There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Refactor the code according to the use of a flexible-array member in
struct tc_u_hnode and use the struct_size() helper to calculate the
size for the allocations. Commit 5778d39d07 ("net_sched: fix struct
tc_u_hnode layout in u32") makes it clear that the code is expected to
dynamically allocate divisor + 1 entries for ->ht[] in tc_uhnode. Also,
based on other observations, as the piece of code below:
1232 for (h = 0; h <= ht->divisor; h++) {
1233 for (n = rtnl_dereference(ht->ht[h]);
1234 n;
1235 n = rtnl_dereference(n->next)) {
1236 if (tc_skip_hw(n->flags))
1237 continue;
1238
1239 err = u32_reoffload_knode(tp, n, add, cb,
1240 cb_priv, extack);
1241 if (err)
1242 return err;
1243 }
1244 }
we can assume that, in general, the code is actually expecting to allocate
that extra space for the one-element array in tc_uhnode, everytime it
allocates memory for instances of tc_uhnode or tc_u_common structures.
That's the reason for passing '1' as the last argument for struct_size()
in the allocation for _root_ht_ and _tp_c_, and 'divisor + 1' in the
allocation code for _ht_.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays
Tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/5f7062af.z3T9tn9yIPv6h5Ny%25lkp@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make use of the struct_size() helper, in multiple places, instead
of an open-coded version in order to avoid any potential type
mistakes and protect against potential integer overflows.
Also, remove unnecessary object identifier size.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
This code was detected with the help of Coccinelle and, audited and
fixed manually.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current implementations of ops->bind_class() are merely
searching for classid and updating class in the struct tcf_result,
without invoking either of cl_ops->bind_tcf() or
cl_ops->unbind_tcf(). This breaks the design of them as qdisc's
like cbq use them to count filters too. This is why syzbot triggered
the warning in cbq_destroy_class().
In order to fix this, we have to call cl_ops->bind_tcf() and
cl_ops->unbind_tcf() like the filter binding path. This patch does
so by refactoring out two helper functions __tcf_bind_filter()
and __tcf_unbind_filter(), which are lockless and accept a Qdisc
pointer, then teaching each implementation to call them correctly.
Note, we merely pass the Qdisc pointer as an opaque pointer to
each filter, they only need to pass it down to the helper
functions without understanding it at all.
Fixes: 07d79fc7d9 ("net_sched: add reverse binding for tc class")
Reported-and-tested-by: syzbot+0a0596220218fcb603a8@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+63bdb6006961d8c917c6@syzkaller.appspotmail.com
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Revert "net/sched: cls_u32: fix refcount leak in the error path of
u32_change()", and fix the u32 refcount leak in a more generic way that
preserves the semantic of rule dumping.
On tc filters that don't support lockless insertion/removal, there is no
need to guard against concurrent insertion when a removal is in progress.
Therefore, for most of them we can avoid a full walk() when deleting, and
just decrease the refcount, like it was done on older Linux kernels.
This fixes situations where walk() was wrongly detecting a non-empty
filter, like it happened with cls_u32 in the error path of change(), thus
leading to failures in the following tdc selftests:
6aa7: (filter, u32) Add/Replace u32 with source match and invalid indev
6658: (filter, u32) Add/Replace u32 with custom hash table and invalid handle
74c2: (filter, u32) Add/Replace u32 filter with invalid hash table id
On cls_flower, and on (future) lockless filters, this check is necessary:
move all the check_empty() logic in a callback so that each filter
can have its own implementation. For cls_flower, it's sufficient to check
if no IDRs have been allocated.
This reverts commit 275c44aa19.
