From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 97E563A785C for ; Sun, 19 Jul 2026 15:43:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475835; cv=none; b=rDM+4D+oV8Zp1Ehu8QtDWIPnsgbX6u4VwmqMYSTjMypTf3+wqdsrB1xcuFUdfedm2UG17p3X8AW5foSKbyDQg2fblqMYPbfxOBhchYLKZFy2r9UJHBOjVHiFNFaXJP9aqjzegB8ceKFfkCJyDHQsRX+gS93f/uIhp4nRwmLcHMA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475835; c=relaxed/simple; bh=zbA5I1ltGu9t1EAWIH2/2vEOH5OP2MfgR71qPRpX2Pc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LP37S3gNGuoS983zCjivJMTJMEeLpSEHZ2EOJQxBbiU3p3sDlOmtUSp4uFHfY9Py0YQwqy4fcdudP6STL+fM2oAL6drP7/+SXajAHHk0ssO3aHMnrRbHcMiwgeY7+cTmueVHX6yay/GJG9YfcowU1Uus4JSSVO6I2X2hMTLvJl0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=x5mVJtYn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="x5mVJtYn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 030181F000E9; Sun, 19 Jul 2026 15:43:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475834; bh=rI+DSrpdcFnZmjH0hFARb2WmL4SCuEAPCMMcbJrFaX8=; h=From:To:Cc:Subject:Date:Reply-To; b=x5mVJtYnw51lwd8UB+Up0haUn3hjdmbV9rRpldG6J26mQ2N9s1ybbeczxLSKwZi4O L1LTb4VwFcMJ3TGHU4oY7rkOpk/3u9f4WKtFRnI+teW9LgJPREGPtEP4RqIThIqghc irDXNeX+Bzhss2SP+UAdKvXVOvnvgHNE7bTYJTfA= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64102: RDMA/siw: Reject MPA FPDU length underflow before signed receive math Date: Sun, 19 Jul 2026 17:39:24 +0200 Message-ID: <2026071920-CVE-2026-64102-dcb6@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5575; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=JYMQZzHvOhn3GhHKhKKfhXHoAyCpe4jMqXc9L/wmBnk=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx73P8/iis/7L9zM53JzcrRn6KiONMuJu5+KzbvvMdq UYT3+Rc64hlYRBkYpAVU2T5so3n6P6KQ4pehranYeawMoEMYeDiFICJBHEyzHdnl/GseN7re3uq 8/9be7d0+LVsC2BY0Pj1vddTV+Op/2Yd9+94Y1jGfCU9CwA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Reject MPA FPDU length underflow before signed receive math A malicious connected siw peer can send an iWARP FPDU whose MPA length field (c_hdr->mpa_len, 16 bit big-endian, peer-controlled) is smaller than the fixed DDP/RDMAP header for the announced opcode. Soft-iWARP parses the full header in siw_get_hdr() based on iwarp_pktinfo[opcode] .hdr_len, but never compares mpa_len against that header length. siw_tcp_rx_data() then derives srx->fpdu_part_rem = be16_to_cpu(mpa_len) - fpdu_part_rcvd + MPA_HDR_SIZE; where fpdu_part_rcvd equals iwarp_pktinfo[opcode].hdr_len at this point. For a tagged WRITE (hdr_len 16, MPA_HDR_SIZE 2) the smallest on-wire mpa_len of 0 yields fpdu_part_rem = -14, and any mpa_len below hdr_len - MPA_HDR_SIZE underflows to a negative int. The signed value then flows into siw_proc_write()/siw_proc_rresp() as bytes = min(srx->fpdu_part_rem, srx->skb_new); is handed to siw_check_mem() as an int len (whose interval check addr + len > mem->va + mem->len is satisfied for a valid base when len is negative), and reaches siw_rx_data() -> siw_rx_kva() / siw_rx_umem() -> skb_copy_bits() as a signed copy length. The header copy branch in skb_copy_bits() promotes that to size_t, producing a multi-gigabyte read. KASAN under a KUnit harness that drives the real kernel TCP receive path -- a loopback AF_INET socketpair, the malformed FPDU written via kernel_sendmsg, sk_data_ready firing in softirq, tcp_read_sock dispatching to siw_tcp_rx_data -- reports: BUG: KASAN: use-after-free in skb_copy_bits+0x284/0x480 Read of size 4294967295 at addr ffff888... Call Trace: skb_copy_bits siw_rx_kva siw_rx_data siw_check_mem siw_proc_write siw_tcp_rx_data __tcp_read_sock siw_qp_llp_data_ready tcp_data_ready tcp_data_queue Add the missing invariant at the earliest point where the peer header is fully assembled. iwarp_pktinfo[*].hdr_len - MPA_HDR_SIZE is exactly the value the siw transmitter uses as the minimum mpa_len for each opcode (drivers/infiniband/sw/siw/siw_qp.c:33), so this matches the protocol contract. Out-of-range FPDUs terminate the connection with TERM_ERROR_LAYER_LLP / LLP_ETYPE_MPA / LLP_ECODE_FPDU_START -- which is RFC 5044 Section 8 error code 3 ("Marker and ULPDU Length fields do not agree on the start of an FPDU"), the correct framing-error class for this inconsistency. The Linux kernel CVE team has assigned CVE-2026-64102 to this issue. Affected and fixed versions =========================== Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 5.10.258 with commit 683f7cfbf514193d63c0efa079f3352bde84c2e0 Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 5.15.209 with commit 4a331582011d9e8089af8aa2a61ec6b4443bb245 Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 6.1.175 with commit 33a8b5e971e294ec2a7b74211c545e09efd8e9ac Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 6.6.142 with commit 14553be882d9ce91749c9d64041de66e34ad8e70 Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 6.12.92 with commit c7c0c0f4379dedec12d24dbb9dded5d2db7fd9f2 Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 6.18.34 with commit 1012896f4225e8f801ff3c1648023845b66dfb11 Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 7.0.11 with commit 775b4dc9618a99a1fa48b57554041a5dc17e1336 Issue introduced in 5.3 with commit 8b6a361b8c482f22ac99c3273285ff16b23fba91 and fixed in 7.1 with commit 0ce1bc9e46ecabe84772bb561e373c0d9876d6f2 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-64102 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: drivers/infiniband/sw/siw/siw_qp_rx.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/683f7cfbf514193d63c0efa079f3352bde84c2e0 https://git.kernel.org/stable/c/4a331582011d9e8089af8aa2a61ec6b4443bb245 https://git.kernel.org/stable/c/33a8b5e971e294ec2a7b74211c545e09efd8e9ac https://git.kernel.org/stable/c/14553be882d9ce91749c9d64041de66e34ad8e70 https://git.kernel.org/stable/c/c7c0c0f4379dedec12d24dbb9dded5d2db7fd9f2 https://git.kernel.org/stable/c/1012896f4225e8f801ff3c1648023845b66dfb11 https://git.kernel.org/stable/c/775b4dc9618a99a1fa48b57554041a5dc17e1336 https://git.kernel.org/stable/c/0ce1bc9e46ecabe84772bb561e373c0d9876d6f2