Pull more random number generator updates from Jason Donenfeld:
"This time with some large scale treewide cleanups.
The intent of this pull is to clean up the way callers fetch random
integers. The current rules for doing this right are:
- If you want a secure or an insecure random u64, use get_random_u64()
- If you want a secure or an insecure random u32, use get_random_u32()
The old function prandom_u32() has been deprecated for a while
now and is just a wrapper around get_random_u32(). Same for
get_random_int().
- If you want a secure or an insecure random u16, use get_random_u16()
- If you want a secure or an insecure random u8, use get_random_u8()
- If you want secure or insecure random bytes, use get_random_bytes().
The old function prandom_bytes() has been deprecated for a while
now and has long been a wrapper around get_random_bytes()
- If you want a non-uniform random u32, u16, or u8 bounded by a
certain open interval maximum, use prandom_u32_max()
I say "non-uniform", because it doesn't do any rejection sampling
or divisions. Hence, it stays within the prandom_*() namespace, not
the get_random_*() namespace.
I'm currently investigating a "uniform" function for 6.2. We'll see
what comes of that.
By applying these rules uniformly, we get several benefits:
- By using prandom_u32_max() with an upper-bound that the compiler
can prove at compile-time is ≤65536 or ≤256, internally
get_random_u16() or get_random_u8() is used, which wastes fewer
batched random bytes, and hence has higher throughput.
- By using prandom_u32_max() instead of %, when the upper-bound is
not a constant, division is still avoided, because
prandom_u32_max() uses a faster multiplication-based trick instead.
- By using get_random_u16() or get_random_u8() in cases where the
return value is intended to indeed be a u16 or a u8, we waste fewer
batched random bytes, and hence have higher throughput.
This series was originally done by hand while I was on an airplane
without Internet. Later, Kees and I worked on retroactively figuring
out what could be done with Coccinelle and what had to be done
manually, and then we split things up based on that.
So while this touches a lot of files, the actual amount of code that's
hand fiddled is comfortably small"
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
prandom: remove unused functions
treewide: use get_random_bytes() when possible
treewide: use get_random_u32() when possible
treewide: use get_random_{u8,u16}() when possible, part 2
treewide: use get_random_{u8,u16}() when possible, part 1
treewide: use prandom_u32_max() when possible, part 2
treewide: use prandom_u32_max() when possible, part 1
A WARN_ON call trace would be triggered when 'ct(commit, alg=helper)'
applies on a confirmed connection:
WARNING: CPU: 0 PID: 1251 at net/netfilter/nf_conntrack_extend.c:98
RIP: 0010:nf_ct_ext_add+0x12d/0x150 [nf_conntrack]
Call Trace:
<TASK>
nf_ct_helper_ext_add+0x12/0x60 [nf_conntrack]
__nf_ct_try_assign_helper+0xc4/0x160 [nf_conntrack]
__ovs_ct_lookup+0x72e/0x780 [openvswitch]
ovs_ct_execute+0x1d8/0x920 [openvswitch]
do_execute_actions+0x4e6/0xb60 [openvswitch]
ovs_execute_actions+0x60/0x140 [openvswitch]
ovs_packet_cmd_execute+0x2ad/0x310 [openvswitch]
genl_family_rcv_msg_doit.isra.15+0x113/0x150
genl_rcv_msg+0xef/0x1f0
which can be reproduced with these OVS flows:
table=0, in_port=veth1,tcp,tcp_dst=2121,ct_state=-trk
actions=ct(commit, table=1)
table=1, in_port=veth1,tcp,tcp_dst=2121,ct_state=+trk+new
actions=ct(commit, alg=ftp),normal
The issue was introduced by commit 248d45f1e1 ("openvswitch: Allow
attaching helper in later commit") where it somehow removed the check
of nf_ct_is_confirmed before asigning the helper. This patch is to fix
it by bringing it back.
