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=1793980341; b=OZZkz8AevYnYGam3lsy0x0lrKLLVsN8rdVEiBGCSTvRrAlFlXt6VSF8eskustlQDJY1S SRv/j5MjVL9GRbz5x5BRDxYHan0eFy1AO3Xc6KmbPdcscPsrMSyEg4bvmeaStCMzey2R5 chhX1wQvTHRsdcIKMkVyY9jYHAqufPhLxkSJHS7u49nWlqMKJwfadB9QAlkQrIifjxVHw FbjmEfSYI9BQ0WTyUs03g2HfmuzSyQd+mvKrikfU9L+S2WTmNETJUnusgb4+7A0mpqLHV Q3tW8S5VabmsRKhSpg+MlcS4nRoJw/SkPsO6C/Z3vpZvD2jf+Xma/JBc0pr25Fyn9dw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793980341; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=tVxeufujTzI9HWysjAFfReuCDOgIHDgnaJ1AMH90bxw=; b=CYzPg9Z2qDBDLx+xEmZKZDqT3LApAbMfzJERfq7TIkK1ScI1A0lOHkKlPrCvajCw/Mcs 8GgLZ+ocm3j9XDrlmdViaei38HM8F7Fa6RFLfW5hKN0LHa6h+SR6dpubSF6Z0cw5hsLDn Uy8HE/7mX/bSPt/yvaRLtjLx5LHGovS467zFXiJAlAS+qHQPSRaIpkznJBLfIaqofmVNT Vk00ASgRxF9J++T0PGU3+vrVUgpsGBJnQexgyxBS5oHg+QQ+bawYXw63tZSDATKiLguY7 Ygimg8K4tAki5/aWirGzc8uWBOcz8QFQmkogJoHMIJMApgjEqG2/+L9iIojKyQFcHzA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="B/HhKmXI"; 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 C7CBE606A326 for ; Fri, 6 Nov 2026 15:52:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=B/HhKmXI Received: by smtp.kernel.org (Postfix) with ESMTPSA id 254EC1F008A1; Fri, 6 Nov 2026 15:52:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793980340; bh=tVxeufujTzI9HWysjAFfReuCDOgIHDgnaJ1AMH90bxw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=B/HhKmXI5hPNroOmOeZfdq+WgH2mwnvFygqfMo6+09Z6EkjmrgLAueTz1UA5J1WvA caRbEUaDWHjj3L+5NIMcZ6f0ooXtmEcT0upwYqyoxx5m9fPjkrmDbk6FWOn2enbf9I CHmIIJSi4SVBTIPvU5jgHzGYs3TDq6wRUBhPMMIRKWhYng9L/Jrn1pbSlKR7LLJ0De 4+++Dgr7bHw5DEa6wn2jOl4yHAjmJtV8VlDqDLlBqjhcplv0Y6TchJ2VMIQiqiOG5F DpJqB7DPyOt1kCjNE83igg+i6qda764HEasFRUJMuR6Ihfwwyd4jyaGwRqCZJAG3me 49KKaq38PeWOw== From: Sasha Levin To: stable@vger.kernel.org Cc: Gael Blivet , Namjae Jeon , Sasha Levin Subject: [PATCH 6.18.y] ksmbd: look up stream size by exact xattr name Date: Fri, 6 Nov 2026 10:52:19 -0500 Message-ID: <20261106155201.409535-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110444-union-header-f23a@gregkh> References: <2026110444-union-header-f23a@gregkh> 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 From: Gael Blivet [ Upstream commit 10ea20d6584ecdaf2f7505855412a856a88d8934 ] get_file_stream_info() walks the xattr list from a single ksmbd_vfs_listxattr() and sizes each stream it finds with ksmbd_vfs_casexattr_len(), which matches with strncasecmp(). Linux xattr names are case-sensitive, so two streams differing only in case report each other's size. The loop already holds the exact name, so query it directly with ksmbd_vfs_xattr_len(), which is what casexattr_len() calls once its search succeeds. Make it non-static and declare it in vfs.h, and drop the comment above it, which describes a different bug and no longer matches the code. This also drops a full listing per stream: casexattr_len() runs its own listxattr on every call, so enumerating a file with N xattrs cost N listings instead of one. Fixes: 689f1eb3719d ("ksmbd: report actual xattr value length in stream enumeration") Signed-off-by: Gael Blivet Assisted-by: Claude:claude-opus-5 Signed-off-by: Namjae Jeon [ sashal: retained non-const struct mnt_idmap pointers to match the existing vfs_getxattr() API ] Signed-off-by: Sasha Levin --- fs/smb/server/smb2pdu.c | 13 ++----------- fs/smb/server/vfs.c | 4 ++-- fs/smb/server/vfs.h | 2 ++ 3 files changed, 6 insertions(+), 13 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index a8a42fde4ca02..12e73fa159fc0 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -5275,17 +5275,8 @@ static int get_file_stream_info(struct ksmbd_work *work, streamlen *= 2; kfree(stream_buf); file_info->StreamNameLength = cpu_to_le32(streamlen); - /* - * stream_name_len is the byte length of the xattr's *name*, - * not its value -- same class of bug ksmbd_stream_eof() - * (smb2pdu.c) already fixes for EndOfFile/AllocationSize on - * a stream handle; this enumeration path needs the same - * real xattr value length, not the name length reused as a - * size. - */ - slen = ksmbd_vfs_casexattr_len(file_mnt_idmap(fp->filp), - path->dentry, stream_name, - strlen(stream_name) + 1, NULL); + slen = ksmbd_vfs_xattr_len(file_mnt_idmap(fp->filp), + path->dentry, stream_name); ssize = slen < 0 ? 0 : (loff_t)slen; file_info->StreamSize = cpu_to_le64(ssize); file_info->StreamAllocationSize = cpu_to_le64(ssize); diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index 130dd0a4001f2..68781f7a060be 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -950,8 +950,8 @@ ssize_t ksmbd_vfs_listxattr(struct dentry *dentry, char **list) return size; } -static ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap, - struct dentry *dentry, char *xattr_name) +ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap, + struct dentry *dentry, char *xattr_name) { return vfs_getxattr(idmap, dentry, xattr_name, NULL, 0); } diff --git a/fs/smb/server/vfs.h b/fs/smb/server/vfs.h index e9a5798d7baed..ca5048ebb1308 100644 --- a/fs/smb/server/vfs.h +++ b/fs/smb/server/vfs.h @@ -106,6 +106,8 @@ ssize_t ksmbd_vfs_getxattr(struct mnt_idmap *idmap, struct dentry *dentry, char *xattr_name, char **xattr_buf); +ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap, + struct dentry *dentry, char *xattr_name); ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap, struct dentry *dentry, char *attr_name, int attr_name_len, char *actual_name); -- 2.53.0