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* [PATCH 1/3] scsi: libiscsi: move init ehwait to iscsi_session_setup()
@ 2021-09-09 15:47 Ding Hui
2021-09-09 15:47 ` [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset Ding Hui
2021-09-09 15:47 ` [PATCH 3/3] scsi: libiscsi: get ref to conn in iscsi_eh_device/target_reset() Ding Hui
0 siblings, 2 replies; 6+ messages in thread
From: Ding Hui @ 2021-09-09 15:47 UTC (permalink / raw)
To: lduncan, cleech, jejb, michael.christie, open-iscsi, linux-kernel
Cc: Ding Hui
commit ec29d0ac29be ("scsi: iscsi: Fix conn use after free during
resets") move member ehwait from conn to session, but left init ehwait
in iscsi_conn_setup().
Due to one session can be binded by multi conns, the conn after the
first will reinit the session->ehwait, move init ehwait to
iscsi_session_setup() to fix it.
Fixes: ec29d0ac29be ("scsi: iscsi: Fix conn use after free during resets")
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
---
drivers/scsi/libiscsi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 4683c183e9d4..712a45368385 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2947,6 +2947,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
session->tmf_state = TMF_INITIAL;
timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
mutex_init(&session->eh_mutex);
+ init_waitqueue_head(&session->ehwait);
spin_lock_init(&session->frwd_lock);
spin_lock_init(&session->back_lock);
@@ -3074,8 +3075,6 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
goto login_task_data_alloc_fail;
conn->login_task->data = conn->data = data;
- init_waitqueue_head(&session->ehwait);
-
return cls_conn;
login_task_data_alloc_fail:
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset
2021-09-09 15:47 [PATCH 1/3] scsi: libiscsi: move init ehwait to iscsi_session_setup() Ding Hui
@ 2021-09-09 15:47 ` Ding Hui
2021-09-09 15:47 ` [PATCH 3/3] scsi: libiscsi: get ref to conn in iscsi_eh_device/target_reset() Ding Hui
1 sibling, 0 replies; 6+ messages in thread
From: Ding Hui @ 2021-09-09 15:47 UTC (permalink / raw)
To: lduncan, cleech, jejb, michael.christie, open-iscsi, linux-kernel
Cc: Ding Hui
like commit 5db6dd14b313 ("scsi: libiscsi: Fix NULL pointer dereference in
iscsi_eh_session_reset"), access conn->persistent_address here is not safe
too.
The persistent_address is independent of conn refcount, so maybe
already freed by iscsi_conn_teardown(), also we put the refcount of conn
above, the conn pointer may be invalid.
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
---
drivers/scsi/libiscsi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 712a45368385..69b3b2148328 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2531,8 +2531,8 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
spin_lock_bh(&session->frwd_lock);
if (session->state == ISCSI_STATE_LOGGED_IN) {
ISCSI_DBG_EH(session,
- "session reset succeeded for %s,%s\n",
- session->targetname, conn->persistent_address);
+ "session reset succeeded for %s\n",
+ session->targetname);
} else
goto failed;
spin_unlock_bh(&session->frwd_lock);
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/3] scsi: libiscsi: get ref to conn in iscsi_eh_device/target_reset()
2021-09-09 15:47 [PATCH 1/3] scsi: libiscsi: move init ehwait to iscsi_session_setup() Ding Hui
2021-09-09 15:47 ` [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset Ding Hui
@ 2021-09-09 15:47 ` Ding Hui
1 sibling, 0 replies; 6+ messages in thread
From: Ding Hui @ 2021-09-09 15:47 UTC (permalink / raw)
To: lduncan, cleech, jejb, michael.christie, open-iscsi, linux-kernel
Cc: Ding Hui
like commit fda290c5ae98 ("scsi: iscsi: Get ref to conn during reset
handling"), because in iscsi_exec_task_mgmt_fn(), the eh_mutex and
frwd_lock will be unlock, the conn also can be released if we not
hold ref.
