From: Ben Hutchings <ben@decadent.org.uk> stable inclusion from stable-v4.19.286 commit 53f16fa73f71abfcac67e71a5513653b8db28b76 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7J5UF CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 7c5d4801ecf0564c860033d89726b99723c55146 ] irq_cpu_rmap_release() calls cpu_rmap_put(), which may free the rmap. So we need to clear the pointer to our glue structure in rmap before doing that, not after. Fixes: 4e0473f1060a ("lib: cpu_rmap: Avoid use after free on rmap->obj array entries") Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/ZHo0vwquhOy3FaXc@decadent.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Guo Mengqi <guomengqi3@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- lib/cpu_rmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/cpu_rmap.c b/lib/cpu_rmap.c index f52389054a24..a0de1b2579f7 100644 --- a/lib/cpu_rmap.c +++ b/lib/cpu_rmap.c @@ -271,8 +271,8 @@ static void irq_cpu_rmap_release(struct kref *ref) struct irq_glue *glue = container_of(ref, struct irq_glue, notify.kref); - cpu_rmap_put(glue->rmap); glue->rmap->obj[glue->index] = NULL; + cpu_rmap_put(glue->rmap); kfree(glue); } -- 2.25.1