Commit graph

199 commits

Author SHA1 Message Date
Jakub Kicinski
5c670a010d genetlink: add a family pointer to struct genl_info
Having family in struct genl_info is quite useful. It cuts
down the number of arguments which need to be passed to
helpers which already take struct genl_info.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 15:01:03 -07:00
Jakub Kicinski
7288dd2fd4 genetlink: use attrs from struct genl_info
Since dumps carry struct genl_info now, use the attrs pointer
from genl_info and remove the one in struct genl_dumpit_info.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 15:00:45 -07:00
Jakub Kicinski
9272af109f genetlink: add struct genl_info to struct genl_dumpit_info
Netlink GET implementations must currently juggle struct genl_info
and struct netlink_callback, depending on whether they were called
from doit or dumpit.

Add genl_info to the dump state and populate the fields.
This way implementations can simply pass struct genl_info around.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 14:54:44 -07:00
Jakub Kicinski
bffcc6882a genetlink: remove userhdr from struct genl_info
Only three families use info->userhdr today and going forward
we discourage using fixed headers in new families.
So having the pointer to user header in struct genl_info
is an overkill. Compute the header pointer at runtime.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 14:54:44 -07:00
Jakub Kicinski
84817d8c60 genetlink: push conditional locking into dumpit/done
Add helpers which take/release the genl mutex based
on family->parallel_ops. Remove the separation between
handling of ops in locked and parallel families.

Future patches would make the duplicated code grow even more.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 14:54:44 -07:00
Jiri Pirko
5766946ea5 genetlink: add explicit ordering break check for split ops
Currently, if cmd in the split ops array is of lower value than the
previous one, genl_validate_ops() continues to do the checks as if
the values are equal. This may result in non-obvious WARN_ON() hit in
these check.

Instead, check the incorrect ordering explicitly and put a WARN_ON()
in case it is broken.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20230720111354.562242-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-21 18:49:12 -07:00
Jakub Kicinski
5ab8c41cef netlink: support extack in dump ->start()
Commit 4a19edb60d ("netlink: Pass extack to dump handlers")
added extack support to netlink dumps. It was focused on rtnl
and since rtnl does not use ->start(), ->done() callbacks
it ignored those. Genetlink on the other hand uses ->start()
extensively, for parsing and input validation.

Pass the extact in via struct netlink_dump_control and link
it to cb for the time of ->start(). Both struct netlink_dump_control
and extack itself live on the stack so we can't keep the same
extack for the duration of the dump. This means that the extack
visible in ->start() and each ->dump() callbacks will be different.
Corner cases like reporting a warning message in DONE across dump
calls are still not supported.

We could put the extack (for dumps) in the socket struct,
but layering makes it slightly awkward (extack pointer is decided
before the DO / DUMP split).

The genetlink dump error extacks are now surfaced:

  $ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
  lib.ynl.NlError: Netlink error: Invalid argument
  nl_len = 64 (48) nl_flags = 0x300 nl_type = 2
	error: -22	extack: {'msg': 'request header missing'}

Previously extack was missing:

  $ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
  lib.ynl.NlError: Netlink error: Invalid argument
  nl_len = 36 (20) nl_flags = 0x100 nl_type = 2
	error: -22

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-12 11:32:44 +01:00
Andy Shevchenko
d4545bf9c3 genetlink: Use string_is_terminated() helper
Use string_is_terminated() helper instead of cpecific memchr() call.
This shows better the intention of the call.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230208133153.22528-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-09 22:30:24 -08:00
Jakub Kicinski
c1b0510557 genetlink: fix single op policy dump when do is present
Jonathan reports crashes when running net-next in Meta's fleet.
Stats collection uses ethtool -I which does a per-op policy dump
to check if stats are supported. We don't initialize the dumpit
information if doit succeeds due to evaluation short-circuiting.

The crash may look like this:

   BUG: kernel NULL pointer dereference, address: 0000000000000cc0
   RIP: 0010:netlink_policy_dump_add_policy+0x174/0x2a0
     ctrl_dumppolicy_start+0x19f/0x2f0
     genl_start+0xe7/0x140

Or we may trigger a warning:

   WARNING: CPU: 1 PID: 785 at net/netlink/policy.c:87 netlink_policy_dump_get_policy_idx+0x79/0x80
   RIP: 0010:netlink_policy_dump_get_policy_idx+0x79/0x80
     ctrl_dumppolicy_put_op+0x214/0x360

depending on what garbage we pick up from the stack.

