git: bfa89a5dd105 - stable/12 - iflib: fix potential NULL dereference

[Kristof Provost]

The branch stable/12 has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=bfa89a5dd1055447ee64e0a4cf77898ee970a3b1

commit bfa89a5dd1055447ee64e0a4cf77898ee970a3b1
Author:     Kristof Provost <kp at FreeBSD.org>
AuthorDate: 2021-08-31 12:11:22 +0000
Commit:     Kristof Provost <kp at FreeBSD.org>
CommitDate: 2021-08-31 19:12:50 +0000

    iflib: fix potential NULL dereference
    
    iflib_softirq_alloc_generic() can be called with a NULL irq parameter
    (as done by for example the bnxt and ixl drivers). If
    iflib_irq_set_affinity() then returns an error we'd try to dereference
    the NULL irq pointer.
    
    Check irq, and pass '-1' (which taskqgroup_attach() expects) if we don't
    have an irq.
    
    Direct commit to stable/12, because this issue does not exist on main
    and stable/13.
    
    Reviewed by:    kbowling
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
    Differential Revision:  https://reviews.freebsd.org/D31758
---
 sys/net/iflib.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/net/iflib.c b/sys/net/iflib.c
index 8dc1715e625d..f8d4c120b3ec 100644
--- a/sys/net/iflib.c
+++ b/sys/net/iflib.c
@@ -6200,7 +6200,7 @@ iflib_irq_set_affinity(if_ctx_t ctx, if_irq_t irq, iflib_intr_type_t type,
 	base_cpuid = ctx->ifc_sysctl_core_offset;
 	cpuid = get_cpuid_for_queue(ctx, base_cpuid, qid, type == IFLIB_INTR_TX);
 	err = taskqgroup_attach_cpu(tqg, gtask, uniq, cpuid,
-	    rman_get_start(irq->ii_res), name);
+	    irq ? rman_get_start(irq->ii_res) : -1, name);
 	if (err) {
 		device_printf(dev, "taskqgroup_attach_cpu failed %d\n", err);
 		return (err);
@@ -6337,7 +6337,7 @@ iflib_softirq_alloc_generic(if_ctx_t ctx, if_irq_t irq, iflib_intr_type_t type,
 	err = iflib_irq_set_affinity(ctx, irq, type, qid, gtask, tqg, q, name);
 	if (err) {
 		dev = ctx->ifc_dev;
-		taskqgroup_attach(tqg, gtask, q, rman_get_start(irq->ii_res),
+		taskqgroup_attach(tqg, gtask, q, irq ? rman_get_start(irq->ii_res) : -1,
 		    name);
 	}
 }