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([14.22.11.167]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-8480da8bab0sm12070765b3a.8.2026.07.13.00.23.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2026 00:24:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783927441; x=1784532241; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=U377PjbcCXoZWc+3EuDN1mi9AZSmdy6wOFV7gOgTSkQ=; b=eEejI7S3VLNT34CxurmMSGgZ4R8O/jpghZX8G3NfvC1eB3HK2dbgrfIRBJWhtXzP7h xl8ZkBA4zYtsoLQnJZpVYK3gfqw3Bx9mfr2i1bAh9VJHg8ng68DA26CjT21acuHpCP/i VG1g7SVpbKIHGWTP1KOIV9Q/XgY6WM6QCSm3rJz9V0rRijGxbYi7I0tAXVjecRldlbxf /5svYjPWF/Amlj0f109uUhToi6cxpffKJX3w/QbsrvMLgU4lfHVh/kWYgpSTf0UU1ATS YH7itm2WQldW7IuGkE2w2/KhUzg6eXClTTBGjGCbMuFLHh8kEybgULKGLE0Zwr4YrbBm XNbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783927441; x=1784532241; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=U377PjbcCXoZWc+3EuDN1mi9AZSmdy6wOFV7gOgTSkQ=; b=UvJkgSiQYNPIs3BI3rzZ07HzuK24yAXqyPn1nyKfy0VmNVtx7IxK8DB++keSs/oKnM pHjQtCD5Ng64XBKhxPzUShANQKRMlncVPp+5JtsgId94IwltECT7n90k/PSnY9bCR4T+ 2vD8gKRiX9H1LrtH41FBnV6uSyeAtdwDfQlaJhambI94P26w1biNBAR+ukjnajbV8yvI NwNgBBlj7nyYM8wUUGaTryOYANe8x2YYK/6sgO+7h24k/KOk+rCSpCa36xbHugj5A83y aN8m7eGkGXBVgffgW+JWx6hsNiqcZLscrE8RGZ6x6sKkFwwjN1gxkpsIgqrFfSgWClg3 +ptA== X-Gm-Message-State: AOJu0Yxz89xiwBCrg8UwTJxfnK+B3Ck1MtQs5z0KXnsQvx6vfcWT3dgC /+0h4jZGX9n43Z01hogO/kJx3OxvYYhXHckCJZM5PHa0/T7WPWSfR0qnY9KK/qzfpntJZ/B0CPs = X-Gm-Gg: AfdE7ckbVtgKw+xMB1DVt2xcXdDaNmOyzlRi4QiwFnqNlBPNx7+BEI97aPGNOSSTc+g syzIIaJB9Hc/LIzbzYNkgjHjbAR9zzDOUe0NjHUHG3QFRc/jAlcHHcW0hhKFNxVzLLXo94WDCb4 xKCKdmzn48C+Oyth+DfOrtR4YVIvxo+FhT3UfjXDME/FQ5qTCk9Z9WAiJG0sCn8JISOqcrSiHnn zRh3veHq2qD/tRjO7Qe+Ss/ngmvqO3lk0a5acx96pmU1JXzy/VwAeKCvjoNAtfTXSETDSHQ1pmc ntLUoIRcrbU5bz6HEq5ZsOGOOnnPaLovzdE2+BsStVQbsbC7dbWCu/6ada1PwfxCl+/domqXnaM jGk+j4slEXfsMLpZRP4d3Msgiy9Ro62p6uH6JSG1Z1WsmgvOXqaqyf4Gq7HCo7EDt0ppfNrp+gk hXP5EXoyWthz/nmrymo/unARpYfrBEHS+ISkgji/YlzYc+X4cHJPBBQX40T1XEx6Hisgaz+ebEq Z4HC3MMU5ck6asBPm9WsLyv+D4yEfpdWaerpTA= X-Received: by 2002:a05:6a00:a117:b0:848:824d:aff4 with SMTP id d2e1a72fcca58-848896fee6fmr6810738b3a.56.1783927440952; Mon, 13 Jul 2026 00:24:00 -0700 (PDT) From: jianghaotian.sunday@gmail.com To: qemu-devel@nongnu.org Cc: jic23@kernel.org, mst@redhat.com, linux-cxl@vger.kernel.org, qemu-stable@nongnu.org, Haotian Jiang Subject: [PATCH 1/1] hw/cxl: fix OOB access in cxl_doe_cdat_rsp via entry_handle Date: Mon, 13 Jul 2026 15:23:36 +0800 Message-Id: <20260713072336.623604-2-jianghaotian.sunday@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260713072336.623604-1-jianghaotian.sunday@gmail.com> References: <20260713072336.623604-1-jianghaotian.sunday@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists1p.