Reported-by: Jonathan Lemon <bsd@meta.com>
Fixes: 26588edbef ("genetlink: support split policies in ctrl_dumppolicy_put_op()")
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20221109183254.554051-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-10 13:52:51 -08:00
Jakub Kicinski
154ba79c9f genetlink: correctly begin the iteration over policies
The return value from genl_op_iter_init() only tells us if
there are any policies but to begin the iteration (and therefore
load the first entry) we need to call genl_op_iter_next().
Note that it's safe to call genl_op_iter_next() on a family
with no ops, it will just return false.

This may lead to various crashes, a warning in
netlink_policy_dump_get_policy_idx() when policy is not found
or.. no problem at all if the kmalloc'ed memory happens to be
zeroed.

Fixes: b502b3185c ("genetlink: use iterator in the op to policy map dumping")
Link: https://lore.kernel.org/r/20221108204128.330287-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-09 10:26:51 -08:00
Jakub Kicinski
aba22ca8cc genetlink: convert control family to split ops
Prove that the split ops work.
Sadly we need to keep bug-wards compatibility and specify
the same policy for dump as do, even tho we don't parse
inputs for the dump.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:17 +00:00
Jakub Kicinski
b8fd60c36a genetlink: allow families to use split ops directly
Let families to hook in the new split ops.

They are more flexible and should not be much larger than
full ops. Each split op is 40B while full op is 48B.
Devlink for example has 54 dos and 19 dumps, 2 of the dumps
do not have a do -> 56 full commands = 2688B.
Split ops would have taken 2920B, so 9% more space while
allowing individual per/post doit and per-type policies.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:17 +00:00
Jakub Kicinski
7acfbbe17c genetlink: inline old iteration helpers
All dumpers use the iterators now, inline the cmd by index
stuff into iterator code.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
b502b3185c genetlink: use iterator in the op to policy map dumping
We can't put the full iterator in the struct ctrl_dump_policy_ctx
because dump context is statically sized by netlink core.
Allocate it dynamically.

Rename policy to dump_map to make the logic a little easier to follow.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
6557461cd2 genetlink: add iterator for walking family ops
Subsequent changes will expose split op structures to users,
so walking the family ops with just an index will get harder.
Add a structured iterator, convert the simple cases.
Policy dumping needs more careful conversion.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
8d84322ae6 genetlink: inline genl_get_cmd()
All callers go via genl_get_cmd_split() now, so rename it
to genl_get_cmd() remove the original.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
26588edbef genetlink: support split policies in ctrl_dumppolicy_put_op()
Pass do and dump versions of the op to ctrl_dumppolicy_put_op()
so that it can provide a different policy index for the two.

Since we now look at policies, and those are set appropriately
there's no need to look at the GENL_DONT_VALIDATE_DUMP flag.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
92d3d9ba9b genetlink: add policies for both doit and dumpit in ctrl_dumppolicy_start()
Separate adding doit and dumpit policies for CTRL_CMD_GETPOLICY.
This has no effect until we actually allow do and dump to come
from different sources as netlink_policy_dump_add_policy()
does deduplication.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
e1a248911d genetlink: check for callback type at op load time
Now that genl_get_cmd_split() is informed what type of callback
user is trying to access (do or dump) we can check that this
callback is indeed available and return an error early.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
7747eb75f6 genetlink: load policy based on validation flags
Set the policy and maxattr pointers based on validation flags.
genl_family_rcv_msg_attrs_parse() will do nothing and return NULL
if maxattrs is zero, so no behavior change is expected.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
20b0b53aca genetlink: introduce split op representation
We currently have two forms of operations - small ops and "full" ops
(or just ops). The former does not have pointers for some of the less
commonly used features (namely dump start/done and policy).

The "full" ops, however, still don't contain all the necessary
information. In particular the policy is per command ID, while
do and dump often accept different attributes. It's also not
possible to define different pre_doit and post_doit callbacks
for different commands within the family.

At the same time a lot of commands do not support dumping and
therefore all the dump-related information is wasted space.

