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 9A5593BB9F3; Thu, 9 Jul 2026 18:47:56 +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=1783622877; cv=none; b=rpNA7Ij1M4zFKiOgZDYlwxyK3q3MCcIKXPWQc219AoXsrA6YI+Kc4FkR2zVg1IJqdb3kW+6fB244SPja6X5aa6KX9tf2bKVXTzFeU53Jtts3SWTWDIBbXJ9fd2UkiAZAmdn9pJWQXZtzD97l35m0vC68emezyJiUzjCkTbZKHQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783622877; c=relaxed/simple; bh=rfKsUyMbAxU1oFUkwyRq1/50EfZPzhSWnRTiX3/XtXo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=TtNiku5XyaEqVWzejqyLkCOnrrd5QKJX7gb2CyKoOWv6aDk16OBrR1QhRq9Mg2bln0rgrOD1BFFzVosDIVXgiLF4DftQxFeRqB8sKHHO0cxwjf7+wXQuEvr8EzVJx85xRA4xyh8ou7bjets8shfJZWigChA8DQIHh/nk/97Y3Ys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vig/Yz7O; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vig/Yz7O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C33491F00A3F; Thu, 9 Jul 2026 18:47:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783622876; bh=0WvleFZ1GxnBtowhUEbZuiqr/eM3Qx8KSK3wmd5xtrM=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Vig/Yz7OnnGIDxcAIHVoTS6o8sQpu0lL4L0KCCvAz4jUtty4Y/4+OY12Qsagu9aIN gdTkYhQXZ48OLdGj+YZvSiFw6rXDfjowcthwflMSp7YmFbe/XHV73q9MX7NpZlfkzz i6WqS+EI9yfgU4viISuEKC3DDjGTJtGzL8/n/atIxZSLAB8GyejSvlScI/ZVQdJkvL 9hPAOm9I4Wib+mZXGT9CH7k/CRMSfE03Nj3ORRYfmh8CNXBBu1gzlVH4fbBciSYtBs 4ApQWDhUvHYAvcwzFIjFgKaPk5ZBgPhuRToalWPA3yaBt4GoEiJGG6lbenKe3AV65A DUHkifgftXrxQ== From: Jeff Layton Date: Thu, 09 Jul 2026 14:47:42 -0400 Subject: [PATCH v2 05/10] nfsd: check client ownership when cancelling a copy-notify stateid Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260709-nfsd-testing-v2-5-0a1ba233bf87@kernel.org> References: <20260709-nfsd-testing-v2-0-0a1ba233bf87@kernel.org> In-Reply-To: <20260709-nfsd-testing-v2-0-0a1ba233bf87@kernel.org> To: Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , Andy Adamson Cc: Chris Mason , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1682; i=jlayton@kernel.org; h=from:subject:message-id; bh=rfKsUyMbAxU1oFUkwyRq1/50EfZPzhSWnRTiX3/XtXo=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBqT+zVFgBBQxEJScuufkyI1Ko7OpfOCL1LJhdui tVmgOchRdCJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCak/s1QAKCRAADmhBGVaC FVepD/4qTguoZV2Ns3fQkLoCiuON1A3Y/m5j55X2POoPD40OZClwTrR8yl3JRcr2zMirFY/LpOX otJBu+9RoMmFcwUQnyVlveOZ75pCMNkTF+I9mfD2iEuyfiui4JCmWLwUztgbc3rPQT/kVMx/ucB chnXjY9VBESupqtQRvruewPgLxr6bDJoKIzWaSu6x6vlZROsa+h+0Ph5jS/EjKdLBQRLZoCQvS6 dKMBqkU2fYUHAInlhfhGIxSpBhy4SKJA2Y8A33hz9/Zq2ojeregWLDqnTKrC23a/rh9EtcgFOWy KZNXX3w+aC72lbXYnGoDxk6SWl1Wtbr1PRSf/j915JhjygIXZCPppMHIVnDp8FzWZIVmCn2U2HN be46XeFPG7/0oB0MdQ0blc7wYIkX9OpAH1sq/xLxaW69rH+tVBQtxnZ7AObavdLJtnZFPZqeTja u6TMfI66vq3zJwAy3hh4VI3faZ0j/Wf4fCvO1QvB9kMRK5IrNr0pXvEDLPvMhcln8IU34FUEOne M1Zh6+8hj5wlE6rmIXls0d1pBHAyWw+Fa8iYug4e+s4w1xO84C0vIHwfXflnlacQnIFfPPrXpht IAillN48KzpLr6ppPSEq97moSwWDClQiayBi9Wv7dXH0HR60nwIJr4XisgOQWgXi8yshnrgZE85 qSawf28VdbbT/gQ== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 On the OFFLOAD_CANCEL path (clp != NULL), manage_cpntf_state() freed the target cpntf state without checking ownership. The lookup key st->si_opaque.so_id is allocated cyclically (guessable) and the embedded clientid is the fixed per-net nn->s2s_cp_cl_id, so any authenticated NFSv4.2 client could cancel and free another client's copy-notify stateid. Compare the creating clientid recorded in state->cp_p_clid against the requesting client's cl_clientid and return nfserr_bad_stateid on a mismatch instead of freeing the entry. Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Jeff Layton --- fs/nfsd/nfs4state.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 1ef015cbc055..76c0e08711df 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -7916,10 +7916,22 @@ __be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st, state = NULL; goto unlock; } - if (!clp) + if (!clp) { refcount_inc(&state->cp_stateid.cs_count); - else + } else if (memcmp(&clp->cl_clientid, &state->cp_p_clid, + sizeof(clientid_t))) { + /* + * OFFLOAD_CANCEL: only the client that created the + * copy-notify stateid may cancel it. so_id values are + * cyclic and guessable, so without this check any + * authenticated client could free another client's + * cpntf state. + */ + state = NULL; + goto unlock; + } else { _free_cpntf_state_locked(nn, state); + } } unlock: spin_unlock(&nn->s2s_cp_lock); -- 2.55.0