From nobody Mon Jun 8 17:38:08 2026 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 6FA613BA241; Wed, 27 May 2026 18:30:50 +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=1779906651; cv=none; b=tyEnxO+KSLm7n3OglE7DJNdgkY9z5nwk/MwUWO0f0Gd3jEU0YJPLL2+ertBmjxvM909y/agKR+8Fg/lFaCIWBoD+y3R9aYGIQ9Hn8L0mAdiTt7IUgYaomBCE+OfZ153rJNe5EbFONQEyiDNsHfn2RNXrYxIO2HYZpuG6nXSLbUc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779906651; c=relaxed/simple; bh=ZANtEzuGC5cyemDzaR0P6OArQ9HQd2EvvZiHu816dBA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=JfUkDLva/rkO1TDOm43zvoF1uVEtmuWMg4KavVb86UVkBsD+R9ltkQRz9RMaK4+IGwrBfjeZlDmJWIc72j/8Y8wWiKGLoKrgpeqcPnraaWtdgdXIJUI5YqaLzZBuHzdFtl598kqAz23SiRRiRkaFVp0Yk0Vf1lT6+Npzm2gYrvc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PMsw7Bx9; 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="PMsw7Bx9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B9271F000E9; Wed, 27 May 2026 18:30:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779906650; bh=+8kZw9j4jyv71Pq5CFD164U5DTMxo9JNNcbMN3/oa7s=; h=From:Date:Subject:To:Cc; b=PMsw7Bx9DVyxf8AiRCirKDJ5VaqGMhw+W53R0p/7Y+qX9IEtABZ3RdWFSeN/GTEdV 0gyT0uIz5Why2isynbIvW3sox501IhYuDaNyhRCF2oU4GFmQO5YjdAp+i8Kye839x2 TJKZqocPzYnOaq17tum/TFgX8fZUsunVTuRK4WdCk0L5g+gk8LRROs2k7FdXI9oBBw VjcWkV/VtwFPwMAbsXr8x8bEP2rUvVT4kZRwWGMZDbKw8nOmsWQ/SDUaOifSkJz67P 6MVT4yBmwmJJTaWjBPhpIWBTYWUGRO5xMFVtylNRBGRWFyilqcbQuzLIzp0361wnw/ u9kAAneKgKLaA== From: Jeff Layton Date: Wed, 27 May 2026 14:30:41 -0400 Subject: [PATCH] nfsd: fix XDR padding calculation in ff_encode_getdeviceinfo 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: quoted-printable Message-Id: <20260527-pnfs-fixes-v1-1-784f39dc1eca@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDUyNz3YK8tGLdtMyK1GJdI2MTU8OkJAPjFFNzJaCGgqJUsARQfXRsbS0 Aeht3BVwAAAA= X-Change-ID: 20260527-pnfs-fixes-23451bb03d57 To: Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , Sasha Levin Cc: 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=1509; i=jlayton@kernel.org; h=from:subject:message-id; bh=ZANtEzuGC5cyemDzaR0P6OArQ9HQd2EvvZiHu816dBA=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBqFzhVYCnHfvYxBd+pHRdXUTvnjDis1aL82VAY2 Ux0nuT5nd6JAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCahc4VQAKCRAADmhBGVaC FSh7D/4hnRt78c4nDL3wQIUgdgO92BmwrG24g/7Xjff7Hs6ltR8+eUk8rh9ESfOnvb7ZMjKQ+vn nE++/r/aiJUwMLguek86vJPMrkd24kLHEBV09jNkKqq4FeZrTa0xHVMc/Cn+r73BCrYDMWKuLnh 71cOp6GCTgrCjOzHVWBhAQeHZ73sGBwthEhcUc6Q88Hbf/Fn8A15kM4kJz0rl55UuNZ4rzO9tOs CaJTb3TgEgwpODsQJvqL33lvZnXQilym3b+m1DmaeotUMZBntaW2rQXlVFOuSjXrdSmr2xNY1t3 DDQunqvHoEKgcUD6QLByQ/PSpphcHe/Ei9/vPSpyQMwwRSDrdByooU3cjzikGcw/e7OlAbiffNq Sp31vg5dFcExMDbS4PcBAOccOnZrPhodl6EPWVSSFR8XmeMH8tFU1j3IOO6htvumQISl99k1qG7 lLq+oyEwy+Xs4b3QqPjc7iB0DkPmAGngEfHlLq/wjV1U/S1F+7KxZ4iTRg31DznKmSFZCc1meuV dDf6wR8z4rYrPhVr9TtnQdVGxNW2kW9zGsxW6HJ6mpy0/n7nr8k4oddrRjbFLwLdbvJGm50NhO6 0E9KqUjRfEmq4dJu1kVSUqRZ51Kpq8DufY/HR3nP/Ioxh6DZvZ2IILxfjCGOMGMwv0T3/QsoYwR M7tF4gNNzQ3P8lw== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 nfsd4_ff_encode_getdeviceinfo() computes the da_addr_body reservation as 16 + netid_len + addr_len, but the subsequent xdr_encode_opaque() calls emit 8 + round_up(netid_len, 4) + round_up(addr_len, 4) bytes. The mismatch means the declared da_addr_body length exceeds the actual encoded data by 2-8 bytes on every flexfile GETDEVICEINFO reply, leaking stale reply-page content to the client and mis-aligning the subsequent version list decode. Use xdr_align_size() for each string length to match what xdr_encode_opaque() actually writes. Fixes: efcae97fa425 ("NFSD: da_addr_body field missing in some GETDEVICEINF= O replies") Assisted-by: kres:claude-opus-4-6 Signed-off-by: Jeff Layton --- fs/nfsd/flexfilelayoutxdr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/flexfilelayoutxdr.c b/fs/nfsd/flexfilelayoutxdr.c index f9f7e38cba13..7f357dbd1bb1 100644 --- a/fs/nfsd/flexfilelayoutxdr.c +++ b/fs/nfsd/flexfilelayoutxdr.c @@ -94,7 +94,8 @@ nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr, } =20 /* len + padding for two strings */ - addr_len =3D 16 + da->netaddr.netid_len + da->netaddr.addr_len; + addr_len =3D 8 + xdr_align_size(da->netaddr.netid_len) + + xdr_align_size(da->netaddr.addr_len); ver_len =3D 20; =20 len =3D 4 + ver_len + 4 + addr_len; --- base-commit: b69fc3eaa867d0caa904634ea7a1b4569411b163 change-id: 20260527-pnfs-fixes-23451bb03d57 Best regards, --=20 Jeff Layton