This is a note to let you know that I've just added the patch titled
ksmbd: validate payload size in ipc response
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ksmbd-validate-payload-size-in-ipc-response.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a677ebd8ca2f2632ccdecbad7b87641274e15aac Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Date: Sun, 31 Mar 2024 21:59:10 +0900
Subject: ksmbd: validate payload size in ipc response
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
commit a677ebd8ca2f2632ccdecbad7b87641274e15aac upstream.
If installing malicious ksmbd-tools, ksmbd.mountd can return invalid ipc
response to ksmbd kernel server. ksmbd should validate payload size of
ipc response from ksmbd.mountd to avoid memory overrun or
slab-out-of-bounds. This patch validate 3 ipc response that has payload.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Chao Ma <machao2019@xxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/smb/server/ksmbd_netlink.h | 3 ++-
fs/smb/server/mgmt/share_config.c | 7 ++++++-
fs/smb/server/transport_ipc.c | 37 +++++++++++++++++++++++++++++++++++++
3 files changed, 45 insertions(+), 2 deletions(-)
--- a/fs/smb/server/ksmbd_netlink.h
+++ b/fs/smb/server/ksmbd_netlink.h
@@ -166,7 +166,8 @@ struct ksmbd_share_config_response {
__u16 force_uid;
__u16 force_gid;
__s8 share_name[KSMBD_REQ_MAX_SHARE_NAME];
- __u32 reserved[112]; /* Reserved room */
+ __u32 reserved[111]; /* Reserved room */
+ __u32 payload_sz;
__u32 veto_list_sz;
__s8 ____payload[];
};
--- a/fs/smb/server/mgmt/share_config.c
+++ b/fs/smb/server/mgmt/share_config.c
@@ -158,7 +158,12 @@ static struct ksmbd_share_config *share_
share->name = kstrdup(name, GFP_KERNEL);
if (!test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) {
- share->path = kstrdup(ksmbd_share_config_path(resp),
+ int path_len = PATH_MAX;
+
+ if (resp->payload_sz)
+ path_len = resp->payload_sz - resp->veto_list_sz;
+
+ share->path = kstrndup(ksmbd_share_config_path(resp), path_len,
GFP_KERNEL);
if (share->path)
share->path_sz = strlen(share->path);
--- a/fs/smb/server/transport_ipc.c
+++ b/fs/smb/server/transport_ipc.c
@@ -65,6 +65,7 @@ struct ipc_msg_table_entry {
struct hlist_node ipc_table_hlist;
void *response;
+ unsigned int msg_sz;
};
static struct delayed_work ipc_timer_work;
@@ -275,6 +276,7 @@ static int handle_response(int type, voi
}
memcpy(entry->response, payload, sz);
+ entry->msg_sz = sz;
wake_up_interruptible(&entry->wait);
ret = 0;
break;
@@ -453,6 +455,34 @@ out:
return ret;
}
+static int ipc_validate_msg(struct ipc_msg_table_entry *entry)
+{
+ unsigned int msg_sz = entry->msg_sz;
+
+ if (entry->type == KSMBD_EVENT_RPC_REQUEST) {
+ struct ksmbd_rpc_command *resp = entry->response;
+
+ msg_sz = sizeof(struct ksmbd_rpc_command) + resp->payload_sz;
+ } else if (entry->type == KSMBD_EVENT_SPNEGO_AUTHEN_REQUEST) {
+ struct ksmbd_spnego_authen_response *resp = entry->response;
+
+ msg_sz = sizeof(struct ksmbd_spnego_authen_response) +
+ resp->session_key_len + resp->spnego_blob_len;
+ } else if (entry->type == KSMBD_EVENT_SHARE_CONFIG_REQUEST) {
+ struct ksmbd_share_config_response *resp = entry->response;
+
+ if (resp->payload_sz) {
+ if (resp->payload_sz < resp->veto_list_sz)
+ return -EINVAL;
+
+ msg_sz = sizeof(struct ksmbd_share_config_response) +
+ resp->payload_sz;
+ }
+ }
+
+ return entry->msg_sz != msg_sz ? -EINVAL : 0;
+}
+
static void *ipc_msg_send_request(struct ksmbd_ipc_msg *msg, unsigned int handle)
{
struct ipc_msg_table_entry entry;
@@ -477,6 +507,13 @@ static void *ipc_msg_send_request(struct
ret = wait_event_interruptible_timeout(entry.wait,
entry.response != NULL,
IPC_WAIT_TIMEOUT);
+ if (entry.response) {
+ ret = ipc_validate_msg(&entry);
+ if (ret) {
+ kvfree(entry.response);
+ entry.response = NULL;
+ }
+ }
out:
down_write(&ipc_msg_table_lock);
hash_del(&entry.ipc_table_hlist);
Patches currently in stable-queue which might be from linkinjeon@xxxxxxxxxx are
queue-6.1/ksmbd-don-t-send-oplock-break-if-rename-fails.patch
queue-6.1/ksmbd-do-not-set-smb2_global_cap_encryption-for-smb-3.1.1.patch
queue-6.1/ksmbd-validate-payload-size-in-ipc-response.patch