Changes since v1:
- document the need for delete_empty() when TCF_PROTO_OPS_DOIT_UNLOCKED
is used, thanks to Vlad Buslov
- implement delete_empty() without doing fl_walk(), thanks to Vlad Buslov
- squash revert and new fix in a single patch, to be nice with bisect
tests that run tdc on u32 filter, thanks to Dave Miller
Fixes: 275c44aa19 ("net/sched: cls_u32: fix refcount leak in the error path of u32_change()")
Fixes: 6676d5e416 ("net: sched: set dedicated tcf_walker flag when tp is empty")
Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Suggested-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
when users replace cls_u32 filters with new ones having wrong parameters,
so that u32_change() fails to validate them, the kernel doesn't roll-back
correctly, and leaves semi-configured rules.
Fix this in u32_walk(), avoiding a call to the walker function on filters
that don't have a match rule connected. The side effect is, these "empty"
filters are not even dumped when present; but that shouldn't be a problem
as long as we are restoring the original behaviour, where semi-configured
filters were not even added in the error path of u32_change().
Fixes: 6676d5e416 ("net: sched: set dedicated tcf_walker flag when tp is empty")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without rtnl lock protection filters can no longer safely manage block
offloads counter themselves. Refactor cls API to protect block offloadcnt
with tcf_block->cb_lock that is already used to protect driver callback
list and nooffloaddevcnt counter. The counter can be modified by concurrent
tasks by new functions that execute block callbacks (which is safe with
previous patch that changed its type to atomic_t), however, block
bind/unbind code that checks the counter value takes cb_lock in write mode
to exclude any concurrent modifications. This approach prevents race
conditions between bind/unbind and callback execution code but allows for
concurrency for tc rule update path.
Move block offload counter, filter in hardware counter and filter flags
management from classifiers into cls hardware offloads API. Make functions
tcf_block_offload_{inc|dec}() and tc_cls_offload_cnt_update() to be cls API
private. Implement following new cls API to be used instead:
tc_setup_cb_add() - non-destructive filter add. If filter that wasn't
already in hardware is successfully offloaded, increment block offloads
counter, set filter in hardware counter and flag. On failure, previously
offloaded filter is considered to be intact and offloads counter is not
decremented.
tc_setup_cb_replace() - destructive filter replace. Release existing
filter block offload counter and reset its in hardware counter and flag.
Set new filter in hardware counter and flag. On failure, previously
offloaded filter is considered to be destroyed and offload counter is
decremented.
tc_setup_cb_destroy() - filter destroy. Unconditionally decrement block
offloads counter.
tc_setup_cb_reoffload() - reoffload filter to single cb. Execute cb() and
call tc_cls_offload_cnt_update() if cb() didn't return an error.
Refactor all offload-capable classifiers to atomically offload filters to
hardware, change block offload counter, and set filter in hardware counter
and flag by means of the new cls API functions.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename this type definition and adapt users.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This config option makes only couple of lines optional.
Two small helpers and an int in couple of cls structs.
Remove the config option and always compile this in.
This saves the user from unexpected surprises when he adds
a filter with ingress device match which is silently ignored
in case the config option is not set.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on feedback from Jiri avoid carrying a pointer to the tcf_block
structure in the tc_cls_common_offload structure. Instead store
a flag in driver private data which indicates if offloads apply
to a shared block at block binding time.
Suggested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some actions like the police action are stateful and could share state
between devices. This is incompatible with offloading to multiple devices
and drivers might want to test for shared blocks when offloading.
Store a pointer to the tcf_block structure in the tc_cls_common_offload
structure to allow drivers to determine when offloads apply to a shared
block.
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.
So, replace code of the following form:
sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key)
with:
struct_size(s, keys, s->nkeys)
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.
Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().
Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:
@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)
@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For tcindex filter, it is too late to initialize the
net pointer in tcf_exts_validate(), as tcf_exts_get_net()
requires a non-NULL net pointer. We can just move its
initialization into tcf_exts_init(), which just requires
an additional parameter.
This makes the code in tcindex_alloc_perfect_hash()
prettier.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add 'rtnl_held' flag to tcf proto change, delete, destroy, dump, walk
functions to track rtnl lock status. Extend users of these function in cls
API to propagate rtnl lock status to them. This allows classifiers to
obtain rtnl lock when necessary and to pass rtnl lock status to extensions
and driver offload callbacks.
