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 B871F352036 for ; Sat, 15 Aug 2026 06:11:00 +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=1786774261; cv=none; b=PrMqZSM4RoGz7SNAlJfpk1uMS5gPGnK4h0hKDJJnOApopddsKisB3Dp9uCR2u/IHMbPAEyj/G6RFZgOeZIRm30QHqU8pAg/cimiPnXxvQpxtGqImnt6LFRGz2meWpQKYythEzKrAQI/Et7BMmk+p/NMbCAV2JJOsr0cdojxEF7E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786774261; c=relaxed/simple; bh=uOk/6MDBtEOW+GCs/Nv57OQIfc0auM3CALi+KN561mA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Qxl+VUgEM50sC2NT7UH+uIBE6Y0FBBbPz8jmU5295ZVWhiReOxSoHLIRVGw1DvLZgrvvnC0Zvq32/iN3N4/uMTqoC1CWLvR+H6fEca94naanbVfVw0auKEJRMmWyckWx98FNhPhh1KWwBCPIglbB1SLBGzttYuRuHmd08jpgysk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oI2WgdU5; 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="oI2WgdU5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D0CC1F000E9; Sat, 15 Aug 2026 06:10:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786774260; bh=NSrFqLXhhcK95dc18IzkDXTNRKQ2mKrKOg5hhAFKutg=; h=From:To:Cc:Subject:Date:Reply-To; b=oI2WgdU52Bx8/ijiBhOwM4gBed20xK7xt74pIAqdIl/5IksSsxp02eaWrnYjKpZiL oMXKR6rCL1MAIJMhWHevsQW5o9IcwUnu6UvyW6zOCvYT7rUrmO6gimGnRc6nLKtSC8 okVVehyQ8BwrV9wEWIitbEG4wk62LXa3wr7+m5WM= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-72094: dma-buf: dma-fence: Fix potential NULL pointer dereference Date: Sat, 15 Aug 2026 15:02:53 +0900 Message-ID: <2026081523-CVE-2026-72094-78e8@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=3002; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=vNU/Kco4hw8coPGPMltEAFiSZmK2oJen8gyUXfUespY=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNDJs3vqmeeeRFyxxjJgnTg8u1z4Rcm6pRxWnqWtp2f 6VrDNvTjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjI5WcMC45cTBZRsFt0eUe/ 0c+Gi9dDmFXn+TDMT73scPbmmggJofYNAj/rY4ValPh+AQA= 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: dma-buf: dma-fence: Fix potential NULL pointer dereference The commit mentioned in the fixes tag below introduced a mechanism through which fence producers can fully decouple from fence consumers. This, desirable, mechanism is based on the fence's signaled-bit as the "decoupling point". A sophisticated interaction between RCU and atomic instructions attempts to ensure that fence consumers can still interact with fence producers through the dma_fence_ops (callback pointers into the producer). This is the desired behavior: to check for decoupling, the signaled-bit is first checked. If it's not yet signaled, RCU ensures that the ops pointer cannot yet be NULL. Hereby, dma_fence_signal_timestamp_locked() first sets the signaled-bit, and then sets the ops pointer to NULL. Readers first load the ops pointer, and then check through the signaled-bit whether the pointer can legally be accessed. These set and load operations could occur out of order on weakly ordered platforms. This problem can be solved very elegantly by using the ops pointer itself as the synchronization point. The pointer is either NULL, or cannot become NULL while it is being used thanks to RCU. Replace the signaled-bit check in dma_fence_timeline_name() and dma_fence_driver_name(). The Linux kernel CVE team has assigned CVE-2026-72094 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1 with commit f4cc3ab824d6772a48ca9d9c74ac623b3309985d and fixed in 7.1.5 with commit 15ecfdf0ef6f6d874d0a26690d300857b39ebfd0 Issue introduced in 7.1 with commit f4cc3ab824d6772a48ca9d9c74ac623b3309985d and fixed in 7.2-rc2 with commit 035219a760edb35ae9a9e96beba7f122e26a997b 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-2026-72094 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/dma-buf/dma-fence.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/15ecfdf0ef6f6d874d0a26690d300857b39ebfd0 https://git.kernel.org/stable/c/035219a760edb35ae9a9e96beba7f122e26a997b