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 80CBB57ED89 for ; Fri, 11 Sep 2026 20:02:04 +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=1789156932; cv=none; b=N9wC7KXITIL9JbABobbN/lXrCB8hJ+NyKrE+t1FMegPgWEIy+tHIcRpJCm0rUMPQMOReyDuozAIp++rJqDAnG99i+HtBWWjdiBMLPxMi3aQV4a3HfydkKReB53fra5QnGWKOvTpMkC6KFtXQioZH4MX+ansi5ArWei05++gP52w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156932; c=relaxed/simple; bh=CX5CyyEmvRv4N48I6RqVhHsprQVIn0VG8L8brDUTz6Y=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=hnjBixl/LkHm8H61i71lFQZDGHSS7G01j1GFLNrXrj4OeoJacqyVuVfyJsELc5eQ3W8vLI3mR6zsP2SIScB5glB/ybWNANDJYKTDVjgA8TyOuXajBT0ocAu5pA7c8y/DEGRJdc34fzAz1NFg+8VPSlDmUo5xOEbmXsmtbD4lRHI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Z+zAJy9h; 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="Z+zAJy9h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 915001F000FF; Fri, 11 Sep 2026 20:01:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156919; bh=tGrxjEUs0FOq/yK+2O43Q9VIv2huY3v+tdS7sacv3ss=; h=From:To:Cc:Subject:Date:Reply-To; b=Z+zAJy9hygW59jbKCPo4CVSg+kUnOMGnXScFHEBkfgq474D8Zn+vNmJ3hMEL0PDmf avbNkH4tUg/t4zSsf4RZvWv9LP0PkI1tuVyobFB/uCdwy+9HabvN3xhl6f2Htlav/3 W6KoQdT3lZi/I+gh1Tx2prc3vQjLqkqDUM4RlBw8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89677: nfsd: fix possible fh_compose of wrong dentry in nfsd4_create_file() Date: Fri, 11 Sep 2026 21:46:06 +0200 Message-ID: <2026091150-CVE-2026-89677-6379@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=2434; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=CGJv/R6wdWf2RmbHBY4G49jSdF4zkphnSZ6Z1+UGaG0=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIusEX0vemjg3Pk1Hrvx9a++Hr7P/vrCumf4ggE2/v vBU0ErjjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZiIrT/DPPM55gUaxf8//THd 6B3zeabe0r3n2RkWLHDJvtx3aG8q4/vflzQKbr2ec11pPgA= 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: nfsd: fix possible fh_compose of wrong dentry in nfsd4_create_file() dentry_create() can hypothetically provide a different dentry than the one passed in. This could happen, for example, if the exported filesystem is NFS, and the server returned to OPEN a filehandle which matched a directory that was already in the dcache. Clearly this would not be expected! If this were to happen the dentry (child) that was already stored in resfhp could be freed and later dereferenced. We shouldn't call fh_compose() until we are certain that we have the final dentry, so this patch moved the fh_compose() call to two places: one for the case where the target already exists, and one after dentry_create() where it was created. The Linux kernel CVE team has assigned CVE-2026-89677 to this issue. Affected and fixed versions =========================== Issue introduced in 7.0 with commit 64a989dbd144e0622371396461b11335459692d2 and fixed in 7.2.4 with commit 033e783709ce99662cf81f6abcad746a8da9d35f Issue introduced in 7.0 with commit 64a989dbd144e0622371396461b11335459692d2 and fixed in 7.3-rc1 with commit 3e2c79360c6a89975ec5b5a7d4ef937e4db91a27 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-2026-89677 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/nfsd/nfs4proc.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/033e783709ce99662cf81f6abcad746a8da9d35f https://git.kernel.org/stable/c/3e2c79360c6a89975ec5b5a7d4ef937e4db91a27