git: e49d57eecc8e - stable/13 - linuxkpi: Handle a NULL cache pointer in kmem_cache_destroy()

The branch stable/13 has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=e49d57eecc8e4cb2247fc667928e91f62d392ca0

commit e49d57eecc8e4cb2247fc667928e91f62d392ca0
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2021-10-06 18:45:22 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2021-10-13 00:36:18 +0000

    linuxkpi: Handle a NULL cache pointer in kmem_cache_destroy()
    
    This is compatible with Linux, and some driver error paths depend on it.
    
    Reviewed by:    bz, emaste
    Sponsored by:   The FreeBSD Foundation
    
    (cherry picked from commit a76de17715ab689b0b53a1012e22d8a08470b6e4)
---
 sys/compat/linuxkpi/common/src/linux_slab.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sys/compat/linuxkpi/common/src/linux_slab.c b/sys/compat/linuxkpi/common/src/linux_slab.c
index 35a88fd7cf42..0aa751ec886e 100644
--- a/sys/compat/linuxkpi/common/src/linux_slab.c
+++ b/sys/compat/linuxkpi/common/src/linux_slab.c
@@ -193,6 +193,9 @@ lkpi_kmem_cache_free(struct linux_kmem_cache *c, void *m)
 void
 linux_kmem_cache_destroy(struct linux_kmem_cache *c)
 {
+	if (c == NULL)
+		return;
+
 	if (unlikely(c->cache_flags & SLAB_TYPESAFE_BY_RCU)) {
 		/* make sure all free callbacks have been called */
 		rcu_barrier();