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
---
drivers/scsi/libiscsi.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 69b3b2148328..4d3b37c20f8a 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2398,7 +2398,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
- struct iscsi_conn *conn;
+ struct iscsi_conn *conn = NULL;
struct iscsi_tm *hdr;
int rc = FAILED;
@@ -2417,6 +2417,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
goto unlock;
conn = session->leadconn;
+ iscsi_get_conn(conn->cls_conn);
/* only have one tmf outstanding at a time */
if (session->tmf_state != TMF_INITIAL)
@@ -2463,6 +2464,8 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
done:
ISCSI_DBG_EH(session, "dev reset result = %s\n",
rc == SUCCESS ? "SUCCESS" : "FAILED");
+ if (conn)
+ iscsi_put_conn(conn->cls_conn);
mutex_unlock(&session->eh_mutex);
return rc;
}
@@ -2560,7 +2563,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
- struct iscsi_conn *conn;
+ struct iscsi_conn *conn = NULL;
struct iscsi_tm *hdr;
int rc = FAILED;
@@ -2579,6 +2582,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
goto unlock;
conn = session->leadconn;
+ iscsi_get_conn(conn->cls_conn);
/* only have one tmf outstanding at a time */
if (session->tmf_state != TMF_INITIAL)
@@ -2625,6 +2629,8 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
done:
ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
rc == SUCCESS ? "SUCCESS" : "FAILED");
+ if (conn)
+ iscsi_put_conn(conn->cls_conn);
mutex_unlock(&session->eh_mutex);
return rc;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RESEND] [PATCH 0/3] fix several bugs about libiscsi
@ 2021-09-10 1:02 Ding Hui
2021-09-10 1:02 ` [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset Ding Hui
0 siblings, 1 reply; 6+ messages in thread
From: Ding Hui @ 2021-09-10 1:02 UTC (permalink / raw)
To: lduncan, cleech, jejb, martin.petersen, michael.christie,
open-iscsi, linux-scsi, linux-kernel
Cc: Ding Hui
Ding Hui (3):
scsi: libiscsi: move init ehwait to iscsi_session_setup()
scsi: libiscsi: fix invalid pointer dereference in
iscsi_eh_session_reset
scsi: libiscsi: get ref to conn in iscsi_eh_device/target_reset()
drivers/scsi/libiscsi.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset
2021-09-10 1:02 [RESEND] [PATCH 0/3] fix several bugs about libiscsi Ding Hui
@ 2021-09-10 1:02 ` Ding Hui
2021-09-10 16:38 ` Mike Christie
0 siblings, 1 reply; 6+ messages in thread
From: Ding Hui @ 2021-09-10 1:02 UTC (permalink / raw)
To: lduncan, cleech, jejb, martin.petersen, michael.christie,
open-iscsi, linux-scsi, linux-kernel
Cc: Ding Hui
like commit 5db6dd14b313 ("scsi: libiscsi: Fix NULL pointer dereference in
iscsi_eh_session_reset"), access conn->persistent_address here is not safe
too.
The persistent_address is independent of conn refcount, so maybe
already freed by iscsi_conn_teardown(), also we put the refcount of conn
above, the conn pointer may be invalid.
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
---
drivers/scsi/libiscsi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 712a45368385..69b3b2148328 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2531,8 +2531,8 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
spin_lock_bh(&session->frwd_lock);
if (session->state == ISCSI_STATE_LOGGED_IN) {
ISCSI_DBG_EH(session,
- "session reset succeeded for %s,%s\n",
- session->targetname, conn->persistent_address);
+ "session reset succeeded for %s\n",
+ session->targetname);
} else
goto failed;
spin_unlock_bh(&session->frwd_lock);
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset
2021-09-10 1:02 ` [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset Ding Hui
@ 2021-09-10 16:38 ` Mike Christie
2021-09-11 9:52 ` Ding Hui
0 siblings, 1 reply; 6+ messages in thread
From: Mike Christie @ 2021-09-10 16:38 UTC (permalink / raw)
To: Ding Hui, lduncan, cleech, jejb, martin.petersen, open-iscsi,
linux-scsi, linux-kernel
On 9/9/21 8:02 PM, Ding Hui wrote:
> like commit 5db6dd14b313 ("scsi: libiscsi: Fix NULL pointer dereference in
> iscsi_eh_session_reset"), access conn->persistent_address here is not safe
> too.
>
> The persistent_address is independent of conn refcount, so maybe
> already freed by iscsi_conn_teardown(), also we put the refcount of conn
> above, the conn pointer may be invalid.