Create a new command representation which can hold info about
a do implementation or a dump implementation, but not both at
the same time.

Use this new representation on the command execution path
(genl_family_rcv_msg) as we either run a do or a dump and
don't have to create a "full" op there.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
ff14adbd87 genetlink: refactor the cmd <> policy mapping dump
The code at the top of ctrl_dumppolicy() dumps mappings between
ops and policies. It supports dumping both the entire family and
single op if dump is filtered. But both of those cases are handled
inside a loop, which makes the logic harder to follow and change.
Refactor to split the two cases more clearly.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-07 12:30:16 +00:00
Jakub Kicinski
ce48ebdd56 genetlink: limit the use of validation workarounds to old ops
During review of previous change another thing came up - we should
limit the use of validation workarounds to old commands.
Don't list the workarounds one by one, as we're rejecting all existing
ones. We can deal with the masking in the unlikely event that new flag
is added.

Link: https://lore.kernel.org/all/6ba9f727e555fd376623a298d5d305ad408c3d47.camel@sipsolutions.net/
Link: https://lore.kernel.org/r/20221026001524.1892202-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-27 08:20:21 -07:00
Jakub Kicinski
4fa86555d1 genetlink: piggy back on resv_op to default to a reject policy
To keep backward compatibility we used to leave attribute parsing
to the family if no policy is specified. This becomes tedious as
we move to more strict validation. Families must define reject all
policies if they don't want any attributes accepted.

Piggy back on the resv_start_op field as the switchover point.
AFAICT only ethtool has added new commands since the resv_start_op
was defined, and it has per-op policies so this should be a no-op.

Nonetheless the patch should still go into v6.1 for consistency.

Link: https://lore.kernel.org/all/20221019125745.3f2e7659@kernel.org/
Link: https://lore.kernel.org/r/20221021193532.1511293-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-24 19:08:46 -07:00
Jakub Kicinski
cff2d762cd genetlink: reject use of nlmsg_flags for new commands
Commit 9c5d03d362 ("genetlink: start to validate reserved header bytes")
introduced extra validation for genetlink headers. We had to gate it
to only apply to new commands, to maintain bug-wards compatibility.
Use this opportunity (before the new checks make it to Linus's tree)
to add more conditions.

Validate that Generic Netlink families do not use nlmsg_flags outside
of the well-understood set.

Link: https://lore.kernel.org/all/20220928073709.1b93b74a@kernel.org/
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20220929142809.1167546-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-30 17:43:09 -07:00
Jakub Kicinski
9c5d03d362 genetlink: start to validate reserved header bytes
We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-29 12:47:15 +01:00
Jiri Pirko
8f1948bdcf genetlink: hold read cb_lock during iteration of genl_fam_idr in genl_bind()
In genl_bind(), currently genl_lock and write cb_lock are taken
for iteration of genl_fam_idr and processing of static values
stored in struct genl_family. Take just read cb_lock for this task
as it is sufficient to guard the idr and the struct against
concurrent genl_register/unregister_family() calls.

This will allow to run genl command processing in genl_rcv() and
mnl_socket_setsockopt(.., NETLINK_ADD_MEMBERSHIP, ..) in parallel.

Reported-by: Vikas Gupta <vikas.gupta@broadcom.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20220825081940.1283335-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-26 18:47:21 -07:00
Jakub Kicinski
249801360d net: genl: fix error path memory leak in policy dumping
If construction of the array of policies fails when recording
non-first policy we need to unwind.

netlink_policy_dump_add_policy() itself also needs fixing as
it currently gives up on error without recording the allocated
pointer in the pstate pointer.

Reported-by: syzbot+dc54d9ba8153b216cae0@syzkaller.appspotmail.com
Fixes: 50a896cf2d ("genetlink: properly support per-op policy dumping")
Link: https://lore.kernel.org/r/20220816161939.577583-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-18 10:20:48 -07:00
Yajun Deng
bc83052561 net: netlink: Remove unused function
lockdep_genl_is_held() and its caller arm not used now, just remove them.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Link: https://lore.kernel.org/r/20210729074854.8968-1-yajun.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-30 18:35:47 +02:00
Yajun Deng
f9b282b36d net: netlink: add the case when nlh is NULL
Add the case when nlh is NULL in nlmsg_report(),
so that the caller doesn't need to deal with this case.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-27 11:43:50 +01:00
Florian Westphal
4d54cc3211 mptcp: avoid lock_fast usage in accept path
Once event support is added this may need to allocate memory while msk
lock is held with softirqs disabled.

