From: Javed Hasan <jhasan@xxxxxxxxxxx> [ Upstream commit 73578af92a0fae6609b955fcc9113e50e413c80f ] The following trace was observed: [ 14.042059] Call Trace: [ 14.042061] <IRQ> [ 14.042068] qedf_link_update+0x144/0x1f0 [qedf] [ 14.042117] qed_link_update+0x5c/0x80 [qed] [ 14.042135] qed_mcp_handle_link_change+0x2d2/0x410 [qed] [ 14.042155] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042170] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042186] ? qed_rd+0x13/0x40 [qed] [ 14.042205] qed_mcp_handle_events+0x437/0x690 [qed] [ 14.042221] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042239] qed_int_sp_dpc+0x3a6/0x3e0 [qed] [ 14.042245] tasklet_action_common.isra.14+0x5a/0x100 [ 14.042250] __do_softirq+0xe4/0x2f8 [ 14.042253] irq_exit+0xf7/0x100 [ 14.042255] do_IRQ+0x7f/0xd0 [ 14.042257] common_interrupt+0xf/0xf [ 14.042259] </IRQ> API qedf_link_update() is getting called from QED but by that time shost_data is not initialised. This results in a NULL pointer dereference when we try to dereference shost_data while updating supported_speeds. Add a NULL pointer check before dereferencing shost_data. Link: https://lore.kernel.org/r/20210512072533.23618-1-jhasan@xxxxxxxxxxx Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.") Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx> Signed-off-by: Javed Hasan <jhasan@xxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/qedf/qedf_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/qedf/qedf_main.c b/drivers/scsi/qedf/qedf_main.c index 46d185cb9ea8..a464d0a4f465 100644 --- a/drivers/scsi/qedf/qedf_main.c +++ b/drivers/scsi/qedf/qedf_main.c @@ -536,7 +536,9 @@ static void qedf_update_link_speed(struct qedf_ctx *qedf, if (linkmode_intersects(link->supported_caps, sup_caps)) lport->link_supported_speeds |= FC_PORTSPEED_20GBIT; - fc_host_supported_speeds(lport->host) = lport->link_supported_speeds; + if (lport->host && lport->host->shost_data) + fc_host_supported_speeds(lport->host) = + lport->link_supported_speeds; } static void qedf_bw_update(void *dev) -- 2.30.2