Fixes: 248d45f1e1 ("openvswitch: Allow attaching helper in later commit")
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Tested-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/c5c9092a22a2194650222bffaf786902613deb16.1665085502.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Similar to the previous commit, the Netlink interface of the OVS
conntrack module was restricted to global CAP_NET_ADMIN by using
GENL_ADMIN_PERM. This is changed to GENL_UNS_ADMIN_PERM to support
unprivileged containers in non-initial user namespace.
Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The Netlink interface for metering was restricted to global CAP_NET_ADMIN
by using GENL_ADMIN_PERM. To allow metring in a non-inital user namespace,
e.g., a container, this is changed to GENL_UNS_ADMIN_PERM.
Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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>
CRIU is preserving ifindexes of net devices after restoration. However,
current Open vSwitch API does not allow to target ifindex, so we cannot
correctly restore OVS configuration.
Add new OVS_DP_ATTR_IFINDEX for OVS_DP_CMD_NEW and use it as desired
ifindex.
Use OVS_VPORT_ATTR_IFINDEX during OVS_VPORT_CMD_NEW to specify new netdev
ifindex.
Signed-off-by: Andrey Zhadchenko <andrey.zhadchenko@virtuozzo.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently queue_userspace_packet will call kfree_skb for all frames,
whether or not an error occurred. This can result in a single dropped
frame being reported as multiple drops in dropwatch. This functions
caller may also call kfree_skb in case of an error. This patch will
consume the skbs instead and allow caller's to use kfree_skb.
Signed-off-by: Mike Pattrick <mkp@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109957
Signed-off-by: David S. Miller <davem@davemloft.net>
Frames sent to userspace can be reported as dropped in
ovs_dp_process_packet, however, if they are dropped in the netlink code
then netlink_attachskb will report the same frame as dropped.
This patch checks for error codes which indicate that the frame has
already been freed.
Signed-off-by: Mike Pattrick <mkp@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109946
Signed-off-by: David S. Miller <davem@davemloft.net>
When a packet enters the OVS datapath and does not match any existing
flows installed in the kernel flow cache, the packet will be sent to
userspace to be parsed, and a new flow will be created. The kernel and
OVS rely on each other to parse packet fields in the same way so that
packets will be handled properly.
As per the design document linked below, OVS expects all later IPv6
fragments to have nw_proto=44 in the flow key, so they can be correctly
matched on OpenFlow rules. OpenFlow controllers create pipelines based
on this design.
This behavior was changed by the commit in the Fixes tag so that
nw_proto equals the next_header field of the last extension header.
However, there is no counterpart for this change in OVS userspace,
meaning that this field is parsed differently between OVS and the
kernel. This is a problem because OVS creates actions based on what is
parsed in userspace, but the kernel-provided flow key is used as a match
criteria, as described in Documentation/networking/openvswitch.rst. This
leads to issues such as packets incorrectly matching on a flow and thus
the wrong list of actions being applied to the packet. Such changes in
packet parsing cannot be implemented without breaking the userspace.
The offending commit is partially reverted to restore the expected
behavior.
The change technically made sense and there is a good reason that it was
implemented, but it does not comply with the original design of OVS.
If in the future someone wants to implement such a change, then it must
be user-configurable and disabled by default to preserve backwards
compatibility with existing OVS versions.
Cc: stable@vger.kernel.org
Fixes: fa642f0883 ("openvswitch: Derive IP protocol number for IPv6 later frags")
Link: https://docs.openvswitch.org/en/latest/topics/design/#fragments
Signed-off-by: Rosemarie O'Riorden <roriorden@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/20220621204845.9721-1-roriorden@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If packet headers changed, the cached nfct is no longer relevant
for the packet and attempt to re-use it leads to the incorrect packet
classification.
This issue is causing broken connectivity in OpenStack deployments
with OVS/OVN due to hairpin traffic being unexpectedly dropped.
The setup has datapath flows with several conntrack actions and tuple
changes between them:
actions:ct(commit,zone=8,mark=0/0x1,nat(src)),
set(eth(src=00:00:00:00:00:01,dst=00:00:00:00:00:06)),
set(ipv4(src=172.18.2.10,dst=192.168.100.6,ttl=62)),
ct(zone=8),recirc(0x4)
After the first ct() action the packet headers are almost fully
re-written. The next ct() tries to re-use the existing nfct entry
and marks the packet as invalid, so it gets dropped later in the
pipeline.
