kernel/linux.git/net/sched/act_api.c, branch v6.6.131

net: use unrcu_pointer() helper

2024-12-09T09:32:10+00:00

[ Upstream commit b4cb4a1391dcdc640c4ade003aaf0ee19cc8d509 ] Toke mentioned unrcu_pointer() existence, allowing to remove some of the ugly casts we have when using xchg() for rcu protected pointers. Also make inet_rcv_compat const. Signed-off-by: Eric Dumazet Cc: Toke Høiland-Jørgensen Reviewed-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20240604111603.45871-1-edumazet@google.com Signed-off-by: Paolo Abeni Stable-dep-of: eb02688c5c45 ("ipv6: release nexthop on device removal") Signed-off-by: Sasha Levin

net/sched: act_api: deny mismatched skip_sw/skip_hw flags for actions created by classifiers

2024-11-01T00:58:30+00:00

[ Upstream commit 34d35b4edbbe890a91bec939bfd29ad92517a52b ] tcf_action_init() has logic for checking mismatches between action and filter offload flags (skip_sw/skip_hw). AFAIU, this is intended to run on the transition between the new tc_act_bind(flags) returning true (aka now gets bound to classifier) and tc_act_bind(act->tcfa_flags) returning false (aka action was not bound to classifier before). Otherwise, the check is skipped. For the case where an action is not standalone, but rather it was created by a classifier and is bound to it, tcf_action_init() skips the check entirely, and this means it allows mismatched flags to occur. Taking the matchall classifier code path as an example (with mirred as an action), the reason is the following: 1 | mall_change() 2 | -> mall_replace_hw_filter() 3 | -> tcf_exts_validate_ex() 4 | -> flags |= TCA_ACT_FLAGS_BIND; 5 | -> tcf_action_init() 6 | -> tcf_action_init_1() 7 | -> a_o->init() 8 | -> tcf_mirred_init() 9 | -> tcf_idr_create_from_flags() 10 | -> tcf_idr_create() 11 | -> p->tcfa_flags = flags; 12 | -> tc_act_bind(flags)) 13 | -> tc_act_bind(act->tcfa_flags) When invoked from tcf_exts_validate_ex() like matchall does (but other classifiers validate their extensions as well), tcf_action_init() runs in a call path where "flags" always contains TCA_ACT_FLAGS_BIND (set by line 4). So line 12 is always true, and line 13 is always true as well. No transition ever takes place, and the check is skipped. The code was added in this form in commit c86e0209dc77 ("flow_offload: validate flags of filter and actions"), but I'm attributing the blame even earlier in that series, to when TCA_ACT_FLAGS_SKIP_HW and TCA_ACT_FLAGS_SKIP_SW were added to the UAPI. Following the development process of this change, the check did not always exist in this form. A change took place between v3 [1] and v4 [2], AFAIU due to review feedback that it doesn't make sense for action flags to be different than classifier flags. I think I agree with that feedback, but it was translated into code that omits enforcing this for "classic" actions created at the same time with the filters themselves. There are 3 more important cases to discuss. First there is this command: $ tc qdisc add dev eth0 clasct $ tc filter add dev eth0 ingress matchall skip_sw \ action mirred ingress mirror dev eth1 which should be allowed, because prior to the concept of dedicated action flags, it used to work and it used to mean the action inherited the skip_sw/skip_hw flags from the classifier. It's not a mismatch. Then we have this command: $ tc qdisc add dev eth0 clasct $ tc filter add dev eth0 ingress matchall skip_sw \ action mirred ingress mirror dev eth1 skip_hw where there is a mismatch and it should be rejected. Finally, we have: $ tc qdisc add dev eth0 clasct $ tc filter add dev eth0 ingress matchall skip_sw \ action mirred ingress mirror dev eth1 skip_sw where the offload flags coincide, and this should be treated the same as the first command based on inheritance, and accepted. [1]: https://lore.kernel.org/netdev/20211028110646.13791-9-simon.horman@corigine.com/ [2]: https://lore.kernel.org/netdev/20211118130805.23897-10-simon.horman@corigine.com/ Fixes: 7adc57651211 ("flow_offload: add skip_hw and skip_sw to control if offload the action") Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Link: https://patch.msgid.link/20241017161049.3570037-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc()

2024-06-27T11:49:07+00:00

[ Upstream commit d864319871b05fadd153e0aede4811ca7008f5d6 ] syzbot found hanging tasks waiting on rtnl_lock [1] A reproducer is available in the syzbot bug. When a request to add multiple actions with the same index is sent, the second request will block forever on the first request. This holds rtnl_lock, and causes tasks to hang. Return -EAGAIN to prevent infinite looping, while keeping documented behavior. [1] INFO: task kworker/1:0:5088 blocked for more than 143 seconds. Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 wiphy_lock include/net/cfg80211.h:5953 [inline] reg_leave_invalid_chans net/wireless/reg.c:2466 [inline] reg_check_chans_work+0x10a/0x10e0 net/wireless/reg.c:2481 Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action") Reported-by: syzbot+b87c222546179f4513a7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b87c222546179f4513a7 Signed-off-by: David Ruth Reviewed-by: Jamal Hadi Salim Link: https://lore.kernel.org/r/20240614190326.1349786-1-druth@chromium.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/sched: act_api: rely on rcu in tcf_idr_check_alloc

