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] <TASK>
[ 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 <tom@xxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
---
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;
}
--
2.25.1
