Commit Graph

7 Commits

Author SHA1 Message Date
Jakub Kicinski 44a8c4f33c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.

Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-04 21:28:59 -07:00
Johannes Berg c30a3c957c netlink: policy: correct validation type check
In the policy export for binary attributes I erroneously used
a != NLA_VALIDATE_NONE comparison instead of checking for the
two possible values, which meant that if a validation function
pointer ended up aliasing the min/max as negatives, we'd hit
a warning in nla_get_range_unsigned().

Fix this to correctly check for only the two types that should
be handled here, i.e. range with or without warn-too-long.

Reported-by: syzbot+353df1490da781637624@syzkaller.appspotmail.com
Fixes: 8aa26c575f ("netlink: make NLA_BINARY validation more flexible")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-31 12:01:15 -07:00
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
David S. Miller 7611cbb900 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-23 11:48:27 -07:00
Johannes Berg d1fb555929 netlink: fix state reallocation in policy export
Evidently, when I did this previously, we didn't have more than
10 policies and didn't run into the reallocation path, because
it's missing a memset() for the unused policies. Fix that.

Fixes: d07dcf9aad ("netlink: add infrastructure to expose policies to userspace")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-19 15:39:36 -07:00
Johannes Berg 8aa26c575f netlink: make NLA_BINARY validation more flexible
Add range validation for NLA_BINARY, allowing validation of any
combination of combination minimum or maximum lengths, using the
existing NLA_POLICY_RANGE()/NLA_POLICY_FULL_RANGE() macros, just
like for integers where the value is checked.

Also make NLA_POLICY_EXACT_LEN(), NLA_POLICY_EXACT_LEN_WARN()
and NLA_POLICY_MIN_LEN() special cases of this, removing the old
types NLA_EXACT_LEN and NLA_MIN_LEN.

This allows us to save some code where both minimum and maximum
lengths are requires, currently the policy only allows maximum
(NLA_BINARY), minimum (NLA_MIN_LEN) or exact (NLA_EXACT_LEN), so
a range of lengths cannot be accepted and must be checked by the
code that consumes the attributes later.

Also, this allows advertising the correct ranges in the policy
export to userspace. Here, NLA_MIN_LEN and NLA_EXACT_LEN already
were special cases of NLA_BINARY with min and min/max length
respectively.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-18 12:28:45 -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