Add flags field to tcf proto ops. Add flag value to indicate that
classifier doesn't require rtnl lock.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Actions API is already updated to not rely on rtnl lock for
synchronization. However, it need to be provided with rtnl status when
called from classifiers API in order to be able to correctly release the
lock when loading kernel module.
Extend extension validation function with 'rtnl_held' flag which is passed
to actions API. Add new 'rtnl_held' parameter to tcf_exts_validate() in cls
API. No classifier is currently updated to support unlocked execution, so
pass hardcoded 'true' flag parameter value.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 69bd48404f ("net/sched: Remove egdev mechanism"),
tc_setup_cb_call() is nearly identical to tcf_block_cb_call(),
so we can just fold tcf_block_cb_call() into tc_setup_cb_call()
and remove its unused parameter 'exts'.
Fixes: 69bd48404f ("net/sched: Remove egdev mechanism")
Cc: Oz Shlomo <ozsh@mellanox.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Oz Shlomo <ozsh@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case of egress offloads the class/flowid assigned by the filter
may be very important for offloaded Qdisc selection. Provide this
info to drivers.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we have the knode count, we can instantly check if
any hnodes are non-empty. And that kills the check for extra
references to root hnode - those could happen only if there was
a knode to carry such a link.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
allows to simplify u32_delete() considerably
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both hnode ->tp_c and tp_c argument of u32_set_parms()
the latter is redundant, the former - never read...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It must be tc_u_common associated with that tp (i.e. tp->data).
Proof:
* both ->ht_up and ->tp_c are assign-once
* ->tp_c of anything inserted into tp_c->hlist is tp_c
* hnodes never get reinserted into the lists or moved
between those, so anything found by u32_lookup_ht(tp->data, ...)
will have ->tp_c equal to tp->data.
* tp->root->tp_c == tp->data.
* ->ht_up of anything inserted into hnode->ht[...] is
equal to hnode.
* knodes never get reinserted into hash chains or moved
between those, so anything returned by u32_lookup_key(ht, ...)
will have ->ht_up equal to ht.
* any knode returned by u32_get(tp, ...) will have ->ht_up->tp_c
point to tp->data
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
the only thing we used ht for was ht->tp_c and callers can get that
without going through ->tp_c at all; start with lifting that into
the callers, next commits will massage those, eventually removing
->tp_c altogether.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* calculate key *once*, not for each hash chain element
* let tc_u_hash() return the pointer to chain head rather than index -
callers are cleaner that way.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
unused
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
not used anymore
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested by modifying iproute2 to allow sending a divisor > 255
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Operation makes no sense. Nothing will actually break if we do so
(depth limit in u32_classify() will prevent infinite loops), but
according to maintainers it's best prohibited outright.
NOTE: doing so guarantees that u32_destroy() will trigger the call
of u32_destroy_hnode(); we might want to make that unconditional.
Test:
tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol ip prio 100 u32 \
link 800: offset at 0 mask 0f00 shift 6 plus 0 eat match ip protocol 6 ff
should fail with
Error: cls_u32: Not linking to root node
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
... and produce consistent error on attempt to delete such.
Existing check in u32_delete() is inconsistent - after
tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol ip prio 100 handle 1: u32 \
divisor 1
tc filter add dev eth0 parent ffff: protocol ip prio 200 handle 2: u32 \
divisor 1
both
tc filter delete dev eth0 parent ffff: protocol ip prio 100 handle 801: u32
and
tc filter delete dev eth0 parent ffff: protocol ip prio 100 handle 800: u32
will fail (at least with refcounting fixes), but the former will complain
about an attempt to remove a busy table, while the latter will recognize
it as root and yield "Not allowed to delete root node" instead.
The problem with the existing check is that several tcf_proto instances
might share the same tp->data and handle-to-hnode lookup will be the same
for all of them. So comparing an hnode to be deleted with tp->root won't
catch the case when one tp is used to try deleting the root of another.