Not using lock_fast also allows to do the allocation with GFP_KERNEL.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 16:31:46 -08:00
Jakub Kicinski
e992a6eda9 genetlink: allow dumping command-specific policy
Right now CTRL_CMD_GETPOLICY can only dump the family-wide
policy. Support dumping policy of a specific op.

v3:
 - rebase after per-op policy export and handle that
v2:
 - make cmd U32, just in case.
v1:
 - don't echo op in the output in a naive way, this should
   make it cleaner to extend the output format for dumping
   policies for all the commands at once in the future.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20201001225933.1373426-11-kuba@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03 14:18:29 -07:00
Johannes Berg
50a896cf2d genetlink: properly support per-op policy dumping
Add support for per-op policy dumping. The data is pretty much
as before, except that now the assumption that the policy with
index 0 is "the" policy no longer holds - you now need to look
at the new CTRL_ATTR_OP_POLICY attribute which is a nested attr
(indexed by op) containing attributes for do and dump policies.

When a single op is requested, the CTRL_ATTR_OP_POLICY will be
added in the same way, since do and dump policies may differ.

v2:
 - conditionally advertise per-command policies only if there
   actually is a policy being used for the do/dump and it's
   present at all

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03 14:18:29 -07:00
Johannes Berg
aa85ee5f95 genetlink: factor skb preparation out of ctrl_dumppolicy()
We'll need this later for the per-op policy index dump.

Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03 14:18:29 -07:00
Johannes Berg
04a351a62b netlink: rework policy dump to support multiple policies
Rework the policy dump code a bit to support adding multiple
policies to a single dump, in order to e.g. support per-op
policies in generic netlink.

v2:
 - move kernel-doc to implementation [Jakub]
 - squash the first patch to not flip-flop on the prototype
   [Jakub]
 - merge netlink_policy_dump_get_policy_idx() with the old
   get_policy_idx() we already had
 - rebase without Jakub's patch to have per-op dump

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03 14:18:29 -07:00
Jakub Kicinski
a4bb4f5fc8 genetlink: switch control commands to per-op policies
In preparation for adding a new attribute to CTRL_CMD_GETPOLICY
split the policies for getpolicy and getfamily apart.

This will cause a slight user-visible change in that dumping
the policies will switch from per family to per op, but
supposedly sniffer-type applications (which are the main use
case for policy dumping thus far) should support both, anyway.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:12 -07:00
Jakub Kicinski
8e1ed28fd8 genetlink: use parsed attrs in dumppolicy
Attributes are already parsed based on the policy specified
in the family and ready-to-use in info->attrs. No need to
call genlmsg_parse() again.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:12 -07:00
Jakub Kicinski
48526a0f4c genetlink: bring back per op policy
Add policy to the struct genl_ops structure, this time
with maxattr, so it can be used properly.

Propagate .policy and .maxattr from the family
in genl_get_cmd() if needed, this way the rest of the
code does not have to worry if the policy is per op
or global.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:12 -07:00
Jakub Kicinski
78ade619c1 genetlink: use .start callback for dumppolicy
The structure of ctrl_dumppolicy() is clearly split into
init and dumping. Move the init to a .start callback
for clarity, it's a more idiomatic netlink dump code structure.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:12 -07:00
Jakub Kicinski
adc848450f genetlink: add a structure for dump state
Whenever netlink dump uses more than 2 cb->args[] entries
code gets hard to read. We're about to add more state to
ctrl_dumppolicy() so create a structure.

