From: Saravanan Vajravel saravanan.vajravel@broadcom.com
[ Upstream commit eca5cd9474cd26d62f9756f536e2e656d3f62f3a ]
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@broadcom.com Reviewed-by: Kashyap Desai kashyap.desai@broadcom.com Signed-off-by: Saravanan Vajravel saravanan.vajravel@broadcom.com Link: https://lore.kernel.org/r/20230406042549.507328-1-saravanan.vajravel@broadco... Reviewed-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/ulp/srpt/ib_srpt.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 3c3fae738c3ed..25e799dba999e 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; @@ -593,24 +594,26 @@ 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); - + return 0; } + + sport->mad_agent = mad_agent; }
return 0;