From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f5.google.com (mail-pj2-f5.google.com [74.125.227.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2EFC13A63F2 for ; Wed, 26 Aug 2026 06:49:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787726980; cv=none; b=Nk4sWlBZyBvQQyIU0L7Maq4mBZq44UpBB1g0Edq97a32osVVkBn8o9wlWTDAFuGfjsxp0b12bLnUjjHAzia5x4TCZHO82fRr+IZfRijyIev3F74bb12ZvVBSt1XESWdmXKRktTxxtYpn1/vZHiAA0XJHnicJxtxetUUJJ0JbxGs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787726980; c=relaxed/simple; bh=+s1q81uGzAC3EM5nOyVnAY7Asm3SuhxVuST/IBvgRZY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=P4gaova7WXC9njZPeOlkEMi7K1IVh56WxUHeUnZvgZXDFrt40yFkzUHPor11tJj3WAQiRs2uPwjo70wbKifHiwXMOSufuM55t+LF3zQwBB+t4PYiUIFn+f5egE9qlmnArhwYG5kfGwe5uGTCnlbW0czVCx9SP/aHDwV6IIAjNEo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=gKVK5lSI; arc=none smtp.client-ip=74.125.227.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gKVK5lSI" Received: by mail-pj2-f5.google.com with SMTP id 98e67ed59e1d1-39662b5cde7so489064a91.1 for ; Tue, 25 Aug 2026 23:49:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787726976; x=1788331776; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=S6+gZISuTotipjsrEyz9Cx/NTi3M8+6APWRf94zGuNA=; b=gKVK5lSIdesLrAP/4gXgIfkMNSC8GuC3igLWZoXRkqVilex6EG8vZAVPJTzQNzuXzy PA7TyS3JCb98ke6hARjLmmkE7OcjCfJFXRFNS5gIDOGJvkgWNKwDzhCeq0gm2hPRF6H8 qlZhF6ClpMuloSYO/HPPFxMQN8o5auYNCl1sxwaL2D0xsHVyiq3GqoAkg4v3mZYWoTsQ WD/C0AtEvS18DO46OZtk9nXyhCt3sbJHX2ZkLx7RVEu0tYkHTR4NHtCftVrbcWQuzOrd cacvBv4aVkUMafaom/oNUq24i7uJmgs6COdhF9AzDocDG4WctJc0gZSoeXXRtjzzGnDz SRig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787726976; x=1788331776; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=S6+gZISuTotipjsrEyz9Cx/NTi3M8+6APWRf94zGuNA=; b=b3g6mKG2PHdaN8aGvSG4o5ispH/y/Yn0Od0SPgbhU4Hcvokj8e+04iXS8X56lW//TH 9Z3D+w4cLIclP1O/lRcN85YF5SOcpVXLxI5gYDl7XQivQT8J6oXQYYXheq9dvh70MNGx UCJIyAHZmiucRqAxdrhy42wBecAKOdlxuM6UzuwDHMSt6/H7kuZga1AXiqnV1PHdGsIk dyVwdmbR2m9quJShxBqRiZ6vQc1YPs32UrCBQRbcjzCI4ifDwVa/ncXXIOOHUbkgUmKL JiwAO9/2DIKKmIs/8SWMPsvjFwZClFU+IOnip++znO/Z+AJ2oiZUKVE8gDOgjnWwKKNr +lJA== X-Forwarded-Encrypted: i=1; AHgh+RoH5DnhxQwpxvoIpWvG2eGcVCLy9yGXzDS6GH1UWQNvxlm4DHnsBbnSsI7PfLFnNQzBeqcNV5M=@vger.kernel.org X-Gm-Message-State: AFuF++nxVqmlAV+DF+JfLWmB7KiCiE7ARi70cfYPPC83DBffjwF3HGi7 e0RvhNInm9XclbcnY94WVOauqYTWxSfVjd75w3RpD4VzhJ8lxf1Zg3n8 X-Gm-Gg: AR+sD121gfmXQWwVGv7QMbEaPe7zdqyRRxYgVz/yMGPfCswNtNNBpo2SbnutQVd/C8g YERyH5dUrL7a3aeOtBs20zG4TO+jUSgTnK7InUbPXF3682jrSt9pAp4ffOgIRm22d4Z/vxDzzNP Ctoajg1+a+9IWgI+QnYwDxFXmsCtt/Z3nF3P0ZhCIcV7zh8ZkJmuaeCTZ5JYqECeOIM2/AlywjJ 2E7Z/OdpWcEdvQ1A14KH/KFIPnRY/kf/Ri3VYHAIt18JQgc7nZVQn2im3Af36Td69Sh0XMbqFpo jZxejnKBcagWjBzhszjffa6scsWXCeSx/NgL+Ch97in9tD0X/qkz9x3Fjk7ydYvBTfxz1BEo4HE evy7nrs3pdXAUcmMiSy7erwbtYO1qiwx65I4CLGmqXln+diL/CT50WmbZ5EsyFssXp/PJRDtxBa n96v6dQIdTwBvAa4JmI6+I+0+4iQVAOyS7IInB4F2pCzHaSg9ggHriwwdjZ7bO1VnhDNmlwCRFe M6PToAiz9bX21VOz9a2c0x84Q== X-Received: by 2002:a17:90b:35c6:b0:38e:fea2:df53 with SMTP id 98e67ed59e1d1-3966d3bd49bmr9980179a91.4.1787726975810; Tue, 25 Aug 2026 23:49:35 -0700 (PDT) Received: from localhost.localdomain ([38.60.126.44]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-3283da25c8asm6151397eec.30.2026.08.25.23.49.32 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 25 Aug 2026 23:49:35 -0700 (PDT) From: hoobnn <853555@gmail.com> To: ericvh@kernel.org, lucho@ionkov.net, asmadeus@codewreck.org, v9fs@lists.linux.dev Cc: linux_oss@crudebyte.