| Message ID | 20230401063800.342432-1-saravanan.vajravel@broadcom.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [for-rc] RDMA/srpt: Add a check for valid 'mad_agent' pointer | expand |
On Fri, Mar 31, 2023 at 11:38:00PM -0700, Saravanan Vajravel wrote: > 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. Don't fix it like this, don't store err values in global pointers. Jason
> On Fri, Mar 31, 2023 at 11:38:00PM -0700, Saravanan Vajravel wrote: > > 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. > Don't fix it like this, don't store err values in global pointers. Ok. I will re-work on the fix. -Saravanan
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 3c3fae738c3e..07c24182b085 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -634,7 +634,7 @@ static void srpt_unregister_mad_agent(struct srpt_device *sdev, int port_cnt) for (i = 1; i <= port_cnt; i++) { sport = &sdev->port[i - 1]; WARN_ON(sport->port != i); - if (sport->mad_agent) { + if (!IS_ERR_OR_NULL(sport->mad_agent)) { ib_modify_port(sdev->device, i, 0, &port_modify); ib_unregister_mad_agent(sport->mad_agent); sport->mad_agent = NULL;
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> --- drivers/infiniband/ulp/srpt/ib_srpt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)