From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794061724; b=TvydIIQr8VUI8vBvwNxKePNqssgXkLVq0YTi/NhLM7cmU9bQpJCKjx0/hHArnyDyF+AZ bohMN/1EAHKN8CB2uZQw4Vcxdann+bNEWcJzcpO4idFFVAtQSoAJRJ/ETO9zxxDuJk/Bh NVofoAlwr0+i1tGSlLFufjKSiT7huLCj1qWxuSFpufRy42rcFOa7+L1TXCQ/eeh5J63U4 6IbT7207HmZ5HbpBeDcr8H3UbBdB34vTSUWGpLJD6/lPdaux0LSRZ3xXPE1EgMU2+/gKh dkWvxq34k/f1lmrrrdOA3dVYBqdEdCevpMh/mRhf27g4GNN/4DViFBCP7aiMl61L08A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061724; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=CjflSGaanok2DrLpmCpUMAr+0FUmJWcwDF4aQwMTaCw=; b=h/Z8gx+WO5Lr64bEMGaXqcclypsFU4Fv8FhZUwLTOU7+iGfgvD5UO+qeo5K/ASOgpIOO gfBo44u/PwJ+mcbnx8aC2APOf94S3xzBx2TvhrqB2KOpI7xbqzk13EQoqsFAWnTfTuTkd IxnFG9dfud6adJCfH4NVM+JTqkqobHNIwyPHn0MGWfdwQRWjPBk0WqczMfEUF+d68XlW6 SmnMFo9VTKfy9O2VuNyf20+6NWw0WUVhRnrx3jl+rH1bC4h6F8OjK6XXfja5nLtMchQwI tiSogvbKmRUwtxRW/GrSeNpjsVMsW5hFserhAzwNC9Dxj4scb+rMG6f7HF2tAKLD5mA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="QoVc3E/e"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D17F606A331; Sat, 7 Nov 2026 14:28:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=QoVc3E/e Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18E641F0089F; Sat, 7 Nov 2026 14:28:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061724; bh=CjflSGaanok2DrLpmCpUMAr+0FUmJWcwDF4aQwMTaCw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QoVc3E/efg8L7AjDXBzxqTakdns3CnHapUrlq103feZ/Lg2OLXKXgoPyX+SDgyWf4 rou+d6I5U4qhbMPRZ/V1DkpzAfe9buB2/ALgmaqzUCVo8J+opxguDfdaI/GJwcG5af yli2xoi544TjprkcDIdk0qz4Bsf95nLPGhM0nXfM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Xiang Mei (Microsoft)" , AutonomousCodeSecurity@microsoft.com, "Cen Zhang (Microsoft Security FORGE Labs)" , Chuck Lever Subject: [PATCH 6.12 0768/1536] nfsd: hold cl_lock in client_has_openowners() Date: Sat, 7 Nov 2026 08:46:24 -0500 Message-ID: <20261107135019.103286830@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cen Zhang (Microsoft Security FORGE Labs) commit 5336899b5491eaa2ac22c2925d87daab2b140eb3 upstream. client_has_openowners() walks clp->cl_openowners and reads so_stateids without clp->cl_lock. nfs4_put_stateowner() unhashes that openowner under cl_lock and then frees it, so a concurrent EXCHANGE_ID with mismatched creds can use-after-free the nfs4_openowner. BUG: KASAN: slab-use-after-free in client_has_state+0x10a/0x140 fs/nfsd/nfs4state.c:3718 client_has_openowners() nfsd4_exchange_id nfsd4_proc_compound nfsd_dispatch svc_process Take clp->cl_lock while client_has_openowners() walks the openowner list. Fixes: 4eaea1342507 ("nfsd: improve client_has_state to check for unused openowners") Cc: stable@vger.kernel.org Reported-by: Xiang Mei (Microsoft) Cc: AutonomousCodeSecurity@microsoft.com Signed-off-by: Cen Zhang (Microsoft Security FORGE Labs) Link: https://patch.msgid.link/20260828041925.36758-1-blbllhy@gmail.com Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4state.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3641,12 +3641,18 @@ nfsd4_set_ex_flags(struct nfs4_client *n static bool client_has_openowners(struct nfs4_client *clp) { struct nfs4_openowner *oo; + bool found = false; + spin_lock(&clp->cl_lock); list_for_each_entry(oo, &clp->cl_openowners, oo_perclient) { - if (!list_empty(&oo->oo_owner.so_stateids)) - return true; + if (!list_empty(&oo->oo_owner.so_stateids)) { + found = true; + break; + } } - return false; + spin_unlock(&clp->cl_lock); + + return found; } static bool client_has_state(struct nfs4_client *clp)