Clearing the cached conntrack entry whenever packet tuple is changed
to avoid the issue.
The flow key should not be cleared though, because we should still
be able to match on the ct_state if the recirculation happens after
the tuple change but before the next ct() action.
Cc: stable@vger.kernel.org
Fixes: 7f8a436eaa ("openvswitch: Add conntrack action")
Reported-by: Frode Nordahl <frode.nordahl@canonical.com>
Link: https://mail.openvswitch.org/pipermail/ovs-discuss/2022-May/051829.html
Link: https://bugs.launchpad.net/ubuntu/+source/ovn/+bug/1967856
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://lore.kernel.org/r/20220606221140.488984-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Given a sufficiently large number of actions, while copying and
reserving memory for a new action of a new flow, if next_offset is
greater than MAX_ACTIONS_BUFSIZE, the function reserve_sfa_size() does
not return -EMSGSIZE as expected, but it allocates MAX_ACTIONS_BUFSIZE
bytes increasing actions_len by req_size. This can then lead to an OOB
write access, especially when further actions need to be copied.
Fix it by rearranging the flow action size check.
KASAN splat below:
==================================================================
BUG: KASAN: slab-out-of-bounds in reserve_sfa_size+0x1ba/0x380 [openvswitch]
Write of size 65360 at addr ffff888147e4001c by task handler15/836
CPU: 1 PID: 836 Comm: handler15 Not tainted 5.18.0-rc1+ #27
...
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x5a
print_report.cold+0x5e/0x5db
? __lock_text_start+0x8/0x8
? reserve_sfa_size+0x1ba/0x380 [openvswitch]
kasan_report+0xb5/0x130
? reserve_sfa_size+0x1ba/0x380 [openvswitch]
kasan_check_range+0xf5/0x1d0
memcpy+0x39/0x60
reserve_sfa_size+0x1ba/0x380 [openvswitch]
__add_action+0x24/0x120 [openvswitch]
ovs_nla_add_action+0xe/0x20 [openvswitch]
ovs_ct_copy_action+0x29d/0x1130 [openvswitch]
? __kernel_text_address+0xe/0x30
? unwind_get_return_address+0x56/0xa0
? create_prof_cpu_mask+0x20/0x20
? ovs_ct_verify+0xf0/0xf0 [openvswitch]
? prep_compound_page+0x198/0x2a0
? __kasan_check_byte+0x10/0x40
? kasan_unpoison+0x40/0x70
? ksize+0x44/0x60
? reserve_sfa_size+0x75/0x380 [openvswitch]
__ovs_nla_copy_actions+0xc26/0x2070 [openvswitch]
? __zone_watermark_ok+0x420/0x420
? validate_set.constprop.0+0xc90/0xc90 [openvswitch]
? __alloc_pages+0x1a9/0x3e0
? __alloc_pages_slowpath.constprop.0+0x1da0/0x1da0
? unwind_next_frame+0x991/0x1e40
? __mod_node_page_state+0x99/0x120
? __mod_lruvec_page_state+0x2e3/0x470
? __kasan_kmalloc_large+0x90/0xe0
ovs_nla_copy_actions+0x1b4/0x2c0 [openvswitch]
ovs_flow_cmd_new+0x3cd/0xb10 [openvswitch]
...
Cc: stable@vger.kernel.org
Fixes: f28cd2af22 ("openvswitch: fix flow actions reallocation")
Signed-off-by: Paolo Valerio <pvalerio@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While parsing user-provided actions, openvswitch module may dynamically
allocate memory and store pointers in the internal copy of the actions.
So this memory has to be freed while destroying the actions.
Currently there are only two such actions: ct() and set(). However,
there are many actions that can hold nested lists of actions and
ovs_nla_free_flow_actions() just jumps over them leaking the memory.