Solution is trivial - mark the root hnodes explicitly upon allocation and
check for that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cls_u32.c misuses refcounts for struct tc_u_hnode - it counts references
via ->hlist and via ->tp_root together. u32_destroy() drops the former
and, in case when there had been links, leaves the sucker on the list.
As the result, there's nothing to protect it from getting freed once links
are dropped.
That also makes the "is it busy" check incapable of catching the root
hnode - it *is* busy (there's a reference from tp), but we don't see it as
something separate. "Is it our root?" check partially covers that, but
the problem exists for others' roots as well.
AFAICS, the minimal fix preserving the existing behaviour (where it doesn't
include oopsen, that is) would be this:
* count tp->root and tp_c->hlist as separate references. I.e.
have u32_init() set refcount to 2, not 1.
* in u32_destroy() we always drop the former;
in u32_destroy_hnode() - the latter.
That way we have *all* references contributing to refcount. List
removal happens in u32_destroy_hnode() (called only when ->refcnt is 1)
an in u32_destroy() in case of tc_u_common going away, along with
everything reachable from it. IOW, that way we know that
u32_destroy_key() won't free something still on the list (or pointed to by
someone's ->root).
Reproducer:
tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol ip prio 100 handle 1: \
u32 divisor 1
tc filter add dev eth0 parent ffff: protocol ip prio 200 handle 2: \
u32 divisor 1
tc filter add dev eth0 parent ffff: protocol ip prio 100 \
handle 1:0:11 u32 ht 1: link 801: offset at 0 mask 0f00 shift 6 \
plus 0 eat match ip protocol 6 ff
tc filter delete dev eth0 parent ffff: protocol ip prio 200
tc filter change dev eth0 parent ffff: protocol ip prio 100 \
handle 1:0:11 u32 ht 1: link 0: offset at 0 mask 0f00 shift 6 plus 0 \
eat match ip protocol 6 ff
tc filter delete dev eth0 parent ffff: protocol ip prio 100
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Via u32_change(), TCA_U32_SEL has an unspecified type in the netlink
policy, so max length isn't enforced, only minimum. This means nkeys
(from userspace) was being trusted without checking the actual size of
nla_len(), which could lead to a memory over-read, and ultimately an
exposure via a call to u32_dump(). Reachability is CAP_NET_ADMIN within
a namespace.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the offload tcf_proto_op in cls_u32 to generate an offload message for
each filter and the hashtable in the given tcf_proto. Call the specified
callback with this new offload message. The function only returns an error
if the callback rejects adding a 'hardware only' rule.
A filter contains a flag to indicate if it is in hardware or not. To
ensure the offload function properly maintains this flag, keep a reference
counter for the number of instances of the filter that are in hardware.
Only update the flag when this counter changes from or to 0.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 05f0fe6b74 ("RCU, workqueue: Implement rcu_work") introduces
new API's for dispatching work in a RCU callback. Now we can just
switch to the new API's for tc filters. This could get rid of a lot
of code.
Cc: Tejun Heo <tj@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we delete a u32 key via u32_delete_key(), we forget to
call idr_remove() to remove its handle from IDR.
Fixes: e7614370d6 ("net_sched: use idr to allocate u32 filter handles")
Reported-by: Marcin Kabiesz <admin@hostcenter.eu>
Tested-by: Marcin Kabiesz <admin@hostcenter.eu>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The offending commit wrongly assumes 1:1 mapping between block and q.
However, there are multiple blocks for a single q for classful qdiscs.
Since the obscure tc_u_common sharing mechanism expects it to be shared
among a qdisc, fix it by storing q pointer in case the block is not
shared.
Reported-by: Paweł Staszewski <pstaszewski@itcare.pl>
Reported-by: Cong Wang <xiyou.wangcong@gmail.com>
Fixes: 7fa9d974f3 ("net: sched: cls_u32: use block instead of q in tc_u_common")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Make allocations less aggressive in x_tables, from Minchal Hocko.
