iscsi_sw_tcp_conn_set_param should check the pointer before using it.
I got this ops when starting my os:
[ 27.158355] sd 27:0:0:1: [sdco] Mode Sense: 83 00 00 08
[ 27.158377] scsi 27:0:0:3: Direct-Access ZBS VOLUME 0000 PQ: 0 ANSI: 5
[ 27.167665] connection39:0: detected conn error (1020)
[ 27.174681] BUG: kernel NULL pointer dereference, address: 0000000000000020
[ 27.174706] #PF: supervisor read access in kernel mode
[ 27.174719] #PF: error_code(0x0000) - not-present page
[ 27.174731] PGD 0 P4D 0
[ 27.174739] Oops: 0000 [#1] SMP NOPTI
[ 27.174749] CPU: 8 PID: 1044 Comm: iscsid Not tainted 5.11.12-300.fc34.x86_64 #1
[ 27.174767] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018
[ 27.174790] RIP: 0010:iscsi_sw_tcp_conn_set_param+0x6a/0x80 [iscsi_tcp]
[ 27.174807] Code: 85 d2 74 23 48 89 83 e0 00 00 00 31 c0 5b 5d c3 e8 bb 21 fb ff 31 c0 5b 5d c3 48 89 ef 5b 48 89 d6 5d e9 99 62 ff ff 48 8b 03 <48> 8b 40 20 48 8b 80 a0 00 00 00 eb cd 66 0f 1f 84 00 00 00 00 00
[ 27.174847] RSP: 0018:ffffba8a46103b90 EFLAGS: 00010246
[ 27.174860] RAX: 0000000000000000 RBX: ffff98cbf22766b8 RCX: ffffffffc096d6b9
[ 27.174877] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff98cbdbcb6049
[ 27.174893] RBP: ffff98cbf2276348 R08: 00000000000000ff R09: 000000000000000a
[ 27.174909] R10: 000000000000000a R11: f000000000000000 R12: ffff98cbdbcb6010
[ 27.174925] R13: ffff98cbdbcb6048 R14: ffff98cbf2279800 R15: 0000000000000414
[ 27.174941] FS: 00007fa88bab7cc0(0000) GS:ffff98d1e0000000(0000) knlGS:0000000000000000
[ 27.175188] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 27.175441] CR2: 0000000000000020 CR3: 000000022522c000 CR4: 00000000003506e0
[ 27.175734] Call Trace:
[ 27.176003] iscsi_if_rx+0xdda/0x1adc [scsi_transport_iscsi]
[ 27.176291] ? __kmalloc_node_track_caller+0xec/0x280
[ 27.176585] ? netlink_sendmsg+0x30c/0x440
[ 27.176880] netlink_unicast+0x1d3/0x2a0
[ 27.177191] netlink_sendmsg+0x22a/0x440
[ 27.177494] sock_sendmsg+0x5e/0x60
[ 27.177799] ____sys_sendmsg+0x22c/0x270
[ 27.178107] ? import_iovec+0x17/0x20
[ 27.178422] ? sendmsg_copy_msghdr+0x59/0x90
[ 27.178747] ? _copy_from_user+0x3c/0x80
[ 27.179072] ___sys_sendmsg+0x81/0xc0
[ 27.179402] ? ___sys_recvmsg+0x86/0xe0
[ 27.179736] ? handle_mm_fault+0x113f/0x1970
[ 27.180076] ? enqueue_hrtimer+0x32/0x70
[ 27.180422] __sys_sendmsg+0x49/0x80
[ 27.180778] do_syscall_64+0x33/0x40
[ 27.181132] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Signed-off-by: Li Feng <[email protected]>
---
drivers/scsi/iscsi_tcp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 1bc37593c88f..2ec1405d272d 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -724,6 +724,8 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
break;
case ISCSI_PARAM_DATADGST_EN:
iscsi_set_param(cls_conn, param, buf, buflen);
+ if (!tcp_sw_conn || !tcp_sw_conn->sock)
+ return -ENOTCONN;
tcp_sw_conn->sendpage = conn->datadgst_en ?
sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
break;
--
2.31.1
On 10/10/21 2:19 AM, Li Feng wrote:
> drivers/scsi/iscsi_tcp.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> index 1bc37593c88f..2ec1405d272d 100644
> --- a/drivers/scsi/iscsi_tcp.c
> +++ b/drivers/scsi/iscsi_tcp.c
> @@ -724,6 +724,8 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
> break;
> case ISCSI_PARAM_DATADGST_EN:
> iscsi_set_param(cls_conn, param, buf, buflen);
> + if (!tcp_sw_conn || !tcp_sw_conn->sock)
> + return -ENOTCONN;
> tcp_sw_conn->sendpage = conn->datadgst_en ?
> sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
> break;
>
Hi,
Thanks for the patch. This was supposed to be fixed in:
commit 9e67600ed6b8565da4b85698ec659b5879a6c1c6
Author: Gulam Mohamed <[email protected]>
Date: Thu Mar 25 09:32:48 2021 +0000
scsi: iscsi: Fix race condition between login and sync thread
because it was not supposed to allow set_param to be called on
an unbound connection. However, it looks like there was a mistake in
the patch:
err = transport->set_param(conn, ev->u.set_param.param,
data, ev->u.set_param.len);
+ if ((conn->state == ISCSI_CONN_BOUND) ||
+ (conn->state == ISCSI_CONN_UP)) {
+ err = transport->set_param(conn, ev->u.set_param.param,
+ data, ev->u.set_param.len);
+ } else {
+ return -ENOTCONN;
+ }
and that first set_param call was supposed to be deleted and
replaced with the one that was added in the conn->state check.
We should just need a patch to remove that first set_param call.
Thanks,
Feng Li
<[email protected]> 于2021年10月11日周一 上午12:05写道：
>
> On 10/10/21 2:19 AM, Li Feng wrote:
> > drivers/scsi/iscsi_tcp.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> > index 1bc37593c88f..2ec1405d272d 100644
> > --- a/drivers/scsi/iscsi_tcp.c
> > +++ b/drivers/scsi/iscsi_tcp.c
> > @@ -724,6 +724,8 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
> > break;
> > case ISCSI_PARAM_DATADGST_EN:
> > iscsi_set_param(cls_conn, param, buf, buflen);
> > + if (!tcp_sw_conn || !tcp_sw_conn->sock)
> > + return -ENOTCONN;
> > tcp_sw_conn->sendpage = conn->datadgst_en ?
> > sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
> > break;
> >
>
> Hi,
>
> Thanks for the patch. This was supposed to be fixed in:
>
> commit 9e67600ed6b8565da4b85698ec659b5879a6c1c6
> Author: Gulam Mohamed <[email protected]>
> Date: Thu Mar 25 09:32:48 2021 +0000
>
> scsi: iscsi: Fix race condition between login and sync thread
>
> because it was not supposed to allow set_param to be called on
> an unbound connection. However, it looks like there was a mistake in
> the patch:
>
> err = transport->set_param(conn, ev->u.set_param.param,
> data, ev->u.set_param.len);
> + if ((conn->state == ISCSI_CONN_BOUND) ||
> + (conn->state == ISCSI_CONN_UP)) {
> + err = transport->set_param(conn, ev->u.set_param.param,
> + data, ev->u.set_param.len);
> + } else {
> + return -ENOTCONN;
> + }
>
>
> and that first set_param call was supposed to be deleted and
> replaced with the one that was added in the conn->state check.
>
> We should just need a patch to remove that first set_param call.
Yes, I have checked the upstream code, this is an obvious mistake here.
I encountered this issue on 5.11.12-300.fc34.x86_64, it doesn't
include this patch,
so I check the pointer like my patch.
Thanks.