Since the structure is typed and clearly named we can remove
the local fam_id variable and use ctx->fam_id directly.

v3:
 - rebase onto explicit free fix
v1:
 - s/nl_policy_dump/netlink_policy_dump_state/
 - forward declare struct netlink_policy_dump_state,
   and move from passing unsigned long to actual pointer type
 - add build bug on
 - u16 fam_id
 - s/args/ctx/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:12 -07:00
Jakub Kicinski
0b588afdd1 genetlink: add small version of ops
We want to add maxattr and policy back to genl_ops, to enable
dumping per command policy to user space. This, however, would
cause bloat for all the families with global policies. Introduce
smaller version of ops (half the size of genl_ops). Translate
these smaller ops into a full blown struct before use in the
core.

v1:
 - use struct assignment
 - put a full copy of the op in struct genl_dumpit_info
 - s/light/small/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:11 -07:00
Johannes Berg
949ca6b82e netlink: fix policy dump leak
[ Upstream commit a95bc734e6 ]

If userspace doesn't complete the policy dump, we leak the
allocated state. Fix this.

Fixes: d07dcf9aad ("netlink: add infrastructure to expose policies to userspace")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 13:07:42 -07:00
Randy Dunlap
8540591885 net: netlink: delete repeated words
Drop duplicated words in net/netlink/.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-24 17:31:20 -07:00
Linus Torvalds
96e3f3c16b - Add support to enable/disable the thermal zones resulting on core code and
drivers cleanup (Andrzej Pietrasiewicz)
 
 - Add generic netlink support for userspace notifications: events, temperature
   and discovery commands (Daniel Lezcano)
 
 - Fix redundant initialization for a ret variable (Colin Ian King)
 
 - Remove the clock cooling code as it is used nowhere (Amit Kucheria)
 
 - Add the rcar_gen3_thermal's r8a774e1 support (Marian-Cristian Rotariu)
 
 - Replace all references to thermal.txt in the documentation to the
   corresponding yaml files (Amit Kucheria)
 
 - Add maintainer entry for the IPA (Lukasz Luba)
 
 - Add support for MSM8939 for the tsens (Shawn Guo)
 
 - Update power allocator and devfreq cooling to SPDX licensing (Lukasz Luba)
 
 - Add Cannon Lake Low Power PCH support (Sumeet Pawnikar)
 
 - Add tsensor support for V2 mediatek thermal system (Henry Yen)
 
 - Fix thermal zone lookup by ID for the core code (Thierry Reding)
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Merge tag 'thermal-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux

Pull thermal updates from Daniel Lezcano:

 - Add support to enable/disable the thermal zones resulting on core
   code and drivers cleanup (Andrzej Pietrasiewicz)

 - Add generic netlink support for userspace notifications: events,
   temperature and discovery commands (Daniel Lezcano)

 - Fix redundant initialization for a ret variable (Colin Ian King)

 - Remove the clock cooling code as it is used nowhere (Amit Kucheria)

 - Add the rcar_gen3_thermal's r8a774e1 support (Marian-Cristian
   Rotariu)

 - Replace all references to thermal.txt in the documentation to the
   corresponding yaml files (Amit Kucheria)

 - Add maintainer entry for the IPA (Lukasz Luba)

 - Add support for MSM8939 for the tsens (Shawn Guo)

 - Update power allocator and devfreq cooling to SPDX licensing (Lukasz
   Luba)

 - Add Cannon Lake Low Power PCH support (Sumeet Pawnikar)

 - Add tsensor support for V2 mediatek thermal system (Henry Yen)

 - Fix thermal zone lookup by ID for the core code (Thierry Reding)

* tag 'thermal-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux: (40 commits)
  thermal: intel: intel_pch_thermal: Add Cannon Lake Low Power PCH support
  thermal: mediatek: Add tsensor support for V2 thermal system
  thermal: mediatek: Prepare to add support for other platforms
  thermal: Update power allocator and devfreq cooling to SPDX licensing
  MAINTAINERS: update entry to thermal governors file name prefixing
  thermal: core: Add thermal zone enable/disable notification
  thermal: qcom: tsens-v0_1: Add support for MSM8939
  dt-bindings: tsens: qcom: Document MSM8939 compatible
  thermal: core: Fix thermal zone lookup by ID
  thermal: int340x: processor_thermal: fix: update Jasper Lake PCI id
  thermal: imx8mm: Support module autoloading
  thermal: ti-soc-thermal: Fix reversed condition in ti_thermal_expose_sensor()
  MAINTAINERS: Add maintenance information for IPA
  thermal: rcar_gen3_thermal: Do not shadow thcode variable
  dt-bindings: thermal: Get rid of thermal.txt and replace references
  thermal: core: Move initialization after core initcall
  thermal: netlink: Improve the initcall ordering
  net: genetlink: Move initialization to core_initcall
  thermal: rcar_gen3_thermal: Add r8a774e1 support
  thermal/drivers/clock_cooling: Remove clock_cooling code
  ...
2020-08-06 18:10:55 -07:00
Daniel Lezcano
c62e7ac395 net: genetlink: Move initialization to core_initcall
The generic netlink is initialized far after the netlink protocol
itself at subsys_initcall. The devlink is initialized at the same
level, but after, as shown by a disassembly of the vmlinux:

[ ... ]
374 ffff8000115f22c0 <__initcall_devlink_init4>:
375 ffff8000115f22c4 <__initcall_genl_init4>:
[ ... ]

The function devlink_init() calls genl_register_family() before the
generic netlink subsystem is initialized.

As the generic netlink initcall level is set since 2005, it seems that
was not a problem, but now we have the thermal framework initialized
at the core_initcall level which creates the generic netlink family
and sends a notification which leads to a subtle memory corruption
only detectable when the CONFIG_INIT_ON_ALLOC_DEFAULT_ON option is set
with the earlycon at init time.

The thermal framework needs to be initialized early in order to begin
the mitigation as soon as possible. Moving it to postcore_initcall is
acceptable.

This patch changes the initialization level for the generic netlink
family to the core_initcall and comes after the netlink protocol
initialization.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20200715074120.8768-1-daniel.lezcano@linaro.org
2020-07-21 10:40:08 +02:00
Sean Tranchetti
1e82a62fec genetlink: remove genl_bind
A potential deadlock can occur during registering or unregistering a
new generic netlink family between the main nl_table_lock and the
cb_lock where each thread wants the lock held by the other, as
demonstrated below.

1) Thread 1 is performing a netlink_bind() operation on a socket. As part
   of this call, it will call netlink_lock_table(), incrementing the
   nl_table_users count to 1.
2) Thread 2 is registering (or unregistering) a genl_family via the
   genl_(un)register_family() API. The cb_lock semaphore will be taken for
   writing.
3) Thread 1 will call genl_bind() as part of the bind operation to handle
   subscribing to GENL multicast groups at the request of the user. It will
   attempt to take the cb_lock semaphore for reading, but it will fail and
   be scheduled away, waiting for Thread 2 to finish the write.
4) Thread 2 will call netlink_table_grab() during the (un)registration
   call. However, as Thread 1 has incremented nl_table_users, it will not
   be able to proceed, and both threads will be stuck waiting for the
   other.

genl_bind() is a noop, unless a genl_family implements the mcast_bind()
function to handle setting up family-specific multicast operations. Since
no one in-tree uses this functionality as Cong pointed out, simply removing
the genl_bind() function will remove the possibility for deadlock, as there
is no attempt by Thread 1 above to take the cb_lock semaphore.

Fixes: c380d9a7af ("genetlink: pass multicast bind/unbind to families")
Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Johannes Berg <johannes.berg@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-01 15:49:11 -07:00
Cong Wang
bf64ff4c2a genetlink: get rid of family->attrbuf
genl_family_rcv_msg_attrs_parse() reuses the global family->attrbuf
when family->parallel_ops is false. However, family->attrbuf is not
protected by any lock on the genl_family_rcv_msg_doit() code path.

This leads to several different consequences, one of them is UAF,
like the following:

genl_family_rcv_msg_doit():		genl_start():
					  genl_family_rcv_msg_attrs_parse()
					    attrbuf = family->attrbuf
					    __nlmsg_parse(attrbuf);
  genl_family_rcv_msg_attrs_parse()
    attrbuf = family->attrbuf
    __nlmsg_parse(attrbuf);
					  info->attrs = attrs;
					  cb->data = info;

netlink_unicast_kernel():
 consume_skb()
					genl_lock_dumpit():
					  genl_dumpit_info(cb)->attrs

Note family->attrbuf is an array of pointers to the skb data, once
the skb is freed, any dereference of family->attrbuf will be a UAF.

Maybe we could serialize the family->attrbuf with genl_mutex too, but
that would make the locking more complicated. Instead, we can just get
rid of family->attrbuf and always allocate attrbuf from heap like the
family->parallel_ops==true code path. This may add some performance
overhead but comparing with taking the global genl_mutex, it still
looks better.

