The patch titled Subject: kernel/taskstats: fix wrong nla type for {cgroup,task}stats policy has been added to the -mm tree. Its filename is kernel-taskstats-fix-wrong-nla-type-for-cgrouptaskstats-policy.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/kernel-taskstats-fix-wrong-nla-type-for-cgrouptaskstats-policy.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/kernel-taskstats-fix-wrong-nla-type-for-cgrouptaskstats-policy.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Yafang Shao <laoar.shao@xxxxxxxxx> Subject: kernel/taskstats: fix wrong nla type for {cgroup,task}stats policy After our server is upgraded to a newer kernel, we found that it continuesly print a warning in the kernel message. The warning is, [832984.946322] netlink: 'irmas.lc': attribute type 1 has an invalid length. irmas.lc is one of our container monitor daemons, and it will use CGROUPSTATS_CMD_GET to get the cgroupstats, that is similar with tools/accounting/getdelays.c. We can also produce this warning with getdelays. For example, after running bellow command $ ./getdelays -C /sys/fs/cgroup/memory then you can find a warning in dmesg, [61607.229318] netlink: 'getdelays': attribute type 1 has an invalid length. This warning is introduced in commit 6e237d099fac ("netlink: Relax attr validation for fixed length types"), which is used to check whether attributes using types NLA_U* and NLA_S* have an exact length. Regarding this issue, the root cause is cgroupstats_cmd_get_policy defines a wrong type as NLA_U32, while it should be NLA_NESTED an its minimal length is NLA_HDRLEN. That is similar to taskstats_cmd_get_policy. As this behavior change really breaks our application, we'd better cc stable as well. Link: http://lkml.kernel.org/r/1585191042-9935-1-git-send-email-laoar.shao@xxxxxxxxx Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> Cc: Balbir Singh <bsingharora@xxxxxxxxx> Cc: David Ahern <dsahern@xxxxxxxxx> Cc: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/taskstats.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/kernel/taskstats.c~kernel-taskstats-fix-wrong-nla-type-for-cgrouptaskstats-policy +++ a/kernel/taskstats.c @@ -35,8 +35,8 @@ struct kmem_cache *taskstats_cache; static struct genl_family family; static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = { - [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, - [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, + [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_NESTED }, + [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_NESTED }, [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },}; @@ -45,7 +45,7 @@ static const struct nla_policy taskstats * Make sure they are always aligned. */ static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = { - [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 }, + [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_NESTED }, }; struct listener { _ Patches currently in -mm which might be from laoar.shao@xxxxxxxxx are kernel-taskstats-fix-wrong-nla-type-for-cgrouptaskstats-policy.patch mm-memcg-fix-build-error-around-the-usage-of-kmem_caches.patch