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 E18F43C942C for ; Fri, 1 May 2026 14:20:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777645247; cv=none; b=YJW731YzGLaRjH1uXpSiMW6TE/vwCaKuZapZ4/WSx43keGXXAOk6sP8CnvZYfBLN/cD1cfCxjFtT7cMu3r3tuf7IXYA3ZGUAQ6LeY1n+iusVo6fZAlhgDTcSgttPkSjmW0EAzAcXUNbfg270JyOP/Ach+oRl9Vi3zD0E2ojE4hc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777645247; c=relaxed/simple; bh=DsOW0IQ/c8Jawald4+2MegHzP1VmdTOLrHgfbvJJNdY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HawO23ztzEHJrhH3gmFjKGTI+vI+8CRDqdm8ZZ3gzhFDXjTIWkuG1kL/G16zW3U5KLf1dBBEu6KVFNvZmCc8G8YccQcfQ5N1xHtSOdAVY08pDTkoHpILZrbhj+g1dghJ8suA81dm9LbGwngvL036g/uBl1HCCJwPzPq8iM6dOmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qyIZibZn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qyIZibZn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 731DDC2BCB4; Fri, 1 May 2026 14:20:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777645246; bh=DsOW0IQ/c8Jawald4+2MegHzP1VmdTOLrHgfbvJJNdY=; h=From:To:Cc:Subject:Date:Reply-To:From; b=qyIZibZnLt7ehUlMD4RTNgPzPQWAjZvDYiEbc1DaEuJF3eHDY+uMVAn8NqWzRY4vv XALLhjivA0UJnceN2Ke38GXMFdd6m6VR+V9wB9diWKPTnQ1DWn4WNQUjjnxOzG/js+ +vlolYQwkv5dbMGpxtNustOd5Fm+HzIG3dbVF/ew= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-43006: io_uring/rsrc: reject zero-length fixed buffer import Date: Fri, 1 May 2026 16:15:39 +0200 Message-ID: <2026050153-CVE-2026-43006-e4be@gregkh> X-Mailer: git-send-email 2.54.0 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=2974; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=TStmzpbypS4Y0taJQrFWf84OI7x6tHyrordwSk0LbJE=; b=owGbwMvMwCRo6H6F97bub03G02pJDJlftsZ6Fmuc2F2Z8SVP657UpGnrMt8ZPxXonPvPoIvT8 OlcprVfOmJZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAi888zzC+SWl7e0FrhJOau t3NDncI9tuUiygwL+nliNF45+V7hf2pQ7rm06OzCBoNaAA== 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: io_uring/rsrc: reject zero-length fixed buffer import validate_fixed_range() admits buf_addr at the exact end of the registered region when len is zero, because the check uses strict greater-than (buf_end > imu->ubuf + imu->len). io_import_fixed() then computes offset == imu->len, which causes the bvec skip logic to advance past the last bio_vec entry and read bv_offset from out-of-bounds slab memory. Return early from io_import_fixed() when len is zero. A zero-length import has no data to transfer and should not walk the bvec array at all. BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0 Read of size 4 at addr ffff888002bcc254 by task poc/103 Call Trace: io_import_reg_buf+0x697/0x7f0 io_write_fixed+0xd9/0x250 __io_issue_sqe+0xad/0x710 io_issue_sqe+0x7d/0x1100 io_submit_sqes+0x86a/0x23c0 __do_sys_io_uring_enter+0xa98/0x1590 Allocated by task 103: The buggy address is located 12 bytes to the right of allocated 584-byte region [ffff888002bcc000, ffff888002bcc248) The Linux kernel CVE team has assigned CVE-2026-43006 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit 8622b20f23ed165f48b8ca61503a107d17f8d585 and fixed in 6.18.22 with commit 040a1e7e0e2f01851fec1dd2d96906f8636a9f75 Issue introduced in 6.15 with commit 8622b20f23ed165f48b8ca61503a107d17f8d585 and fixed in 6.19.12 with commit 40170fc1a79c1b2e68f09ae6aac687b7305ae6f4 Issue introduced in 6.15 with commit 8622b20f23ed165f48b8ca61503a107d17f8d585 and fixed in 7.0 with commit 111a12b422a8cfa93deabaef26fec48237163214 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-2026-43006 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: io_uring/rsrc.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/040a1e7e0e2f01851fec1dd2d96906f8636a9f75 https://git.kernel.org/stable/c/40170fc1a79c1b2e68f09ae6aac687b7305ae6f4 https://git.kernel.org/stable/c/111a12b422a8cfa93deabaef26fec48237163214