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 08A2C4ACC81 for ; Fri, 4 Sep 2026 15:59:07 +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=1788537550; cv=none; b=SdBveI9o7zZE6JUlmgjm565BOKG2hyNQVfafx7EWmbxhESxATWjUsHbjzdsglJPWGuwFNl02TGYDQxYZ+yuvifsR3x6dgggvtkrNpTfXfSTnSzkA7J9+g9sGUw6nY3whqPZn2Ju8+FuWwwGHFHVqW/A/zhuTB+a+f9qRojdUvRQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788537550; c=relaxed/simple; bh=lCDA4yX0EiiVvikZXg3OZKxvPdErg3I7teD56pWUdSc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Z1yZS2luRNaMtTwL+iARNrxGrK3zPMMffQRtLyDKhd42N7JI52p9Sgwx3v7v3ftVeTjT1oB7HWQLFMrKtgrsFPabAvEDba1ZH1C5SpxpMGYkhsokNzCSlMh1PSnfHl6rm4yJ7JeJ1lWdGcz45bZqAIruTrB/tcmKyaC4X1vcAz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YpvfLOTa; 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="YpvfLOTa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 765881F00ACF; Fri, 4 Sep 2026 15:59:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788537547; bh=zfKwgS89VgcL+3lr7dwlqUBEbXL7B71YIg7hP62axH8=; h=From:To:Cc:Subject:Date:Reply-To; b=YpvfLOTaH7OVaYfKZ2fIAXCjBTyOjF5sYv0eH45fnPyFs7zL+Xx3KucIXDpM2uuiS eH+9OqC/YOjBjPblYyUBkSKw8qWY53NP3pgE05QRgDxMmw1labymXyRRDUnX1Zv2du rhkWF3K9MDOtXtslvvz6auu3KARr04YEscLjKnFA= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80859: fuse: fix missing barrier when checking io-uring readiness Date: Fri, 4 Sep 2026 17:53:26 +0200 Message-ID: <2026090402-CVE-2026-80859-7c46@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=2360; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=oQWw07ytG2pWUdXjh1gcwOQoS/8aK92oGg2lUYV+tNA=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmzXsYplSz88Sb2ds3zQy+Fz87c8aKgcYLxRQ7f63Om+ TBk7Q4t7ohlYRBkYpAVU2T5so3n6P6KQ4pehranYeawMoEMYeDiFICJ3FFgmCu075DoIe+u1Vey 9Qus3tc8sj1weBnD/MK9chf0gj66dLGr/V4mrFPPcaLREgA= 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: fuse: fix missing barrier when checking io-uring readiness fuse_block_alloc() reads fch->initialized and then fch->io_uring. fch->io_uring is set before fch->initialized, ordered by the smp_wmb() in fuse_chan_set_intialized(), but fuse_block_alloc() has no matching read barrier between the two loads. This may lead a CPU to observe fch->initialized=1 but fch->io_uring=0, and skip the check that blocks request allocation until the io-uring queues are ready. This can reintroduce the lock-order inversion deadlock that commit 3393ff964e0f prevents. Add an smp_rmb() barrier to pair with the smp_wmb() in fuse_chan_set_initialized() to prevent this. The Linux kernel CVE team has assigned CVE-2026-80859 to this issue. Affected and fixed versions =========================== Issue introduced in 6.14 with commit 3393ff964e0fa5def66570c54a4612bf9df06b76 and fixed in 7.2.3 with commit dd9c835709f4bb3e4256eea7573e4e6e18f956de Issue introduced in 6.14 with commit 3393ff964e0fa5def66570c54a4612bf9df06b76 and fixed in 7.3-rc1 with commit edb310bc27f0ad83e7fd558a3caf1a94ca511654 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-2026-80859 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: fs/fuse/dev.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/dd9c835709f4bb3e4256eea7573e4e6e18f956de https://git.kernel.org/stable/c/edb310bc27f0ad83e7fd558a3caf1a94ca511654