From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793706602; b=xJkbHthCnm/gtru2dqlZUBsR1UMvHjliVf/vBuWEg4EkN7LQtAxV8JZuDz8csQ5FbW1z UscyLGOZP3mrmWh4/Wyb8hPAl4mGgl7SjKfDCEuS84g682Tb+vnWAyPhg9Lz3aj6y7URL rAb5HqjcKqhFdGdGBETIS3HBfq0298Gl10xkBF/kAjlfClTuM+8cIyszt2l4gI3ORmitv stfyL9P4xxYmw0V493/1MWzXmvPagHzEw3mhzwgHbmJngFnWspoGlPmnkIkaNQO3erHEM CujFApoEgRnoea6o4hFTY83VeJTqovK9rPyp89+gYL/s2NLbj0C77J9M3NDUeAyZEhA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793706602; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: Reply-To:MIME-Version:Lines:X-Developer-Signature:X-Developer-Key: Content-Transfer-Encoding; bh=sAjG/KJm+YhJYJcToiCtCS0RjbBST22hBMQ3fUKXA50=; b=3RvcFA1Oja+omcKnLVo5dXPMKOBjbOJqlHoOZDDXWFFG3YzvMRoF+xCoAZYi0EBfHuRg EgrIZmqTi/B/CU7IrnafhhUWh5YV1M3fVuAIUAkVPz0uc2M/pqIXH/F1hxJd357HLt9oS AK05PFGY1rSc31II4QjkHy/VVk81ntQ0wyxHusIGfWL4ccq+NAusx4rr6hgSmoBoNrke2 8XpgtZnxQCmpDHfb6HQcaW/LvViF3NnBy0+U1A7/2qYvA0yiJAlrHOJlGEq4rZoX6QDWx sJkTYx6d1bhtgwz8tfovdpYLEcZjVwFaDlscqFmB0x0tHECtfrUKfMBlmiTogK/LZZg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=b+pS6udZ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A2CCD606D807 for ; Tue, 3 Nov 2026 11:50:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=b+pS6udZ Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD3F61F00A1C; Tue, 3 Nov 2026 11:50:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793706601; bh=sAjG/KJm+YhJYJcToiCtCS0RjbBST22hBMQ3fUKXA50=; h=From:To:Cc:Subject:Date:Reply-To; b=b+pS6udZD356jE4Cog3fLfTStmLs4zOKsdpM/9XMW7zNMH2k2POWscWnkVm5wbx+C fquxo31/isllf4OP1j8t/ErkX1uDenIVoUVHKa7lZJy6Iob3hWVwJutNmF2P0kyG2d HTo8hXMzwuH9DMny/Z72eGEO92z7m2BJJ2oNUy/o= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-99263: io_uring/poll: avoid retry wakeup loss when dropping ownership Date: Tue, 3 Nov 2026 12:48:23 +0100 Message-ID: <2026110324-CVE-2026-99263-a07e@gregkh> X-Mailer: git-send-email 2.56.0 Reply-To: , X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3286; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=tIYDjUeNYmztT0nkNEi8M80SjS8WymkWkhBkzIiJo3s=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkvT3Gw2m3sPRWgazQ5Zqrh0oPuTVf5njC6By+XCSrwK No7y+VLRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEyEr5xhwabuDVOtn5iynZLI VWks3PP1Zq+1PcOCpod/9nw/dq7aQD5y77dpay6HT+z4BQA= 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/poll: avoid retry wakeup loss when dropping ownership If a wakeup sets IO_POLL_RETRY_FLAG between the owning task consuming the existing instance of IO_POLL_RETRY_FLAG and the loop check of io_poll_check_events(), then we stall on processing the request until an unrelated wakeup comes along. Using atomic_cmpxchg instead of atomic_sub_return to guarantee both the count v and poll_refs are 0 and no wake-ups are missed. The Linux kernel CVE team has assigned CVE-2026-99263 to this issue. Affected and fixed versions =========================== Issue introduced in 6.1 with commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea and fixed in 6.1.191 with commit d1f6850086ac6f8b0fa44fb19aa2a468c73ee071 Issue introduced in 6.1 with commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea and fixed in 6.6.161 with commit 41fae2e9e1fa3bee86aee0a25ba90e59ce5024bf Issue introduced in 6.1 with commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea and fixed in 6.12.115 with commit 4ef685b8505615729d75c875f52822238bf76ca6 Issue introduced in 6.1 with commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea and fixed in 6.18.60 with commit afa407c02f3aa0fd872f86c9bf1b34502e0fa8f0 Issue introduced in 6.1 with commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea and fixed in 7.2.14 with commit eb2a50d8235e4580fea9aa20f3fbe1a002c38cb1 Issue introduced in 6.1 with commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea and fixed in 7.3.1 with commit 521e8a65e9b45532295ba1082ef12be6e80c173b Issue introduced in 5.15.82 with commit 4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048 Issue introduced in 6.0.11 with commit bc4e6ee16778149811333a969a7a893d4cc110c5 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-2026-99263 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/poll.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/d1f6850086ac6f8b0fa44fb19aa2a468c73ee071 https://git.kernel.org/stable/c/41fae2e9e1fa3bee86aee0a25ba90e59ce5024bf https://git.kernel.org/stable/c/4ef685b8505615729d75c875f52822238bf76ca6 https://git.kernel.org/stable/c/afa407c02f3aa0fd872f86c9bf1b34502e0fa8f0 https://git.kernel.org/stable/c/eb2a50d8235e4580fea9aa20f3fbe1a002c38cb1 https://git.kernel.org/stable/c/521e8a65e9b45532295ba1082ef12be6e80c173b https://git.kernel.org/stable/c/937d38dcacd675dc0572d6c9b6743960df3128ed