For example, removal of the flow with the following actions will lead
to a leak of the memory allocated by nf_ct_tmpl_alloc():
actions:clone(ct(commit),0)
Non-freed set() action may also leak the 'dst' structure for the
tunnel info including device references.
Under certain conditions with a high rate of flow rotation that may
cause significant memory leak problem (2MB per second in reporter's
case). The problem is also hard to mitigate, because the user doesn't
have direct control over the datapath flows generated by OVS.
Fix that by iterating over all the nested actions and freeing
everything that needs to be freed recursively.
New build time assertion should protect us from this problem if new
actions will be added in the future.
Unfortunately, openvswitch module doesn't use NLA_F_NESTED, so all
attributes has to be explicitly checked. sample() and clone() actions
are mixing extra attributes into the user-provided action list. That
prevents some code generalization too.
Fixes: 34ae932a40 ("openvswitch: Make tunnel set action attach a metadata dst")
Link: https://mail.openvswitch.org/pipermail/ovs-dev/2022-March/392922.html
Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'OVS_CLONE_ATTR_EXEC' is an internal attribute that is used for
performance optimization inside the kernel. It's added by the kernel
while parsing user-provided actions and should not be sent during the
flow dump as it's not part of the uAPI.
The issue doesn't cause any significant problems to the ovs-vswitchd
process, because reported actions are not really used in the
application lifecycle and only supposed to be shown to a human via
ovs-dpctl flow dump. However, the action list is still incorrect
and causes the following error if the user wants to look at the
datapath flows:
# ovs-dpctl add-dp system@ovs-system
# ovs-dpctl add-flow "<flow match>" "clone(ct(commit),0)"
# ovs-dpctl dump-flows
<flow match>, packets:0, bytes:0, used:never,
actions:clone(bad length 4, expected -1 for: action0(01 00 00 00),
ct(commit),0)
With the fix:
# ovs-dpctl dump-flows
<flow match>, packets:0, bytes:0, used:never,
actions:clone(ct(commit),0)
Additionally fixed an incorrect attribute name in the comment.
Fixes: b233504033 ("openvswitch: kernel datapath clone action")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/20220404104150.2865736-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When hitting the recirculation limit, the kernel would currently log
something like this:
[ 58.586597] openvswitch: ovs-system: deferred action limit reached, drop recirc action
Which isn't all that useful to debug as we only have the interface name
to go on but can't track it down to a specific flow.
With this change, we now instead get:
[ 58.586597] openvswitch: ovs-system: deferred action limit reached, drop recirc action (recirc_id=0x9e)
Which can now be correlated with the flow entries from OVS.
Suggested-by: Frode Nordahl <frode.nordahl@canonical.com>
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Tested-by: Stephane Graber <stgraber@ubuntu.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/20220330194244.3476544-1-stgraber@ubuntu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
IPv6 nd target mask was not getting populated in flow dump.
In the function __ovs_nla_put_key the icmp code mask field was checked
instead of icmp code key field to classify the flow as neighbour discovery.
ufid:bdfbe3e5-60c2-43b0-a5ff-dfcac1c37328, recirc_id(0),dp_hash(0/0),
skb_priority(0/0),in_port(ovs-nm1),skb_mark(0/0),ct_state(0/0),
ct_zone(0/0),ct_mark(0/0),ct_label(0/0),
eth(src=00:00:00:00:00:00/00:00:00:00:00:00,
dst=00:00:00:00:00:00/00:00:00:00:00:00),
eth_type(0x86dd),
ipv6(src=::/::,dst=::/::,label=0/0,proto=58,tclass=0/0,hlimit=0/0,frag=no),
icmpv6(type=135,code=0),
nd(target=2001::2/::,
sll=00:00:00:00:00:00/00:00:00:00:00:00,
tll=00:00:00:00:00:00/00:00:00:00:00:00),
packets:10, bytes:860, used:0.504s, dp:ovs, actions:ovs-nm2
Fixes: e64457191a (openvswitch: Restructure datapath.c and flow.c)
Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Link: https://lore.kernel.org/r/20220328054148.3057-1-martinvarghesenokia@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
