From: Lijun Pan <ljp@xxxxxxxxxxxxx> [ Upstream commit a0faaa27c71608799e0dd765c5af38a089091802 ] adapter->tx_scrq and adapter->rx_scrq could be NULL if the previous reset did not complete after freeing sub crqs. Check for NULL before dereferencing them. Snippet of call trace: ibmvnic 30000006 env6: Releasing sub-CRQ ibmvnic 30000006 env6: Releasing CRQ ... ibmvnic 30000006 env6: Got Control IP offload Response ibmvnic 30000006 env6: Re-setting tx_scrq[0] BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc008000003dea7cc Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag tun bridge stp llc rfkill sunrpc pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmvnic ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod CPU: 80 PID: 1856 Comm: kworker/80:2 Tainted: G W 5.8.0+ #4 Workqueue: events __ibmvnic_reset [ibmvnic] NIP: c008000003dea7cc LR: c008000003dea7bc CTR: 0000000000000000 REGS: c0000007ef7db860 TRAP: 0380 Tainted: G W (5.8.0+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28002422 XER: 0000000d CFAR: c000000000bd9520 IRQMASK: 0 GPR00: c008000003dea7bc c0000007ef7dbaf0 c008000003df7400 c0000007fa26ec00 GPR04: c0000007fcd0d008 c0000007fcd96350 0000000000000027 c0000007fcd0d010 GPR08: 0000000000000023 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000002000 c00000001ec18e00 c0000000001982f8 c0000007bad6e840 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 fffffffffffffef7 GPR24: 0000000000000402 c0000007fa26f3a8 0000000000000003 c00000016f8ec048 GPR28: 0000000000000000 0000000000000000 0000000000000000 c0000007fa26ec00 NIP [c008000003dea7cc] ibmvnic_reset_init+0x15c/0x258 [ibmvnic] LR [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic] Call Trace: [c0000007ef7dbaf0] [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic] (unreliable) [c0000007ef7dbb80] [c008000003de8860] __ibmvnic_reset+0x408/0x970 [ibmvnic] [c0000007ef7dbc50] [c00000000018b7cc] process_one_work+0x2cc/0x800 [c0000007ef7dbd20] [c00000000018bd78] worker_thread+0x78/0x520 [c0000007ef7dbdb0] [c0000000001984c4] kthread+0x1d4/0x1e0 [c0000007ef7dbe20] [c00000000000cea8] ret_from_kernel_thread+0x5c/0x74 Fixes: 57a49436f4e8 ("ibmvnic: Reset sub-crqs during driver reset") Signed-off-by: Lijun Pan <ljp@xxxxxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/ibm/ibmvnic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 0341089743ff1..349d0b3d9edc3 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2887,6 +2887,9 @@ static int reset_sub_crq_queues(struct ibmvnic_adapter *adapter) { int i, rc; + if (!adapter->tx_scrq || !adapter->rx_scrq) + return -EINVAL; + for (i = 0; i < adapter->req_tx_queues; i++) { netdev_dbg(adapter->netdev, "Re-setting tx_scrq[%d]\n", i); rc = reset_one_sub_crq_queue(adapter, adapter->tx_scrq[i]); -- 2.27.0