06 Oct, 2020
1 commit
-
Rejecting non-native endian BTF overlapped with the addition
of support for it.The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.Signed-off-by: David S. Miller
03 Oct, 2020
3 commits
-
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
Reviewed-by: Johannes Berg
Signed-off-by: David S. Miller -
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
Reviewed-by: Johannes Berg
Signed-off-by: David S. Miller -
There are holes and oversized members in struct genl_family.
Before: /* size: 104, cachelines: 2, members: 16 */
After: /* size: 88, cachelines: 2, members: 16 */The command field in struct genlmsghdr is a u8, so no point
in the operation count being 32 bit. Also operation 0 is
usually undefined, so we only need 255 entries.netnsok and parallel_ops are only ever initialized to true.
We can grow the fields as needed, compiler should warn us
if someone tries to assign larger constants.Signed-off-by: Jakub Kicinski
Reviewed-by: Johannes Berg
Signed-off-by: David S. Miller
29 Sep, 2020
1 commit
-
Validation flags are missing kdoc, add it.
Fixes: ef6243acb478 ("genetlink: optionally validate strictly/dumps")
Signed-off-by: Jakub Kicinski
Signed-off-by: David S. Miller
18 Sep, 2020
1 commit
-
It is never used, so can remove it.
Signed-off-by: YueHaibing
Signed-off-by: David S. Miller
02 Jul, 2020
1 commit
-
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: c380d9a7afff ("genetlink: pass multicast bind/unbind to families")
Suggested-by: Cong Wang
Acked-by: Johannes Berg
Reported-by: kernel test robot
Signed-off-by: Sean Tranchetti
Signed-off-by: David S. Miller
30 Jun, 2020
1 commit
-
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)->attrsNote 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: 75cdbdd08900 ("net: ieee802154: have genetlink code to parse the attrs during dumpit")
Fixes: 057af7071344 ("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
Signed-off-by: Cong Wang
Signed-off-by: David S. Miller
06 Oct, 2019
3 commits
-
genl_family_attrbuf() function is no longer used by anyone, so remove it.
Signed-off-by: Jiri Pirko
Signed-off-by: David S. Miller -
Extend the dumpit info struct for attrs. Instead of existing attribute
validation do parse them and save in the info struct. Caller can benefit
from this and does not have to do parse itself. In order to properly
free attrs, genl_family pointer needs to be added to dumpit info struct
as well.Signed-off-by: Jiri Pirko
Signed-off-by: David S. Miller -
Currently the cb->data is taken by ops during non-parallel dumping.
Introduce a new structure genl_dumpit_info and store the ops there.
Distribute the info to both non-parallel and parallel dumping. Also add
a helper genl_dumpit_info() to easily get the info structure in the
dumpit callback from cb.Signed-off-by: Jiri Pirko
Signed-off-by: David S. Miller
28 Apr, 2019
3 commits
-
Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:@@
identifier ops;
expression X;
@@
struct genl_ops ops[] = {
...,
{
.cmd = X,
+ .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
...
},
...
};For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
This re-adds the parse and validate functions like nla_parse()
that are now actually strict after the previous rename and were
just split out to make sure everything is converted (and if not
compilation of the previous patch would fail.)Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
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 acceptedSplit 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 sizeThe 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_deprecatedUsing 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
Signed-off-by: David S. Miller
22 Mar, 2019
1 commit
-
Since maxattr is common, the policy can't really differ sanely,
so make it common as well.The only user that did in fact manage to make a non-common policy
is taskstats, which has to be really careful about it (since it's
still using a common maxattr!). This is no longer supported, but
we can fake it using pre_doit.This reduces the size of e.g. nl80211.o (which has lots of commands):
text data bss dec hex filename
398745 14323 2240 415308 6564c net/wireless/nl80211.o (before)
397913 14331 2240 414484 65314 net/wireless/nl80211.o (after)
--------------------------------
-832 +8 0 -824Which is obviously just 8 bytes for each command, and an added 8
bytes for the new policy pointer. I'm not sure why the ops list is
counted as .text though.Most of the code transformations were done using the following spatch:
@ops@
identifier OPS;
expression POLICY;
@@
struct genl_ops OPS[] = {
...,
{
- .policy = POLICY,
},
...
};@@
identifier ops.OPS;
expression ops.POLICY;
identifier fam;
expression M;
@@
struct genl_family fam = {
.ops = OPS,
.maxattr = M,
+ .policy = POLICY,
...