This shouldn't happen like you describe above, because when we wake up
we will see the session->state is ISCSI_STATE_TERMINATE. We will then
not reference the conn in that code below.
However, it looks like we could hit an issue where if a user was resetting
the persistent_address or targetname via iscsi_set_param -> iscsi_switch_str_param
then we could be accessing freed memory. I think we need the frwd_lock when swapping
the strings in iscsi_switch_str_param.
>
> Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
> ---
> drivers/scsi/libiscsi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
> index 712a45368385..69b3b2148328 100644
> --- a/drivers/scsi/libiscsi.c
> +++ b/drivers/scsi/libiscsi.c
> @@ -2531,8 +2531,8 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
> spin_lock_bh(&session->frwd_lock);
> if (session->state == ISCSI_STATE_LOGGED_IN) {
> ISCSI_DBG_EH(session,
> - "session reset succeeded for %s,%s\n",
> - session->targetname, conn->persistent_address);
> + "session reset succeeded for %s\n",
> + session->targetname);
> } else
> goto failed;
> spin_unlock_bh(&session->frwd_lock);
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset
2021-09-10 16:38 ` Mike Christie
@ 2021-09-11 9:52 ` Ding Hui
0 siblings, 0 replies; 6+ messages in thread
From: Ding Hui @ 2021-09-11 9:52 UTC (permalink / raw)
To: Mike Christie, lduncan, cleech, jejb, martin.petersen,
open-iscsi, linux-scsi, linux-kernel
On 2021/9/11 12:38 上午, Mike Christie wrote:
> On 9/9/21 8:02 PM, Ding Hui wrote:
>> like commit 5db6dd14b313 ("scsi: libiscsi: Fix NULL pointer dereference in
>> iscsi_eh_session_reset"), access conn->persistent_address here is not safe
>> too.
>>
>> The persistent_address is independent of conn refcount, so maybe
>> already freed by iscsi_conn_teardown(), also we put the refcount of conn
>> above, the conn pointer may be invalid.
>
> This shouldn't happen like you describe above, because when we wake up
> we will see the session->state is ISCSI_STATE_TERMINATE. We will then
> not reference the conn in that code below.
>
> However, it looks like we could hit an issue where if a user was resetting
> the persistent_address or targetname via iscsi_set_param -> iscsi_switch_str_param
> then we could be accessing freed memory. I think we need the frwd_lock when swapping
> the strings in iscsi_switch_str_param.
>
Thanks for your detailed explanation, I'll drop 2/3 and 3/3 in v2 patch.
I expect that the persistent_address issue be fixed in your future patchset.
Sorry for my ignorance.
>
>>
>> Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
>> ---
>> drivers/scsi/libiscsi.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
>> index 712a45368385..69b3b2148328 100644
>> --- a/drivers/scsi/libiscsi.c
>> +++ b/drivers/scsi/libiscsi.c
>> @@ -2531,8 +2531,8 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
>> spin_lock_bh(&session->frwd_lock);
>> if (session->state == ISCSI_STATE_LOGGED_IN) {
>> ISCSI_DBG_EH(session,
>> - "session reset succeeded for %s,%s\n",
>> - session->targetname, conn->persistent_address);
>> + "session reset succeeded for %s\n",
>> + session->targetname);
>> } else
>> goto failed;
>> spin_unlock_bh(&session->frwd_lock);
>>
>
--
Thanks,
-dinghui
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-09-11 9:52 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-09 15:47 [PATCH 1/3] scsi: libiscsi: move init ehwait to iscsi_session_setup() Ding Hui
2021-09-09 15:47 ` [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset Ding Hui
2021-09-09 15:47 ` [PATCH 3/3] scsi: libiscsi: get ref to conn in iscsi_eh_device/target_reset() Ding Hui
2021-09-10 1:02 [RESEND] [PATCH 0/3] fix several bugs about libiscsi Ding Hui
2021-09-10 1:02 ` [PATCH 2/3] scsi: libiscsi: fix invalid pointer dereference in iscsi_eh_session_reset Ding Hui
2021-09-10 16:38 ` Mike Christie
2021-09-11 9:52 ` Ding Hui
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