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, sripathik@in.ibm.com, aneesh.kumar@linux.vnet.ibm.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, hoobnn <853555@gmail.com> Subject: [PATCH] 9p: dynamically allocate directory entry names Date: Wed, 26 Aug 2026 14:48:19 +0800 Message-ID: <20260826064819.52523-1-853555@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit p9dirent_read() copies names into a fixed 256-byte buffer. A name that is valid on the host filesystem but longer than that buffer makes strscpy() fail and aborts getdents64(), hiding the remaining directory entries. Keep ownership of the protocol-allocated string in p9_dirent and free it after dir_emit() consumes the name. Fixes: 7751bdb3a095 ("9p: readdir implementation for 9p2000.L") Closes: https://github.com/microsoft/WSL/issues/41192 Assisted-by: Codex:gpt-5 Signed-off-by: hoobnn <853555@gmail.com> --- fs/9p/vfs_dir.c | 6 +++++- include/net/9p/client.h | 2 +- net/9p/protocol.c | 12 ++---------- 3 files changed, 8 insertions(+), 12 deletions(-) diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c index e0d34e4e9076..af00b79d801e 100644 --- a/fs/9p/vfs_dir.c +++ b/fs/9p/vfs_dir.c @@ -185,8 +185,12 @@ static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx) if (!dir_emit(ctx, curdirent.d_name, strlen(curdirent.d_name), QID2INO(&curdirent.qid), - curdirent.d_type)) + curdirent.d_type)) { + kfree(curdirent.d_name); return 0; + } + + kfree(curdirent.d_name); ctx->pos = curdirent.d_off; rdir->head += err; diff --git a/include/net/9p/client.h b/include/net/9p/client.h index 838a94218b59..9f3079c6f386 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -268,7 +268,7 @@ struct p9_dirent { struct p9_qid qid; u64 d_off; unsigned char d_type; - char d_name[256]; + char *d_name; }; struct iov_iter; diff --git a/net/9p/protocol.c b/net/9p/protocol.c index 67b0586d807f..d4335884e0c0 100644 --- a/net/9p/protocol.c +++ b/net/9p/protocol.c @@ -770,7 +770,7 @@ int p9dirent_read(struct p9_client *clnt, char *buf, int len, { struct p9_fcall fake_pdu; int ret; - char *nameptr; + char *nameptr = NULL; fake_pdu.size = len; fake_pdu.capacity = len; @@ -785,15 +785,7 @@ int p9dirent_read(struct p9_client *clnt, char *buf, int len, return ret; } - ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name)); - if (ret < 0) { - p9_debug(P9_DEBUG_ERROR, - "On the wire dirent name too long: %s\n", - nameptr); - kfree(nameptr); - return ret; - } - kfree(nameptr); + dirent->d_name = nameptr; return fake_pdu.offset; } base-commit: 028ef9c96e96197026887c0f092424679298aae8 -- 2.54.0 (Apple Git-157)