};This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing
the cb->data as ops, which we want to change in a later genl patch.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
30 Aug, 2018
1 commit
-
genl_err_attr() sets netlink_ext_ack::bad_attr which is a pointer to const
struct nlattr so make the attr argument also const.Signed-off-by: Michal Kubecek
Signed-off-by: David S. Miller
16 Nov, 2017
1 commit
-
According to the description, first argument of genlmsg_nlhdr() points to
what genlmsg_put() returns, i.e. beginning of user header. Therefore we
should only subtract size of genetlink header and netlink message header,
not user header.This also means we don't need to pass the pointer to genetlink family and
the same is true for genl_dump_check_consistent() which is the only caller
of genlmsg_nlhdr(). (Note that at the moment, these functions are only
used for families which do not have user header so that they are not
affected.)Fixes: 670dc2833d14 ("netlink: advertise incomplete dumps")
Signed-off-by: Michal Kubecek
Reviewed-by: Johannes Berg
Signed-off-by: David S. Miller
02 Nov, 2017
1 commit
-
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
05 Jun, 2017
1 commit
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commit d91824c08fbc ("genetlink: register family ops as array") removed the
ops_list member from both genl_family and genl_ops; while the
documentation of genl_family was updated accordingly by this patch,
ops_list remained in the documentation of the genl_ops object.
This patch fixes it by removing ops_list from genl_ops documentation.Signed-off-by: Rami Rosen
Signed-off-by: David S. Miller
14 Apr, 2017
2 commits
-
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
Pass the extended ACK reporting struct down from generic netlink to
the families, using the existing struct genl_info for simplicity.Also add support to set the extended ACK information from generic
netlink users.Signed-off-by: Johannes Berg
Reviewed-by: Jiri Pirko
Signed-off-by: David S. Miller
14 Nov, 2016
1 commit
-
The idr_alloc(), idr_remove(), et al. routines all expect IDs to be
signed integers. Therefore make the genl_family member 'id' signed
too.Signed-off-by: David S. Miller
28 Oct, 2016
4 commits
-
Since generic netlink family IDs are small integers, allocated
densely, IDR is an ideal match for lookups. Replace the existing
hand-written hash-table with IDR for allocation and lookup.This lets the families only be written to once, during register,
since the list_head can be removed and removal of a family won't
cause any writes.It also slightly reduces the code size (by about 1.3k on x86-64).
Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
Instead of providing macros/inline functions to initialize
the families, make all users initialize them statically and
get rid of the macros.This reduces the kernel code size by about 1.6k on x86-64
(with allyesconfig).Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
Static family IDs have never really been used, the only
use case was the workaround I introduced for those users
that assumed their family ID was also their multicast
group ID.Additionally, because static family IDs would never be
reserved by the generic netlink code, using a relatively
low ID would only work for built-in families that can be
registered immediately after generic netlink is started,
which is basically only the control family (apart from
the workaround code, which I also had to add code for so
it would reserve those IDs)Thus, anything other than GENL_ID_GENERATE is flawed and
luckily not used except in the cases I mentioned. Move
those workarounds into a few lines of code, and then get
rid of GENL_ID_GENERATE entirely, making it more robust.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
This helper function allows family implementations to access
their family's attrbuf. This gets rid of the attrbuf usage
in families, and also adds locking validation, since it's not
valid to use the attrbuf with parallel_ops or outside of the
dumpit callback.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
19 Feb, 2016
1 commit
-
This reverts commit bb9b18fb55b0 ("genl: Add genlmsg_new_unicast() for
unicast message allocation")'.Nothing wrong with it; its no longer needed since this was only for
mmapped netlink support.Signed-off-by: Florian Westphal
Signed-off-by: David S. Miller
16 Dec, 2015
1 commit
-
The start callback allows the caller to set up a context for the
dump callbacks. Presumably, the context can then be destroyed in
the done callback.Signed-off-by: Tom Herbert
Signed-off-by: David S. Miller
25 Sep, 2015
1 commit
-
The genl_notify function has too many arguments for no real reason - all
callers use genl_info to get them anyway. Just pass the genl_info down to
genl_notify.Signed-off-by: Jiri Benc
Signed-off-by: David S. Miller
13 Mar, 2015
1 commit
-
Having to say
> #ifdef CONFIG_NET_NS
> struct net *net;
> #endifin structures is a little bit wordy and a little bit error prone.
Instead it is possible to say:
> typedef struct {
> #ifdef CONFIG_NET_NS
> struct net *net;
> #endif
> } possible_net_t;And then in a header say:
> possible_net_t net;
Which is cleaner and easier to use and easier to test, as the
possible_net_t is always there no matter what the compile options.Further this allows read_pnet and write_pnet to be functions in all
cases which is better at catching typos.This change adds possible_net_t, updates the definitions of read_pnet
and write_pnet, updates optional struct net * variables that
write_pnet uses on to have the type possible_net_t, and finally fixes
up the b0rked users of read_pnet and write_pnet.Signed-off-by: "Eric W. Biederman"
Acked-by: Eric Dumazet
Signed-off-by: David S. Miller
28 Jan, 2015
1 commit
-
Conflicts:
arch/arm/boot/dts/imx6sx-sdb.dts
net/sched/cls_bpf.cTwo simple sets of overlapping changes.
