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=1793735328; b=OHtTdcfk574lP6CRgoEI8IWKEL4KZxN2ifUclihSTzU39VtDRegzO7tUFn3HPhvyUZr1 L5nZgH6Nc1iDghccIcj7kZKrv+J0X0JhlHa+ebykU/8Pbtl48nxCau3RRkwhrx/vFcGxG Gw3Va8ncPqexUAzyF9dURtB6OA8Z9i8JC43aqkl2iuFnkcwglXYPI0tjcxGhiNZ3/JyEY YRPXpg8Lkm/bT4OI6W12ettkhkm9Me3QqtzuSmHv1DLGNpHjfroc8AxUMETIxna1pV9Mq H+6urys1Rf6AQY/NjzO2EwzKWbPSF0GOa3LYSceGJ0JkPNSmgsZRGvOURSOMcxa79zA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793735328; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=Tanm8huoLVBnPKJ5qp+Yu3eTl9Ar/d+jV6fB0qmWj/Y=; b=vchU+a8m3Sk8RmX35FO74rl7MSlQrzBoiWCsw1rjc6U16yDymuxqk9/n6ObJH/i3tRyB yDb916PQl8kkAmlgsxMS7YHFmoL38VxXheLm75nT0eBJsF3dh+umWGx9BbTGMY4yKF8B8 VGrV0Mug0jmxCAzYtrjV3CtTIq6AAhSMzR+DzouS3NE93rLWqcfH+k/Vvh+W7hNullP2X aYW5/6bEuLFJVHs8UGVVMeqVhR5AP5FATin0yYbwcuYI4lI5W3g0xuzZv6+5v4k15ax64 PG7ELR6TMQpXFsJuTokphOye90AxBFC0oZ562xOLTSToBxpKcB+ePg46zgN7bmRgu7g== 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=bvzHH8UO; 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 896AF606A33B for ; Tue, 3 Nov 2026 19:48:48 +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=bvzHH8UO Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BA4B1F000C1; Tue, 3 Nov 2026 19:48:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793735328; bh=Tanm8huoLVBnPKJ5qp+Yu3eTl9Ar/d+jV6fB0qmWj/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bvzHH8UOdZI6gX6iP53aOiiGIXO3O1MhV4lhO6aNgCpVZteWyJtsQ6ANGyolB5HCr PbHL8Ae+ykWVES5yqpUbZanHg78BrnfBL9DyRqgaY5d4N/G1i+XXVv8yVj/jVMwFgY 19vlNYSWA54lW5lcF2Ob21BCCu4vb1orWF2pqL4RBAL7Zz5CIRQdHmmzTQ73/uCJdm lF0JkAAnKCbwFPG4QBQ+RC7fknY6HrOiMgzRAQn8s6M1Zzp09cCRqfwOzxk3jH3MYM ygGlu/BKqZU7fJbNtPkwQTwHr/uunofIZV93dvvDeRMhNee/BL1KrEV6zfzaf8VzGl pPQ/F8J6JPvRQ== From: Sasha Levin To: stable@vger.kernel.org Cc: DaeMyung Kang , Namjae Jeon , Sasha Levin Subject: [PATCH 6.18.y] ksmbd: use the existing xattr name for a named stream Date: Tue, 3 Nov 2026 14:48:46 -0500 Message-ID: <20261103194749.1035677-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110358-jaywalker-relapse-2135@gregkh> References: <2026110358-jaywalker-relapse-2135@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: DaeMyung Kang [ Upstream commit a7d1d52748e0fe4d06fdb871fc9899904fbba93f ] SMB stream names are case-insensitive, but ksmbd stores each named stream in an xattr whose name is case-sensitive. Opening an existing stream finds its xattr with a case-insensitive match, yet the handle keeps the name as the client spelled it, and every later operation that needs an exact name uses that spelling: - a WRITE or an end-of-file change creates a second xattr, so a stream created as "Foo" and written through "foo" ends up stored twice, and which value a later lookup returns depends on xattr list order; - delete-on-close and delete-pending removal can fail with -ENODATA, or remove only a case-variant copy and leave the original; - the share mode check compares stream names with strcmp(), so two opens of the same stream that differ only in case do not conflict. Have ksmbd_vfs_casexattr_len() copy the matching xattr's name into the handle when the stream is opened, so later operations use the name already on disk. The match must have the same length as the name it replaces; the stream lookup passes a length that includes the terminating NUL, which already guarantees that, and the check makes the copy safe for any caller. A stream that does not exist yet keeps the client's spelling, as before. smb2_rename() compares and looks up fp->stream.name case-insensitively, so it behaves the same with either spelling. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: DaeMyung Kang Signed-off-by: Namjae Jeon [ sashal: adapted stream lookup signature changes to the existing callers and non-const mnt_idmap interface ] Signed-off-by: Sasha Levin --- fs/smb/server/smb2pdu.c | 8 ++++---- fs/smb/server/vfs.c | 7 ++++++- fs/smb/server/vfs.h | 2 +- 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 793c219b9a610..9af1ef5a13d6a 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2464,7 +2464,7 @@ static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len, path->dentry, attr_name, XATTR_USER_PREFIX_LEN + - eabuf->EaNameLength); + eabuf->EaNameLength, NULL); /* delete the EA only when it exits */ if (rc > 0) { @@ -2536,11 +2536,11 @@ static noinline int smb2_set_stream_name_xattr(const struct path *path, fp->stream.name = xattr_stream_name; fp->stream.size = xattr_stream_size; - /* Check if there is stream prefix in xattr space */ + /* Keep the existing xattr's case for subsequent writes and removal. */ rc = ksmbd_vfs_casexattr_len(idmap, path->dentry, xattr_stream_name, - xattr_stream_size); + xattr_stream_size, xattr_stream_name); if (rc >= 0) return 0; if (rc != -ENOENT && rc != -ENODATA) @@ -5243,7 +5243,7 @@ static int get_file_stream_info(struct ksmbd_work *work, */ slen = ksmbd_vfs_casexattr_len(file_mnt_idmap(fp->filp), path->dentry, stream_name, - strlen(stream_name) + 1); + strlen(stream_name) + 1, NULL); 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 c18ab8431e0d2..b23179a7b780c 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -1812,7 +1812,7 @@ int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work, ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap, struct dentry *dentry, char *attr_name, - int attr_name_len) + int attr_name_len, char *actual_name) { char *name, *xattr_list = NULL; ssize_t value_len = -ENOENT, xattr_list_len; @@ -1830,8 +1830,13 @@ ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap, ksmbd_debug(VFS, "%s, len %zd\n", name, strlen(name)); if (strncasecmp(attr_name, name, attr_name_len)) continue; + if (actual_name && strlen(name) + 1 != attr_name_len) + continue; value_len = ksmbd_vfs_xattr_len(idmap, dentry, name); + /* The caller provides attr_name_len bytes for the actual name. */ + if (value_len >= 0 && actual_name) + memcpy(actual_name, name, attr_name_len); break; } diff --git a/fs/smb/server/vfs.h b/fs/smb/server/vfs.h index df6421b4590ba..ccf289592718c 100644 --- a/fs/smb/server/vfs.h +++ b/fs/smb/server/vfs.h @@ -107,7 +107,7 @@ ssize_t ksmbd_vfs_getxattr(struct mnt_idmap *idmap, char **xattr_buf); ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap, struct dentry *dentry, char *attr_name, - int attr_name_len); + int attr_name_len, char *actual_name); int ksmbd_vfs_setxattr(struct mnt_idmap *idmap, const struct path *path, const char *attr_name, void *attr_value, size_t attr_size, int flags, -- 2.53.0