On 4/8/21 6:26 PM, Eric Dumazet wrote:
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>
Thanks!
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 ?
According to our source copy it looks backported to 1062.7.1, please see:
https://src.openvz.org/projects/OVZ/repos/vzkernel/browse/net/sched/sch_api.c?at=refs%2Ftags%2Frh7-3.10.0-1062.7.1.el7#1167
--
Best regards, Tikhomirov Pavel
Software Developer, Virtuozzo.
