ksmbd: Fix ZDI-CAN-18259

This fixes a security problem in ksmbd. It currently has the
ZDI-CAN-18259 ID assigned, but no CVE yet.

Backported from:
8824b7af40
cc4f3b5a6a

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

package/kernel/ksmbd/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ksmbd
 PKG_VERSION:=3.4.6
-PKG_RELEASE:=$(AUTORELEASE)
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://codeload.github.com/cifsd-team/cifsd/tar.gz/$(PKG_VERSION)?

package/kernel/ksmbd/patches/10-ksmbd-check-nt_len-to-be-at-least-CIFS_ENCPWD_SIZE-i.patch

@@ -0,0 +1,36 @@
+From 8824b7af409f51f1316e92e9887c2fd48c0b26d6 Mon Sep 17 00:00:00 2001
+From: William Liu <will@willsroot.io>
+Date: Fri, 30 Dec 2022 09:13:35 +0900
+Subject: ksmbd: check nt_len to be at least CIFS_ENCPWD_SIZE in
+ ksmbd_decode_ntlmssp_auth_blob
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+"nt_len - CIFS_ENCPWD_SIZE" is passed directly from
+ksmbd_decode_ntlmssp_auth_blob to ksmbd_auth_ntlmv2. Malicious requests
+can set nt_len to less than CIFS_ENCPWD_SIZE, which results in a negative
+number (or large unsigned value) used for a subsequent memcpy in
+ksmbd_auth_ntlvm2 and can cause a panic.
+
+Fixes: e2f3448 ("cifsd: add server-side procedures for SMB3")
+Cc: stable@vger.kernel.org
+Signed-off-by: William Liu <will@willsroot.io>
+Signed-off-by: Hrvoje Mišetić <misetichrvoje@gmail.com>
+Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
+---
+ auth.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/auth.c
++++ b/auth.c
+@@ -583,7 +583,8 @@ int ksmbd_decode_ntlmssp_auth_blob(struc
+ 	dn_off = le32_to_cpu(authblob->DomainName.BufferOffset);
+ 	dn_len = le16_to_cpu(authblob->DomainName.Length);
+ 
+-	if (blob_len < (u64)dn_off + dn_len || blob_len < (u64)nt_off + nt_len)
++	if (blob_len < (u64)dn_off + dn_len || blob_len < (u64)nt_off + nt_len ||
++	    nt_len < CIFS_ENCPWD_SIZE)
+ 		return -EINVAL;
+ 
+ #ifdef CONFIG_SMB_INSECURE_SERVER

package/kernel/ksmbd/patches/11-ksmbd-fix-infinite-loop-in-ksmbd_conn_handler_loop.patch

@@ -0,0 +1,63 @@
+From cc4f3b5a6ab4693aba94a45cc073188df4d67175 Mon Sep 17 00:00:00 2001
+From: Namjae Jeon <linkinjeon@kernel.org>
+Date: Mon, 26 Dec 2022 01:28:52 +0900
+Subject: ksmbd: fix infinite loop in ksmbd_conn_handler_loop()
+
+If kernel_recvmsg() return -EAGAIN in ksmbd_tcp_readv() and go round
+again, It will cause infinite loop issue. And all threads from next
+connections would be doing that. This patch add max retry count(2) to
+avoid it. kernel_recvmsg() will wait during 7sec timeout and try to
+retry two time if -EAGAIN is returned. And add flags of kvmalloc to
+__GFP_NOWARN and __GFP_NORETRY to disconnect immediately without
+retrying on memory alloation failure.
+
+Fixes: 0626e66 ("cifsd: add server handler for central processing and tranport layers")
+Cc: stable@vger.kernel.org
+Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-18259
+Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
+Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
+---
+ connection.c    | 7 +++++--
+ transport_tcp.c | 5 ++++-
+ 2 files changed, 9 insertions(+), 3 deletions(-)
+
+--- a/connection.c
++++ b/connection.c
+@@ -337,9 +337,12 @@ int ksmbd_conn_handler_loop(void *p)
+ 
+ 		/* 4 for rfc1002 length field */
+ 		size = pdu_size + 4;
+-		conn->request_buf = kvmalloc(size, GFP_KERNEL);
++		conn->request_buf = kvmalloc(size,
++					     GFP_KERNEL |
++					     __GFP_NOWARN |
++					     __GFP_NORETRY);
+ 		if (!conn->request_buf)
+-			continue;
++			break;
+ 
+ 		memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
+ 		if (!ksmbd_smb_request(conn))
+--- a/transport_tcp.c
++++ b/transport_tcp.c
+@@ -323,6 +323,7 @@ static int ksmbd_tcp_readv(struct tcp_tr
+ 	struct msghdr ksmbd_msg;
+ 	struct kvec *iov;
+ 	struct ksmbd_conn *conn = KSMBD_TRANS(t)->conn;
++	int max_retry = 2;
+ 
+ 	iov = get_conn_iovec(t, nr_segs);
+ 	if (!iov)
+@@ -349,9 +350,11 @@ static int ksmbd_tcp_readv(struct tcp_tr
+ 		} else if (conn->status == KSMBD_SESS_NEED_RECONNECT) {
+ 			total_read = -EAGAIN;
+ 			break;
+-		} else if (length == -ERESTARTSYS || length == -EAGAIN) {
++		} else if ((length == -ERESTARTSYS || length == -EAGAIN) &&
++			   max_retry) {
+ 			usleep_range(1000, 2000);
+ 			length = 0;
++			max_retry--;
+ 			continue;
+ 		} else if (length <= 0) {
+ 			total_read = -EAGAIN;