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=1793829067; b=AaASnB/A6yAEXggTRrfOBp5JLZxVMTJ0Ib0N9bA4T0vonU2IbosEN4ESPnyDsqxlipx5 vOrW6Q4cMH74Pkbmq2n6BN2oLftvNmvIE7Mp5io81sAgNaE1+uCkT6f1aoZIShaT6qIBe EDqOclZbRRbiJXORheZ46JfwFcE9AuMElieqkOC0kTGoMFvDwASC12Ok9XI/iOaGOn8Ax yzC2qZ5TPAbEHN5WAjzSLF6d1hNynsyQ4u7VZ5q/JnpojhZnB1pR98gIZM6ZVnSP21g0j y77f/dJfkIVk28WlBvYClkmipsvWt/+04YsL2wvZYeLupI8Tde2Puoqlkx0zDdR9x4g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793829067; 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=64Xlz3Z6aROe3FQUJXEba+JkA5utEyL5aA/rQSA8+Q4=; b=T5rmV9yZ6i5sLtgTyRVE3mdUeGJHrDGb2JKO3Yi88haVWY5COifaCknDfej2Q4HZQRUx 5AmKmwkdlQKfsFnoNnZ1WBCmm/T9/49uK0wWfUXIYWEa8yUYqI8N9xdGMcYPKtIKOgTg2 A/kp9/RXL5OjvtAQgs6Bg4tBcwXukcMZvVHkAas4i6kiTcB712/oKfdpGpt93STtBpP+e Fd1dWiI7TbHNL58+WLRzLyd97GE21ckZ3zcYGJAj9Gpaesi4ilfWHPax7JwrJ209MqujG 9sc2ssKL7Ha6k4kQ9aBQIm8rWOxy3/iz/MpxX/oJTYCz/VEFHaZ+Ku8dYUMkBM3eT0Q== 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=bSUeaPsN; 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 3D0786070770; Wed, 4 Nov 2026 21:51:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=bSUeaPsN Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA2C31F00A17; Wed, 4 Nov 2026 21:51:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793829067; bh=64Xlz3Z6aROe3FQUJXEba+JkA5utEyL5aA/rQSA8+Q4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bSUeaPsNhfuP82bfVNmxzxQFt67PC8rVfr/BbC8vq+pTKjPssFggGKDfyttYZQEVd HG/FMiTtNFD7lkS1etj80/ZkorlsSdLoc2eU1bzowypkQWMiID1IiTIlQWRvOnuVA/ g9AcaS5F7kTbHBfLTSuaL+9Ro293+Y+WCUO+Kqp4= 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 7.3 422/547] nfsd: hold cl_lock in client_has_openowners() Date: Wed, 4 Nov 2026 16:10:06 -0500 Message-ID: <20261104211050.328940379@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211038.406938024@linuxfoundation.org> References: <20261104211038.406938024@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-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 @@ -4242,12 +4242,18 @@ 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)