2) Fix netfilter flowtable Kconfig deps, from Pablo Neira Ayuso.
3) Fix connection loss problems in rtlwifi, from Larry Finger.
4) Correct DRAM dump length for some chips in ath10k driver, from Yu
Wang.
5) Fix ABORT handling in rxrpc, from David Howells.
6) Add SPDX tags to Sun networking drivers, from Shannon Nelson.
7) Some ipv6 onlink handling fixes, from David Ahern.
8) Netem packet scheduler interval calcualtion fix from Md. Islam.
9) Don't put crypto buffers on-stack in rxrpc, from David Howells.
10) Fix handling of error non-delivery status in netlink multicast
delivery over multiple namespaces, from Nicolas Dichtel.
11) Missing xdp flush in tuntap driver, from Jason Wang.
12) Synchonize RDS protocol netns/module teardown with rds object
management, from Sowini Varadhan.
13) Add nospec annotations to mpls, from Dan Williams.
14) Fix SKB truesize handling in TIPC, from Hoang Le.
15) Interrupt masking fixes in stammc from Niklas Cassel.
16) Don't allow ptr_ring objects to be sized outside of kmalloc's
limits, from Jason Wang.
17) Don't allow SCTP chunks to be built which will have a length
exceeding the chunk header's 16-bit length field, from Alexey
Kodanev.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (82 commits)
ibmvnic: Remove skb->protocol checks in ibmvnic_xmit
bpf: fix rlimit in reuseport net selftest
sctp: verify size of a new chunk in _sctp_make_chunk()
s390/qeth: fix SETIP command handling
s390/qeth: fix underestimated count of buffer elements
ptr_ring: try vmalloc() when kmalloc() fails
ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE
net: stmmac: remove redundant enable of PMT irq
net: stmmac: rename GMAC_INT_DEFAULT_MASK for dwmac4
net: stmmac: discard disabled flags in interrupt status register
ibmvnic: Reset long term map ID counter
tools/libbpf: handle issues with bpf ELF objects containing .eh_frames
selftests/bpf: add selftest that use test_libbpf_open
selftests/bpf: add test program for loading BPF ELF files
tools/libbpf: improve the pr_debug statements to contain section numbers
bpf: Sync kernel ABI header with tooling header for bpf_common.h
net: phy: fix phy_start to consider PHY_IGNORE_INTERRUPT
net: thunder: change q_len's type to handle max ring size
tipc: fix skb truesize/datasize ratio control
net/sched: cls_u32: fix cls_u32 on filter replace
...
Pull idr updates from Matthew Wilcox:
- test-suite improvements
- replace the extended API by improving the normal API
- performance improvement for IDRs which are 1-based rather than
0-based
- add documentation
* 'idr-2018-02-06' of git://git.infradead.org/users/willy/linux-dax:
idr: Add documentation
idr: Make 1-based IDRs more efficient
idr: Warn if old iterators see large IDs
idr: Rename idr_for_each_entry_ext
idr: Remove idr_alloc_ext
cls_u32: Convert to idr_alloc_u32
cls_u32: Reinstate cyclic allocation
cls_flower: Convert to idr_alloc_u32
cls_bpf: Convert to use idr_alloc_u32
cls_basic: Convert to use idr_alloc_u32
cls_api: Convert to idr_alloc_u32
net sched actions: Convert to use idr_alloc_u32
idr: Add idr_alloc_u32 helper
idr: Delete idr_find_ext function
idr: Delete idr_replace_ext function
idr: Delete idr_remove_ext function
IDR test suite: Check handling negative end correctly
idr test suite: Fix ida_test_random()
radix tree test suite: Remove ARRAY_SIZE
The following sequence is currently broken:
# tc qdisc add dev foo ingress
# tc filter replace dev foo protocol all ingress \
u32 match u8 0 0 action mirred egress mirror dev bar1
# tc filter replace dev foo protocol all ingress \
handle 800::800 pref 49152 \
u32 match u8 0 0 action mirred egress mirror dev bar2
Error: cls_u32: Key node flags do not match passed flags.
