7N6bwgL06KubhHryRAJTiEplM7j8BuDdkJWfbkB93OH9bSjdOb1/K\n JneW+1gkP63OfBSVcpdRpU63ivH0wUTUbUGrEsLq87bdNBpcqavtv7zcA\n RfkvTDcKLbM5Dibi++u6AKAX4VFsuz1JCoVWTmJOq24YzrC8LvvFm9Q94 g==;","X-CSE-ConnectionGUID":["9rOChN1+QaWfsgKmftp6zA==","Ko4ALbkaSQiHtRTIZ07LZg=="],"X-CSE-MsgGUID":["zAd5NtvpRDalFICQsL+3Jw==","tLsSbyNbT3m6529gryJCOQ=="],"X-IronPort-AV":["E=McAfee;i=\"6800,10657,11759\"; a=\"77201411\"","E=Sophos;i=\"6.23,179,1770624000\"; d=\"scan'208\";a=\"77201411\"","E=Sophos;i=\"6.23,179,1770624000\"; d=\"scan'208\";a=\"227447816\""],"X-ExtLoop1":"1","From":"Junjie Cao ","To":"qemu-devel@nongnu.org","Cc":"BALATON Zoltan , =?utf-8?q?Philippe_Mathieu-Daud?=\n\t=?utf-8?q?=C3=A9?= , Chad Jablonski ,\n qemu-stable@nongnu.org, junjie.cao@intel.com","Subject":"[PATCH v2 1/2] ati-vga: fix unsigned integer overflow in cursor\n bounds checks","Date":"Wed, 15 Apr 2026 05:35:22 +0800","Message-ID":"<20260414213523.1125859-1-junjie.cao@intel.com>","X-Mailer":"git-send-email 2.43.0","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Received-SPF":"pass client-ip=192.198.163.14;\n envelope-from=junjie.cao@intel.com;\n helo=mgamail.intel.com","X-Spam_score_int":"-29","X-Spam_score":"-3.0","X-Spam_bar":"---","X-Spam_report":"(-3.0 / 5.0 requ) BAYES_00=-1.9, DATE_IN_FUTURE_06_12=1.947,\n DKIMWL_WL_HIGH=-0.54, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1,\n DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"The cursor bounds checks compare (srcoff + N) against vram_size, but\nboth sides are uint32_t so the addition can wrap past UINT32_MAX when\nsrcoff underflows from the cur_hv_offs subtraction, causing the check\nto be bypassed.\n\nRewrite the checks as (srcoff > vram_size - N) to avoid the\noverflow-prone addition, matching the style already used in\nati_mm_read() and ati_mm_write().\n\nFixes: 2f1fbe6ee9b5 (\"ati-vga: Make sure hardware cursor data is within vram\")\nCc: qemu-stable@nongnu.org\nSigned-off-by: Junjie Cao \nReviewed-by: BALATON Zoltan \n---\nFound while running local QEMU fuzz testing.\n\nv2: Collected Reviewed-by, added patch 2/2 to mask out the lock bit\n as suggested by BALATON Zoltan.\n\n hw/display/ati.c | 4 ++--\n 1 file changed, 2 insertions(+), 2 deletions(-)","diff":"diff --git a/hw/display/ati.c b/hw/display/ati.c\nindex 88a5bbbf07..0489995d00 100644\n--- a/hw/display/ati.c\n+++ b/hw/display/ati.c\n@@ -149,7 +149,7 @@ static void ati_cursor_define(ATIVGAState *s)\n /* FIXME handle cur_hv_offs correctly */\n srcoff = s->regs.cur_offset - (s->regs.cur_hv_offs >> 16) -\n (s->regs.cur_hv_offs & 0xffff) * 16;\n- if (srcoff + 64 * 16 > s->vga.vram_size) {\n+ if (srcoff > s->vga.vram_size - 64 * 16) {\n return;\n }\n for (int i = 0; i < 64; i++, srcoff += 16) {\n@@ -206,7 +206,7 @@ static void ati_cursor_draw_line(VGACommonState *vga, uint8_t *d, int scr_y)\n }\n /* FIXME handle cur_hv_offs correctly */\n srcoff = s->cursor_offset + (scr_y - vga->hw_cursor_y) * 16;\n- if (srcoff + 16 > s->vga.vram_size) {\n+ if (srcoff > s->vga.vram_size - 16) {\n return;\n }\n dp = &dp[vga->hw_cursor_x];\n","prefixes":["v2","1/2"]}