From f2f11fca5d7112e2f91c4854cddd68a059fdaa4a Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Tue, 19 Sep 2023 23:19:29 +0900 Subject: ksmbd: return invalid parameter error response if smb2 request is invalid If smb2 request from client is invalid, The following kernel oops could happen. The patch e2b76ab8b5c9: "ksmbd: add support for read compound" leads this issue. When request is invalid, It doesn't set anything in the response buffer. This patch add missing set invalid parameter error response. [ 673.085542] ksmbd: cli req too short, len 184 not 142. cmd:5 mid:109 [ 673.085580] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 673.085591] #PF: supervisor read access in kernel mode [ 673.085600] #PF: error_code(0x0000) - not-present page [ 673.085608] PGD 0 P4D 0 [ 673.085620] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 673.085631] CPU: 3 PID: 1039 Comm: kworker/3:0 Not tainted 6.6.0-rc2-tmt #16 [ 673.085643] Hardware name: AZW U59/U59, BIOS JTKT001 05/05/2022 [ 673.085651] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd] [ 673.085719] RIP: 0010:ksmbd_conn_write+0x68/0xc0 [ksmbd] [ 673.085808] RAX: 0000000000000000 RBX: ffff88811ade4f00 RCX: 0000000000000000 [ 673.085817] RDX: 0000000000000000 RSI: ffff88810c2a9780 RDI: ffff88810c2a9ac0 [ 673.085826] RBP: ffffc900005e3e00 R08: 0000000000000000 R09: 0000000000000000 [ 673.085834] R10: ffffffffa3168160 R11: 63203a64626d736b R12: ffff8881057c8800 [ 673.085842] R13: ffff8881057c8820 R14: ffff8882781b2380 R15: ffff8881057c8800 [ 673.085852] FS: 0000000000000000(0000) GS:ffff888278180000(0000) knlGS:0000000000000000 [ 673.085864] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 673.085872] CR2: 0000000000000000 CR3: 000000015b63c000 CR4: 0000000000350ee0 [ 673.085883] Call Trace: [ 673.085890] [ 673.085900] ? show_regs+0x6a/0x80 [ 673.085916] ? __die+0x25/0x70 [ 673.085926] ? page_fault_oops+0x154/0x4b0 [ 673.085938] ? tick_nohz_tick_stopped+0x18/0x50 [ 673.085954] ? __irq_work_queue_local+0xba/0x140 [ 673.085967] ? do_user_addr_fault+0x30f/0x6c0 [ 673.085979] ? exc_page_fault+0x79/0x180 [ 673.085992] ? asm_exc_page_fault+0x27/0x30 [ 673.086009] ? ksmbd_conn_write+0x68/0xc0 [ksmbd] [ 673.086067] ? ksmbd_conn_write+0x46/0xc0 [ksmbd] [ 673.086123] handle_ksmbd_work+0x28d/0x4b0 [ksmbd] [ 673.086177] process_one_work+0x178/0x350 [ 673.086193] ? __pfx_worker_thread+0x10/0x10 [ 673.086202] worker_thread+0x2f3/0x420 [ 673.086210] ? _raw_spin_unlock_irqrestore+0x27/0x50 [ 673.086222] ? __pfx_worker_thread+0x10/0x10 [ 673.086230] kthread+0x103/0x140 [ 673.086242] ? __pfx_kthread+0x10/0x10 [ 673.086253] ret_from_fork+0x39/0x60 [ 673.086263] ? __pfx_kthread+0x10/0x10 [ 673.086274] ret_from_fork_asm+0x1b/0x30 Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound") Reported-by: Tom Talpey Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/server.c | 4 +++- fs/smb/server/smb2misc.c | 4 +--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c index 5ab2f52f9b35..32347fec33c4 100644 --- a/fs/smb/server/server.c +++ b/fs/smb/server/server.c @@ -115,8 +115,10 @@ static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn, if (check_conn_state(work)) return SERVER_HANDLER_CONTINUE; - if (ksmbd_verify_smb_message(work)) + if (ksmbd_verify_smb_message(work)) { + conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); return SERVER_HANDLER_ABORT; + } command = conn->ops->get_cmd_val(work); *cmd = command; diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c index e881df1d10cb..23bd3d1209df 100644 --- a/fs/smb/server/smb2misc.c +++ b/fs/smb/server/smb2misc.c @@ -440,10 +440,8 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work) validate_credit: if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && - smb2_validate_credit_charge(work->conn, hdr)) { - work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); + smb2_validate_credit_charge(work->conn, hdr)) return 1; - } return 0; } -- cgit v1.2.3-70-g09d2 From 73f949ea87c7d697210653501ca21efe57295327 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Thu, 21 Sep 2023 15:37:06 +0900 Subject: ksmbd: check iov vector index in ksmbd_conn_write() If ->iov_idx is zero, This means that the iov vector for the response was not added during the request process. In other words, it means that there is a problem in generating a response, So this patch return as an error to avoid NULL pointer dereferencing problem. Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/connection.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c index 0d990c2f33cd..db7fa704a3f6 100644 --- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -197,6 +197,9 @@ int ksmbd_conn_write(struct ksmbd_work *work) if (work->send_no_response) return 0; + if (!work->iov_idx) + return -EINVAL; + ksmbd_conn_lock(conn); sent = conn->transport->ops->writev(conn->transport, work->iov, work->iov_cnt, -- cgit v1.2.3-70-g09d2