{"id":2222960,"url":"http://patchwork.ozlabs.org/api/patches/2222960/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260414141458.1076014-1-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":"<20260414141458.1076014-1-junjie.cao@intel.com>","list_archive_url":null,"date":"2026-04-14T14:14:58","name":"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/20260414141458.1076014-1-junjie.cao@intel.com/mbox/","series":[{"id":499779,"url":"http://patchwork.ozlabs.org/api/series/499779/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=499779","date":"2026-04-14T14:14:58","name":"ati-vga: fix unsigned integer overflow in cursor bounds checks","version":1,"mbox":"http://patchwork.ozlabs.org/series/499779/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2222960/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2222960/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=KN2ulJ7j;\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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13 Apr 2026 23:12:01 -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=1776147127; x=1807683127;\n h=from:to:cc:subject:date:message-id:mime-version:\n content-transfer-encoding;\n bh=3XvAI5ocW9PBGVckY0gOKaJpApfDZp5w06MPw8ikhDA=;\n b=KN2ulJ7j1qNNUlV/P7dVtrZfrJelYmYm5smUOh7nSZpOnlINphjY1NRG\n 1pqiYKsW4Iz0UeWSxkQxHFP3cGm1XGWjdguBfI3FcbyFyE4eQppZO01gW\n i436zGX2OpMf2fCd0KDpiz0qFVjEJkLxj6IhAUdqvUINX6R2/q492W2m+\n BJdyfKC25KzEy67+kaFjDnxK58CZrh/8qhll6edSujDokXCeMn1hV9ifZ\n GX8xhPZxy9H/orviVhoAwBiAqkJrJp2J95HHk9YKIkr66I0cy6gu7LUkO\n 8l3r6+VXVilGTM4ruSERvhkLtFZwrS919LYJewcGFwg+da4kQ63Q+AZC7 w==;","X-CSE-ConnectionGUID":["FHVjNO7jQr+7V65OybofjA==","SzLqRB7ZQK2UJLXtHiG/hg=="],"X-CSE-MsgGUID":["cOXI+AcVRvqXCd2gU6qW1g==","6wWTaxqJSPSFvYs9baRHVQ=="],"X-IronPort-AV":["E=McAfee;i=\"6800,10657,11758\"; a=\"76125915\"","E=Sophos;i=\"6.23,179,1770624000\"; d=\"scan'208\";a=\"76125915\"","E=Sophos;i=\"6.23,179,1770624000\"; d=\"scan'208\";a=\"231729218\""],"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?= , junjie.cao@intel.com,\n qemu-stable@nongnu.org","Subject":"[PATCH] ati-vga: fix unsigned integer overflow in cursor bounds\n checks","Date":"Tue, 14 Apr 2026 22:14:58 +0800","Message-ID":"<20260414141458.1076014-1-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=192.198.163.19;\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 \n---\nFound while running local QEMU fuzz testing.\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":[]}