We have an error talking to the kernel, -1
The error comes from u32_change() when comparing new and
existing flags. The existing ones always contains one of
TCA_CLS_FLAGS_{,NOT}_IN_HW flag depending on offloading state.
These flags cannot be passed from userspace so the condition
(n->flags != flags) in u32_change() always fails.
Fix the condition so the flags TCA_CLS_FLAGS_NOT_IN_HW and
TCA_CLS_FLAGS_IN_HW are not taken into account.
Fixes: 24d3dc6d27 ("net/sched: cls_u32: Reflect HW offload status")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No real benefit to this classifier, but since we're allocating a u32
anyway, we should use this function.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Commit e7614370d6 ("net_sched: use idr to allocate u32 filter handles)
converted htid allocation to use the IDR. The ID allocated by this
scheme changes; it used to be cyclic, but now always allocates the
lowest available. The IDR supports cyclic allocation, so just use
the right function.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Changing idr_replace's 'id' argument to 'unsigned long' works for all
callers. Callers which passed a negative ID now get -ENOENT instead of
-EINVAL. No callers relied on this error value.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Li Shuang reported an Oops with cls_u32 due to an use-after-free
in u32_destroy_key(). The use-after-free can be triggered with:
dev=lo
tc qdisc add dev $dev root handle 1: htb default 10
tc filter add dev $dev parent 1: prio 5 handle 1: protocol ip u32 divisor 256
tc filter add dev $dev protocol ip parent 1: prio 5 u32 ht 800:: match ip dst\
10.0.0.0/8 hashkey mask 0x0000ff00 at 16 link 1:
tc qdisc del dev $dev root
Which causes the following kasan splat:
==================================================================
BUG: KASAN: use-after-free in u32_destroy_key.constprop.21+0x117/0x140 [cls_u32]
Read of size 4 at addr ffff881b83dae618 by task kworker/u48:5/571
CPU: 17 PID: 571 Comm: kworker/u48:5 Not tainted 4.15.0+ #87
Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.1.7 06/16/2016
Workqueue: tc_filter_workqueue u32_delete_key_freepf_work [cls_u32]
Call Trace:
dump_stack+0xd6/0x182
? dma_virt_map_sg+0x22e/0x22e
print_address_description+0x73/0x290
kasan_report+0x277/0x360
? u32_destroy_key.constprop.21+0x117/0x140 [cls_u32]
u32_destroy_key.constprop.21+0x117/0x140 [cls_u32]
u32_delete_key_freepf_work+0x1c/0x30 [cls_u32]
process_one_work+0xae0/0x1c80
? sched_clock+0x5/0x10
? pwq_dec_nr_in_flight+0x3c0/0x3c0
? _raw_spin_unlock_irq+0x29/0x40
? trace_hardirqs_on_caller+0x381/0x570
? _raw_spin_unlock_irq+0x29/0x40
? finish_task_switch+0x1e5/0x760
? finish_task_switch+0x208/0x760
? preempt_notifier_dec+0x20/0x20
? __schedule+0x839/0x1ee0
? check_noncircular+0x20/0x20
? firmware_map_remove+0x73/0x73
? find_held_lock+0x39/0x1c0
? worker_thread+0x434/0x1820
? lock_contended+0xee0/0xee0
? lock_release+0x1100/0x1100
? init_rescuer.part.16+0x150/0x150
? retint_kernel+0x10/0x10
worker_thread+0x216/0x1820
? process_one_work+0x1c80/0x1c80
? lock_acquire+0x1a5/0x540
? lock_downgrade+0x6b0/0x6b0
? sched_clock+0x5/0x10
? lock_release+0x1100/0x1100
? compat_start_thread+0x80/0x80
? do_raw_spin_trylock+0x190/0x190
? _raw_spin_unlock_irq+0x29/0x40
? trace_hardirqs_on_caller+0x381/0x570
? _raw_spin_unlock_irq+0x29/0x40
? finish_task_switch+0x1e5/0x760
? finish_task_switch+0x208/0x760
