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=1794590015; b=yl5H1rwqJ0BLx5t+fNqoNr5vayt0wcXITg9n8IsroM6m/a319F6AE7zCa81dTaeyP2uV KE3U6QAiLfHq7d1H6uri3K6FBU9Y3fqszAeqcXvm06nRVjhVcu7LLcuNR4SW3n0oXBcjk qBCBPag26ET/j6bRSIAd+EryY+R9JTvlWiMqLDGvhWdivE1PMF2qAhZgHFgv1zEKIAK02 Y8HGhQ4v1tVvPi+D1woXDQVkr3uPHCeNZz4RcM9YOtXxjEFB/n9UE7/XReVmc0+l4RFC2 xAXYaXQd57DF12/UdVAo9GjKK/4IBM7aW2TORDjAMZCiaOBN7bM/QJRv8dPbvpKPuhA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590015; 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=RZ4vxl75737Gu4SIFaKh4VW8JMlpcZm7DJvO10DviMs=; b=uwB+mnadVMwnpQb6m/KrxTQ+j0fQ/uqecAk5JSHE8oPKSKKONhhBFFxugVD8yKQ7lfMN 7aXLAC9/CQkTT8EaxlreisLHq7vPjth77REzJmCHkXNc4oODkPaBB90M5au5hrBiEXthH W7opxVfp2HpCl+eMZB7Ic4urpBeXKIbhUYApN7GXAQ14Pyr9jyuVjFLuNybzO2hBA8ihu sG7sUG7ouPSEr66lV4xUV8o3dqK/W3ACqi3b0U3vJp/dxNQhD5FZc3pXuS3YUNuJhIybv yJLBFkh1vDO7O6i1GTu7sLJEPfP14PUjF3mDSyPXbr5beaiRIK2qer+VrJ3yGQHFy6w== 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=TCHa+l7X; 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 25005606A331; Fri, 13 Nov 2026 17:13:35 +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=TCHa+l7X Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7A5D1F000C4; Fri, 13 Nov 2026 17:13:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590014; bh=RZ4vxl75737Gu4SIFaKh4VW8JMlpcZm7DJvO10DviMs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TCHa+l7XugJgP5ZZoLXr73y4RaCWEGviVW9ETV2lCIe+1EpMHLmNsfDVmTDViYNSr KvMjss0HKuuG/ncZQRaxlabWsS9TSG+mZ1tVgcMKbQnvAlAE1IwNP6fdo5REck7/oW YT7yfakx9QJ2zWgYkQGliR47ZmT4hYSQB2ETB/Bg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gael Blivet , Namjae Jeon , Sasha Levin Subject: [PATCH 6.18 057/686] ksmbd: look up stream size by exact xattr name Date: Fri, 13 Nov 2026 10:43:10 -0500 Message-ID: <20261113153822.882205118@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 c784aa6d9b6ad..1cbc425d7273e 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 c470d419e7ce8..a3db77b3c2728 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