On Thu, Jan 02, 2020 at 01:31:22PM +0530, Naresh Kamboju wrote:
On Fri, 27 Dec 2019 at 23:17, Sasha Levin <sashal@xxxxxxxxxx> wrote:From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40 ] Michal Kubecek and Firo Yang did a very nice analysis of crashes happening in __inet_lookup_established(). Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN (via a close()/socket()/listen() cycle) without a RCU grace period, I should not have changed listeners linkage in their hash table. They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt), so that a lookup can detect a socket in a hash list was moved in another one. Since we added code in commit d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix"), we have to add hlist_nulls_add_tail_rcu() helper.The kernel panic reported on all devices, While running LTP syscalls accept* test cases on stable-rc-4.19 branch kernel. This report log extracted from qemu_x86_64. Reverting this patch re-solved kernel crash.
I'll drop it until we can look into what's happening here, thanks! -- Thanks, Sasha
