When unregistering MAD agent, srpt module has a non-null check
for 'mad_agent' pointer before invoking ib_unregister_mad_agent().
This check can pass if 'mad_agent' variable holds an error value.
The 'mad_agent' can have an error value for a short window when
srpt_add_one() and srpt_remove_one() is executed simultaneously.
In srpt module, added a valid pointer check for 'sport->mad_agent'
before unregistering MAD agent.
This issue can hit when RoCE driver unregisters ib_device
Stack Trace:
------------
BUG: kernel NULL pointer dereference, address: 000000000000004d
PGD 145003067 P4D 145003067 PUD 2324fe067 PMD 0
Oops: 0002 [#1] PREEMPT SMP NOPTI
CPU: 10 PID: 4459 Comm: kworker/u80:0 Kdump: loaded Tainted: P
Hardware name: Dell Inc. PowerEdge R640/06NR82, BIOS 2.5.4 01/13/2020
Workqueue: bnxt_re bnxt_re_task [bnxt_re]
RIP: 0010:_raw_spin_lock_irqsave+0x19/0x40
Call Trace:
ib_unregister_mad_agent+0x46/0x2f0 [ib_core]
IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
? __schedule+0x20b/0x560
srpt_unregister_mad_agent+0x93/0xd0 [ib_srpt]
srpt_remove_one+0x20/0x150 [ib_srpt]
remove_client_context+0x88/0xd0 [ib_core]
bond0: (slave p2p1): link status definitely up, 100000 Mbps full duplex
disable_device+0x8a/0x160 [ib_core]
bond0: active interface up!
? kernfs_name_hash+0x12/0x80
(NULL device *): Bonding Info Received: rdev: 000000006c0b8247
__ib_unregister_device+0x42/0xb0 [ib_core]
(NULL device *): Master: mode: 4 num_slaves:2
ib_unregister_device+0x22/0x30 [ib_core]
(NULL device *): Slave: id: 105069936 name:p2p1 link:0 state:0
bnxt_re_stopqps_and_ib_uninit+0x83/0x90 [bnxt_re]
bnxt_re_alloc_lag+0x12e/0x4e0 [bnxt_re]
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Reviewed-by: Selvin Xavier <selvin.xavier@xxxxxxxxxxxx>
Reviewed-by: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx>
Signed-off-by: Saravanan Vajravel <saravanan.vajravel@xxxxxxxxxxxx>
---
v1->v2:
- Return pointer of mad_agent is stored in local pointer to verify
if it is successfully registered
drivers/infiniband/ulp/srpt/ib_srpt.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 3c3fae738c3e..b4cb88563bb2 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -549,6 +549,7 @@ static int srpt_format_guid(char *buf, unsigned int size, const __be64 *guid)
*/
static int srpt_refresh_port(struct srpt_port *sport)
{
+ struct ib_mad_agent *mad_agent;
struct ib_mad_reg_req reg_req;
struct ib_port_modify port_modify;
struct ib_port_attr port_attr;
@@ -593,23 +594,24 @@ static int srpt_refresh_port(struct srpt_port *sport)
set_bit(IB_MGMT_METHOD_GET, reg_req.method_mask);
set_bit(IB_MGMT_METHOD_SET, reg_req.method_mask);
- sport->mad_agent = ib_register_mad_agent(sport->sdev->device,
- sport->port,
- IB_QPT_GSI,
- ®_req, 0,
- srpt_mad_send_handler,
- srpt_mad_recv_handler,
- sport, 0);
- if (IS_ERR(sport->mad_agent)) {
+ mad_agent = ib_register_mad_agent(sport->sdev->device,
+ sport->port,
+ IB_QPT_GSI,
+ ®_req, 0,
+ srpt_mad_send_handler,
+ srpt_mad_recv_handler,
+ sport, 0);
+ if (IS_ERR(mad_agent)) {
pr_err("%s-%d: MAD agent registration failed (%ld). Note: this is expected if SR-IOV is enabled.\n",
dev_name(&sport->sdev->device->dev), sport->port,
- PTR_ERR(sport->mad_agent));
+ PTR_ERR(mad_agent));
sport->mad_agent = NULL;
memset(&port_modify, 0, sizeof(port_modify));
port_modify.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
ib_modify_port(sport->sdev->device, sport->port, 0,
&port_modify);
-
+ } else {
+ sport->mad_agent = mad_agent;
}
}
--
2.31.1
Attachment:
smime.p7s
Description: S/MIME Cryptographic Signature