Fixes: 75cdbdd089 ("net: ieee802154: have genetlink code to parse the attrs during dumpit")
Fixes: 057af70713 ("net: tipc: have genetlink code to parse the attrs during dumpit")
Reported-and-tested-by: syzbot+3039ddf6d7b13daf3787@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+80cad1e3cb4c41cde6ff@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+736bcbcb11b60d0c0792@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+520f8704db2b68091d44@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+c96e4dfb32f8987fdeed@syzkaller.appspotmail.com
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:15:57 -07:00
Cong Wang
b65ce380b7 genetlink: clean up family attributes allocations
genl_family_rcv_msg_attrs_parse() and genl_family_rcv_msg_attrs_free()
take a boolean parameter to determine whether allocate/free the family
attrs. This is unnecessary as we can just check family->parallel_ops.
More importantly, callers would not need to worry about pairing these
parameters correctly after this patch.

And this fixes a memory leak, as after commit c36f055591
("genetlink: fix memory leaks in genl_family_rcv_msg_dumpit()")
we call genl_family_rcv_msg_attrs_parse() for both parallel and
non-parallel cases.

Fixes: c36f055591 ("genetlink: fix memory leaks in genl_family_rcv_msg_dumpit()")
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-12 14:05:08 -07:00
Cong Wang
c36f055591 genetlink: fix memory leaks in genl_family_rcv_msg_dumpit()
There are two kinds of memory leaks in genl_family_rcv_msg_dumpit():

1. Before we call ops->start(), whenever an error happens, we forget
   to free the memory allocated in genl_family_rcv_msg_dumpit().

2. When ops->start() fails, the 'info' has been already installed on
   the per socket control block, so we should not free it here. More
   importantly, nlk->cb_running is still false at this point, so
   netlink_sock_destruct() cannot free it either.

The first kind of memory leaks is easier to resolve, but the second
one requires some deeper thoughts.

After reviewing how netfilter handles this, the most elegant solution
I find is just to use a similar way to allocate the memory, that is,
moving memory allocations from caller into ops->start(). With this,
we can solve both kinds of memory leaks: for 1), no memory allocation
happens before ops->start(); for 2), ops->start() handles its own
failures and 'info' is installed to the socket control block only
when success. The only ugliness here is we have to pass all local
variables on stack via a struct, but this is not hard to understand.

Alternatively, we can introduce a ops->free() to solve this too,
but it is overkill as only genetlink has this problem so far.

Fixes: 1927f41a22 ("net: genetlink: introduce dump info struct to be available during dumpit op")
Reported-by: syzbot+21f04f481f449c8db840@syzkaller.appspotmail.com
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Shaochun Chen <cscnull@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-04 15:33:45 -07:00
Johannes Berg
d07dcf9aad netlink: add infrastructure to expose policies to userspace
Add, and use in generic netlink, helpers to dump out a netlink
policy to userspace, including all the range validation data,
nested policies etc.

This lets userspace discover what the kernel understands.

For families/commands other than generic netlink, the helpers
need to be used directly in an appropriate command, or we can
add some infrastructure (a new netlink family) that those can
register their policies with for introspection. I'm not that
familiar with non-generic netlink, so that's left out for now.

The data exposed to userspace also includes min and max length
for binary/string data, I've done that instead of letting the
userspace tools figure out whether min/max is intended based
on the type so that we can extend this later in the kernel, we
might want to just use the range data for example.

Because of this, I opted to not directly expose the NLA_*
values, even if some of them are already exposed via BPF, as
with min/max length we don't need to have different types here
for NLA_BINARY/NLA_MIN_LEN/NLA_EXACT_LEN, we just make them
all NL_ATTR_TYPE_BINARY with min/max length optionally set.

Similarly, we don't really need NLA_MSECS, and perhaps can
remove it in the future - but not if we encode it into the
userspace API now. It gets mapped to NL_ATTR_TYPE_U64 here.

Note that the exposing here corresponds to the strict policy
interpretation, and NLA_UNSPEC items are omitted entirely.
To get those, change them to NLA_MIN_LEN which behaves in
exactly the same way, but is exposed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 17:51:42 -07:00