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 9C99058F09C for ; Fri, 11 Sep 2026 20:01:58 +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=1789156933; cv=none; b=cQhaYspWI+b9n+OkJbscco3BJqgdipaccBLtKaYN9sKpXZUt3HF07ti5ELXciPbItRpf2dzTnYyQdKLzkCbnq0w9V8b6jqEeFFEvvZnepYkzV/nC+4a0ZJmqD3tsmYeQM6tkgPAmVia8JfJuT2JW331c/qKphUTKJvGtOqLKTyY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156933; c=relaxed/simple; bh=wlegQW4SM9sKPorNmF89Wp558tg7UpFsib7MVCnejzk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MRDp5awXjDlvGRweqbpPpwaPToQkOT7pCYmTiD9+Cn5u0xgh2SGPPmj5kyxfFO+B+dFHLb6BBJdWiAxt5CYr1htYkhoKPZJqjmAj6Yos6l2PNire5l57kXjQ0wlwImT2PaOibchqFgTTMf+WjORf8TLwzskldOfiLDtB/OS4ABc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WXeHLHMY; 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="WXeHLHMY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A89B1F00893; Fri, 11 Sep 2026 20:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156916; bh=NCnQBv52uOLsGiIzGakTlbAOGZRGMMi8vzFJIlAAl1s=; h=From:To:Cc:Subject:Date:Reply-To; b=WXeHLHMYBQzXiHV8FUaPFgpUnXi6wkcSQy5cW5/MaT9q2CWBDNPnwh+Dzj6sxD2ff XPQpG2TeY2S1U0qeamEg6vuQDr4I3+X4Pcsr7RPqVH/gqtBR/fvJnx0BgheZ3peYic XYJlVbe0uojUx+GDEJkB+a4GT5wimO5bCpX1BAh8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89676: nfsd: fix stale s2s_cp_stateids IDR entry for async COPY Date: Fri, 11 Sep 2026 21:46:05 +0200 Message-ID: <2026091150-CVE-2026-89676-47d0@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=2754; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=96GMre79EDhAc+sbK0TiWk+OoxNoPKJwGKK11rztH2w=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIutYGP02Oy2V3b1jmyw/J3eSUMmnV0lPZIWvPLwiy ij9/Ex8RywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAExEWIlhwdZYndvMMzUXx13+ eEhegT3ezoPXgWHBxv0/JwrNl1janejKVfF1pccsgVluAA== 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 stale s2s_cp_stateids IDR entry for async COPY For an async COPY, nfsd4_copy() called nfs4_init_copy_state() before dup_copy_fields(), so the s2s_cp_stateids IDR was pointed at &u->copy->cp_stateid -- memory in the per-rqstp COMPOUND buffer that is reused by the next request. dup_copy_fields() copies only the value into async_copy, so the IDR slot dangled at the transient buffer for the whole background copy. Any IDR walker then dereferences reused request memory: the laundromat reads cs_type from it and, if the bytes look like an expired NFS4_COPYNOTIFY_STID, follows into refcount_dec()/idr_remove()/kfree() on garbage; manage_cpntf_state() has the same exposure via idr_find(). Duplicate the fields first, then register the stateid on the stable async_copy. result->cb_stateid is unchanged. The Linux kernel CVE team has assigned CVE-2026-89676 to this issue. Affected and fixed versions =========================== Issue introduced in 4.20 with commit e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 and fixed in 6.18.50 with commit 9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a Issue introduced in 4.20 with commit e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 and fixed in 7.2.4 with commit 14b978e8d05ce018d0afbeb6611833ef91713a02 Issue introduced in 4.20 with commit e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 and fixed in 7.3-rc1 with commit d0beaee498e11880e72826026db0e9c9890fc114 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-2026-89676 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/9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a https://git.kernel.org/stable/c/14b978e8d05ce018d0afbeb6611833ef91713a02 https://git.kernel.org/stable/c/d0beaee498e11880e72826026db0e9c9890fc114