? preempt_notifier_dec+0x20/0x20
? __schedule+0x839/0x1ee0
? kmem_cache_alloc_trace+0x143/0x320
? firmware_map_remove+0x73/0x73
? sched_clock+0x5/0x10
? sched_clock_cpu+0x18/0x170
? find_held_lock+0x39/0x1c0
? schedule+0xf3/0x3b0
? lock_downgrade+0x6b0/0x6b0
? __schedule+0x1ee0/0x1ee0
? do_wait_intr_irq+0x340/0x340
? do_raw_spin_trylock+0x190/0x190
? _raw_spin_unlock_irqrestore+0x32/0x60
? process_one_work+0x1c80/0x1c80
? process_one_work+0x1c80/0x1c80
kthread+0x312/0x3d0
? kthread_create_worker_on_cpu+0xc0/0xc0
ret_from_fork+0x3a/0x50
Allocated by task 1688:
kasan_kmalloc+0xa0/0xd0
__kmalloc+0x162/0x380
u32_change+0x1220/0x3c9e [cls_u32]
tc_ctl_tfilter+0x1ba6/0x2f80
rtnetlink_rcv_msg+0x4f0/0x9d0
netlink_rcv_skb+0x124/0x320
netlink_unicast+0x430/0x600
netlink_sendmsg+0x8fa/0xd60
sock_sendmsg+0xb1/0xe0
___sys_sendmsg+0x678/0x980
__sys_sendmsg+0xc4/0x210
do_syscall_64+0x232/0x7f0
return_from_SYSCALL_64+0x0/0x75
Freed by task 112:
kasan_slab_free+0x71/0xc0
kfree+0x114/0x320
rcu_process_callbacks+0xc3f/0x1600
__do_softirq+0x2bf/0xc06
The buggy address belongs to the object at ffff881b83dae600
which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 24 bytes inside of
4096-byte region [ffff881b83dae600, ffff881b83daf600)
The buggy address belongs to the page:
page:ffffea006e0f6a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0
flags: 0x17ffffc0008100(slab|head)
raw: 0017ffffc0008100 0000000000000000 0000000000000000 0000000100070007
raw: dead000000000100 dead000000000200 ffff880187c0e600 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff881b83dae500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff881b83dae580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff881b83dae600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff881b83dae680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff881b83dae700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
The problem is that the htnode is freed before the linked knodes and the
latter will try to access the first at u32_destroy_key() time.
This change addresses the issue using the htnode refcnt to guarantee
the correct free order. While at it also add a RCU annotation,
to keep sparse happy.
v1 -> v2: use rtnl_derefence() instead of RCU read locks
v2 -> v3:
- don't check refcnt in u32_destroy_hnode()
- cleaned-up u32_destroy() implementation
- cleaned-up code comment
v3 -> v4:
- dropped unneeded comment
Reported-by: Li Shuang <shuali@redhat.com>
Fixes: c0d378ef12 ("net_sched: use tcf_queue_work() in u32 filter")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In a couple of points of the control path, n->ht_down is currently
accessed without the required RCU annotation. The accesses are
safe, but sparse complaints. Since we already held the
rtnl lock, let use rtnl_dereference().
Fixes: a1b7c5fd7f ("net: sched: add cls_u32 offload hooks for netdevs")
Fixes: de5df63228 ("net: sched: cls_u32 changes to knode must appear atomic to readers")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Propagate extack on removal of offloaded filter. Don't pass
extack from error paths.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass offload flags to the new implementation of
tc_cls_common_offload_init(). Extack will now only
be set if user requested skip_sw. hnodes need to
hold onto the flags now to be able to reuse them
on filter removal.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gustavo A. R. Silva