On 4/8/21 5:14 PM, Pavel Tikhomirov wrote:
> Reproduce:
>
> modprobe sch_teql
> tc qdisc add dev teql0 root teql0
>
> This leads to (for instance in Centos 7 VM) OOPS:
>
>
>
> Null pointer dereference happens on master->slaves dereference in
> teql_destroy() as master is null-pointer.
>
> When qdisc_create() calls teql_qdisc_init() it imediately fails after
> check "if (m->dev == dev)" because both devices are teql0, and it does
> not set qdisc_priv(sch)->m leaving it zero on error path, then
> qdisc_create() imediately calls teql_destroy() which does not expect
> zero master pointer and we get OOPS.
>
> Signed-off-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com>
> ---
This makes sense, thanks !
Reviewed-by: Eric Dumazet <eduma...@google.com>
I would think bug origin is
Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation")
Can you confirm you have this backported to 3.10.0-1062.7.1.el7.x86_64 ?