Signed-off-by: David S. Miller
27 Jan, 2015
1 commit
-
The first user will be the next patch.
Signed-off-by: Joe Stringer
Acked-by: Pravin B Shelar
Signed-off-by: David S. Miller
18 Jan, 2015
1 commit
-
Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.This makes the very common pattern of
if (genlmsg_end(...) < 0) { ... }
be a whole bunch of dead code. Many places also simply do
return nlmsg_end(...);
and the caller is expected to deal with it.
This also commonly (at least for me) causes errors, because it is very
common to writeif (my_function(...))
/* error condition */and if my_function() does "return nlmsg_end()" this is of course wrong.
Additionally, there's not a single place in the kernel that actually
needs the message length returned, and if anyone needs it later then
it'll be very easy to just use skb->len there.Remove this, and make the functions void. This removes a bunch of dead
code as described above. The patch adds lines because I did- return nlmsg_end(...);
+ nlmsg_end(...);
+ return 0;I could have preserved all the function's return values by returning
skb->len, but instead I've audited all the places calling the affected
functions and found that none cared. A few places actually compared
the return value with < 0 with no change in behaviour, so I opted for the more
efficient version.One instance of the error I've made numerous times now is also present
in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't
check for
Signed-off-by: David S. Miller
17 Jan, 2015
2 commits
-
In addition to the problem Jeff Layton reported, I looked at the code
and reproduced the same warning by subscribing and removing the genl
family with a socket still open. This is a fairly tricky race which
originates in the fact that generic netlink allows the family to go
away while sockets are still open - unlike regular netlink which has
a module refcount for every open socket so in general this cannot be
triggered.Trying to resolve this issue by the obvious locking isn't possible as
it will result in deadlocks between unregistration and group unbind
notification (which incidentally lockdep doesn't find due to the home
grown locking in the netlink table.)To really resolve this, introduce a "closing socket" reference counter
(for generic netlink only, as it's the only affected family) in the
core netlink code and use that in generic netlink to wait for all the
sockets that are being closed at the same time as a generic netlink
family is removed.This fixes the race that when a socket is closed, it will should call
the unbind, but if the family is removed at the same time the unbind
will not find it, leading to the warning. The real problem though is
that in this case the unbind could actually find a new family that is
registered to have a multicast group with the same ID, and call its
mcast_unbind() leading to confusing.Also remove the warning since it would still trigger, but is now no
longer a problem.This also moves the code in af_netlink.c to before unreferencing the
module to avoid having the same problem in the normal non-genl case.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
The kernel-doc for the parallel_ops family struct member is
missing, add it.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
27 Dec, 2014
3 commits
-
Netlink families can exist in multiple namespaces, and for the most
part multicast subscriptions are per network namespace. Thus it only
makes sense to have bind/unbind notifications per network namespace.To achieve this, pass the network namespace of a given client socket
to the bind/unbind functions.Also do this in generic netlink, and there also make sure that any
bind for multicast groups that only exist in init_net is rejected.
This isn't really a problem if it is accepted since a client in a
different namespace will never receive any notifications from such
a group, but it can confuse the family if not rejected (it's also
possible to silently (without telling the family) accept it, but it
would also have to be ignored on unbind so families that take any
kind of action on bind/unbind won't do unnecessary work for invalid
clients like that.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
In order to make the newly fixed multicast bind/unbind
functionality in generic netlink, pass them down to the
appropriate family.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
There's no point to force the caller to know about the internal
genl_sock to use inside struct net, just have them pass the network
namespace. This doesn't really change code generation since it's
an inline, but makes the caller less magic - there's never any
reason to pass another socket.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
20 Sep, 2014
1 commit
-
This function is the counterpart of the function netlink_has_listeners().
Signed-off-by: Nicolas Dichtel
Acked-by: Pravin B Shelar
Signed-off-by: David S. Miller
07 Jan, 2014
1 commit
-
Allocates a new sk_buff large enough to cover the specified payload
plus required Netlink headers. Will check receiving socket for
memory mapped i/o capability and use it if enabled. Will fall back
to non-mapped skb if message size exceeds the frame size of the ring.Signed-of-by: Thomas Graf
Reviewed-by: Daniel Borkmann
Signed-off-by: Jesse Gross