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:3b::1; envelope-from=jianghaotian.sunday@gmail.com; helo=mail-pz2-x01.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Mon, 13 Jul 2026 08:39:04 -0400 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @gmail.com) X-ZM-MESSAGEID: 1783946381689158500 Content-Type: text/plain; charset="utf-8" From: Haotian Jiang cxl_doe_cdat_rsp() takes ent =3D req->entry_handle (uint16_t, fully guest-controlled, 0..0xFFFF) and directly indexes cdat->entry[ent] without checking ent < cdat->entry_len. For a default cxl-type3 with one volatile memory region, entry_len =3D 1 + CT3_CDAT_NUM_ENTRIES =3D 7, so any entry_handle >=3D 7 reads past the CDATEntry array into host heap. The OOB-read base/length are then used in memcpy(read_mbox + offset, base, len) at cxl_type3.c:298-299, leaking host heap memory to the guest via PCI_EXP_DOE_RD_DATA_MBOX, and potentially overflowing the 1 MiB read_mbox heap buffer when the OOB length field is large. The same bug exists in the cxl-upstream implementation. Existing checks do not bound ent: assert(cdat->entry_len) only ensures the table is loaded; the minimum-length check only guards against a truncated CDATReq; the entry_handle ternary at line 293 only decides the next-handle echo, not the current access; pcie_doe_get_obj_len reads header.length, not entry_handle. Reproduce: build QEMU with CONFIG_CXL, boot -M q35,cxl=3Don -device pxb-cxl,bus_nr=3D52 ... -device cxl-type3,... then send a CDATReq with entry_handle=3D0xFFFF via the DOE mailbox at config offset 0x190. Under ASAN this reports SEGV in cxl_doe_cdat_rsp at cxl_type3.c:281. Fixes: f5ee7413d5 ("hw/mem/cxl-type3: Add CXL CDAT Data Object Exchange") Fixes: 882877fc35 ("hw/pci-bridge/cxl-upstream: Add a CDAT table access DOE= ") Signed-off-by: Haotian Jiang Cc: qemu-stable@nongnu.org Reviewed-by: Jonathan Cameron --- hw/mem/cxl_type3.c | 3 +++ hw/pci-bridge/cxl_upstream.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c index cba05ec57d..28f41fa623 100644 --- a/hw/mem/cxl_type3.c +++ b/hw/mem/cxl_type3.c @@ -278,6 +278,9 @@ static bool cxl_doe_cdat_rsp(DOECap *doe_cap) } =20 ent =3D req->entry_handle; + if (ent >=3D cdat->entry_len) { + return false; + } base =3D cdat->entry[ent].base; len =3D cdat->entry[ent].length; =20 diff --git a/hw/pci-bridge/cxl_upstream.c b/hw/pci-bridge/cxl_upstream.c index b6281cbd4c..69773ff163 100644 --- a/hw/pci-bridge/cxl_upstream.c +++ b/hw/pci-bridge/cxl_upstream.c @@ -158,6 +158,9 @@ static bool cxl_doe_cdat_rsp(DOECap *doe_cap) } =20 ent =3D req->entry_handle; + if (ent >=3D cdat->entry_len) { + return false; + } base =3D cdat->entry[ent].base; len =3D cdat->entry[ent].length; =20 --=20 2.34.1