2024-06-27T11:49:07+00:00

[ Upstream commit 4b55e86736d5b492cf689125da2600f59c7d2c39 ] Instead of relying only on the idrinfo->lock mutex for bind/alloc logic, rely on a combination of rcu + mutex + atomics to better scale the case where multiple rtnl-less filters are binding to the same action object. Action binding happens when an action index is specified explicitly and an action exists which such index exists. Example: tc actions add action drop index 1 tc filter add ... matchall action drop index 1 tc filter add ... matchall action drop index 1 tc filter add ... matchall action drop index 1 tc filter ls ... filter protocol all pref 49150 matchall chain 0 filter protocol all pref 49150 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 filter protocol all pref 49151 matchall chain 0 filter protocol all pref 49151 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 filter protocol all pref 49152 matchall chain 0 filter protocol all pref 49152 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 When no index is specified, as before, grab the mutex and allocate in the idr the next available id. In this version, as opposed to before, it's simplified to store the -EBUSY pointer instead of the previous alloc + replace combination. When an index is specified, rely on rcu to find if there's an object in such index. If there's none, fallback to the above, serializing on the mutex and reserving the specified id. If there's one, it can be an -EBUSY pointer, in which case we just try again until it's an action, or an action. Given the rcu guarantees, the action found could be dead and therefore we need to bump the refcount if it's not 0, handling the case it's in fact 0. As bind and the action refcount are already atomics, these increments can happen without the mutex protection while many tcf_idr_check_alloc race to bind to the same action instance. In case binding encounters a parallel delete or add, it will return -EAGAIN in order to try again. Both filter and action apis already have the retry machinery in-place. In case it's an unlocked filter it retries under the rtnl lock. Signed-off-by: Pedro Tammela Acked-by: Jamal Hadi Salim Reviewed-by: Vlad Buslov Link: https://lore.kernel.org/r/20231211181807.96028-2-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski Stable-dep-of: d864319871b0 ("net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc()") Signed-off-by: Sasha Levin

net: sched: Replace strlcpy with strscpy

2023-07-10T07:23:53+00:00

strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). Direct replacement is safe here since return value of -errno is used to check for truncation instead of sizeof(dest). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh Reviewed-by: Pavan Chebbi Signed-off-by: David S. Miller

net/sched: act_api: use the correct TCA_ACT attributes in dump

2023-03-23T08:39:08+00:00

4 places in the act api code are using 'TCA_' definitions where they should be using 'TCA_ACT_', which is confusing for the reader, although functionally they are equivalent. Cc: Hangbin Liu Reviewed-by: Jamal Hadi Salim Reviewed-by: Simon Horman Signed-off-by: Pedro Tammela Acked-by: Hangbin Liu Signed-off-by: David S. Miller

net/sched: act_api: add specific EXT_WARN_MSG for tc action

2023-03-17T04:25:45+00:00

In my previous commit 0349b8779cc9 ("sched: add new attr TCA_EXT_WARN_MSG to report tc extact message") I didn't notice the tc action use different enum with filter. So we can't use TCA_EXT_WARN_MSG directly for tc action. Let's add a TCA_ROOT_EXT_WARN_MSG for tc action specifically and put this param before going to the TCA_ACT_TAB nest. Fixes: 0349b8779cc9 ("sched: add new attr TCA_EXT_WARN_MSG to report tc extact message") Signed-off-by: Hangbin Liu Acked-by: Jamal Hadi Salim Signed-off-by: Jakub Kicinski

Revert "net/sched: act_api: move TCA_EXT_WARN_MSG to the correct hierarchy"

2023-03-17T04:25:45+00:00

This reverts commit 923b2e30dc9cd05931da0f64e2e23d040865c035. This is not a correct fix as TCA_EXT_WARN_MSG is not a hierarchy to TCA_ACT_TAB. I didn't notice the TC actions use different enum when adding TCA_EXT_WARN_MSG. To fix the difference I will add a new WARN enum in TCA_ROOT_MAX as Jamal suggested. Signed-off-by: Hangbin Liu Acked-by: Jamal Hadi Salim Signed-off-by: Jakub Kicinski

net/sched: act_api: move TCA_EXT_WARN_MSG to the correct hierarchy

2023-02-27T12:16:34+00:00

TCA_EXT_WARN_MSG is currently sitting outside of the expected hierarchy for the tc actions code. It should sit within TCA_ACT_TAB. Fixes: 0349b8779cc9 ("sched: add new attr TCA_EXT_WARN_MSG to report tc extact message") Reviewed-by: Jamal Hadi Salim Signed-off-by: Pedro Tammela Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net/sched: cls_api: Support hardware miss to tc action

2023-02-21T00:46:10+00:00

For drivers to support partial offload of a filter's action list, add support for action miss to specify an action instance to continue from in sw. CT action in particular can't be fully offloaded, as new connections need to be handled in software. This imposes other limitations on the actions that can be offloaded together with the CT action, such as packet modifications. Assign each action on a filter's action list a unique miss_cookie which drivers can then use to fill action_miss part of the tc skb extension. On getting back this miss_cookie, find the action instance with relevant cookie and continue classifying from there. Signed-off-by: Paul Blakey Reviewed-by: Jiri Pirko Reviewed-by: Simon Horman Reviewed-by: Marcelo Ricardo Leitner Acked-by: Jamal Hadi Salim Signed-off-by: Jakub Kicinski