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 5DE5114D2A2 for ; Wed, 19 Jun 2024 13:38:55 +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=1718804335; cv=none; b=Yz3KklzC8WE5SSNUKvg/1fQZo9Lzt8s/n9mI5zzLF54wqKZdV/KFqEOICqC1twZoJcaTk+KNlCmkEQMk6DxtSxAaWXXAJpNBMVKpuzgc1OtioqkxCYN4LCqGXQO+/U7hlsh6o1qzwPeukJ3A19vzNmx1bRNZ7u3tGNOrdJKOBmo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718804335; c=relaxed/simple; bh=750fcLoQr4ZAP5AHPKi+t38w7qdN2DA2HvDsY09fjao=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=h3fhZLnQBHPyBZBXzCRFKLRLcAlHikemp/oZPjjDFfHgwV7Vt9am+WkFCXpQwpqCCRdWsR2qeix/de/BAlHhvwFtONiM7VkTJ63JUAIpKc9oZcOkuCAWHWeOEUxgiwaVjPtff+FAV02bpMeBtOl/f73MrAYnsVFh5zuPLP4UI88= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AaiAWDYO; 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="AaiAWDYO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88F50C2BBFC; Wed, 19 Jun 2024 13:38:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718804334; bh=750fcLoQr4ZAP5AHPKi+t38w7qdN2DA2HvDsY09fjao=; h=From:To:Cc:Subject:Date:Reply-to:From; b=AaiAWDYOWEPkiBzKiTL4W2ViuhEQ9UuFAPIdL5c7nzPFwKnO9nRmQuVU6R6/rctex 87+EgT6HzpOGzUSSQNJw8jefAqEdAZKf3qav1WLfdibxv+EvKEoy7nQKvncb48QmPL fc5ft0dKjbobeNU3BDzTSyJWpX92qExCL794htzo= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2024-38580: epoll: be better about file lifetimes Date: Wed, 19 Jun 2024 15:37:52 +0200 Message-ID: <2024061948-CVE-2024-38580-d87f@gregkh> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=2369; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=750fcLoQr4ZAP5AHPKi+t38w7qdN2DA2HvDsY09fjao=; b=owGbwMvMwCRo6H6F97bub03G02pJDGlF93VuLmxS5v4kx3rszhx/Oc8juuHxKt8VZV5slOXQn XHs7JI7HbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjARpXCGuTIcB3evnGjMeF74 6v/FWgZuQgtW/WKYp5Sy9vtf0awVFsoVm5K9SrdbvErJBAA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: epoll: be better about file lifetimes epoll can call out to vfs_poll() with a file pointer that may race with the last 'fput()'. That would make f_count go down to zero, and while the ep->mtx locking means that the resulting file pointer tear-down will be blocked until the poll returns, it means that f_count is already dead, and any use of it won't actually get a reference to the file any more: it's dead regardless. Make sure we have a valid ref on the file pointer before we call down to vfs_poll() from the epoll routines. The Linux kernel CVE team has assigned CVE-2024-38580 to this issue. Affected and fixed versions =========================== Fixed in 5.15.161 with commit cbfd1088e24e Fixed in 6.1.93 with commit 559214eb4e5c Fixed in 6.6.33 with commit 4f65f4defe4e Fixed in 6.8.12 with commit 16e3182f6322 Fixed in 6.9 with commit 4efaa5acf0a1 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-2024-38580 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/eventpoll.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/cbfd1088e24ec4c1199756a37cb8e4cd0a4b016e https://git.kernel.org/stable/c/559214eb4e5c3d05e69428af2fae2691ba1eb784 https://git.kernel.org/stable/c/4f65f4defe4e23659275ce5153541cd4f76ce2d2 https://git.kernel.org/stable/c/16e3182f6322575eb7c12e728ad3c7986a189d5d https://git.kernel.org/stable/c/4efaa5acf0a1d2b5947f98abb3acf8bfd966422b