linux-stable.git/net/ipv6, branch v5.4.161

udp6: allow SO_MARK ctrl msg to affect routing

2021-11-17T08:48:40+00:00

[ Upstream commit 42dcfd850e514b229d616a53dec06d0f2533217c ]

Commit c6af0c227a22 ("ip: support SO_MARK cmsg")
added propagation of SO_MARK from cmsg to skb->mark.
For IPv4 and raw sockets the mark also affects route
lookup, but in case of IPv6 the flow info is
initialized before cmsg is parsed.

Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg")
Reported-and-tested-by: Xintong Hu 
Signed-off-by: Jakub Kicinski 
Reviewed-by: David Ahern 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

gre/sit: Don't generate link-local addr if addr_gen_mode is IN6_ADDR_GEN_MODE_NONE

2021-11-17T08:48:32+00:00

[ Upstream commit 61e18ce7348bfefb5688a8bcd4b4d6b37c0f9b2a ]

When addr_gen_mode is set to IN6_ADDR_GEN_MODE_NONE, the link-local addr
should not be generated. But it isn't the case for GRE (as well as GRE6)
and SIT tunnels. Make it so that tunnels consider the addr_gen_mode,
especially for IN6_ADDR_GEN_MODE_NONE.

Do this in add_v4_addrs() to cover both GRE and SIT only if the addr
scope is link.

Signed-off-by: Stephen Suryaputra 
Acked-by: Antonio Quartulli 
Link: https://lore.kernel.org/r/20211020200618.467342-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv6: use siphash in rt6_exception_hash()

2021-11-02T18:46:11+00:00

commit 4785305c05b25a242e5314cc821f54ade4c18810 upstream.

A group of security researchers brought to our attention
the weakness of hash function used in rt6_exception_hash()

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Following patch deals with IPv4.

Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet 
Reported-by: Keyu Man 
Cc: Wei Wang 
Cc: Martin KaFai Lau 
Acked-by: Wei Wang 
Signed-off-by: David S. Miller 
[OP: adjusted context for 5.4 stable]
Signed-off-by: Ovidiu Panait 
Signed-off-by: Greg Kroah-Hartman

netfilter: ip6_tables: zero-initialize fragment offset

2021-10-17T08:42:33+00:00

[ Upstream commit 310e2d43c3ad429c1fba4b175806cf1f55ed73a6 ]

ip6tables only sets the `IP6T_F_PROTO` flag on a rule if a protocol is
specified (`-p tcp`, for example).  However, if the flag is not set,
`ip6_packet_match` doesn't call `ipv6_find_hdr` for the skb, in which
case the fragment offset is left uninitialized and a garbage value is
passed to each matcher.

Signed-off-by: Jeremy Sowden 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

net: prefer socket bound to interface when not in VRF

2021-10-13T08:08:20+00:00

[ Upstream commit 8d6c414cd2fb74aa6812e9bfec6178f8246c4f3a ]

The commit 6da5b0f027a8 ("net: ensure unbound datagram socket to be
chosen when not in a VRF") modified compute_score() so that a device
match is always made, not just in the case of an l3mdev skb, then
increments the score also for unbound sockets. This ensures that
sockets bound to an l3mdev are never selected when not in a VRF.
But as unbound and bound sockets are now scored equally, this results
in the last opened socket being selected if there are matches in the
default VRF for an unbound socket and a socket bound to a dev that is
not an l3mdev. However, handling prior to this commit was to always
select the bound socket in this case. Reinstate this handling by
incrementing the score only for bound sockets. The required isolation
due to choosing between an unbound socket and a socket bound to an
l3mdev remains in place due to the device match always being made.
The same approach is taken for compute_score() for stream sockets.

Fixes: 6da5b0f027a8 ("net: ensure unbound datagram socket to be chosen when not in a VRF")
Fixes: e78190581aff ("net: ensure unbound stream socket to be chosen when not in a VRF")
Signed-off-by: Mike Manning 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/cf0a8523-b362-1edf-ee78-eef63cbbb428@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: udp: annotate data race around udp_sk(sk)->corkflag

2021-10-06T13:42:37+00:00

commit a9f5970767d11eadc805d5283f202612c7ba1f59 upstream.

up->corkflag field can be read or written without any lock.
Annotate accesses to avoid possible syzbot/KCSAN reports.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv4: Fix rtnexthop len when RTA_FLOW is present

2021-10-06T13:42:33+00:00

[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ]

Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop()
to get the length of rtnexthop correct.

Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info")
Signed-off-by: Xiao Liang 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv6: delay fib6_sernum increase in fib6_add

2021-09-30T08:09:24+00:00

[ Upstream commit e87b5052271e39d62337ade531992b7e5d8c2cfa ]

only increase fib6_sernum in net namespace after add fib6_info
successfully.

Signed-off-by: zhang kai 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

netfilter: socket: icmp6: fix use-after-scope

2021-09-22T10:26:45+00:00

[ Upstream commit 730affed24bffcd1eebd5903171960f5ff9f1f22 ]

Bug reported by KASAN:

BUG: KASAN: use-after-scope in inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
Call Trace:
(...)
inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
(...)
nf_sk_lookup_slow_v6 (net/ipv6/netfilter/nf_socket_ipv6.c:91
net/ipv6/netfilter/nf_socket_ipv6.c:146)

It seems that this bug has already been fixed by Eric Dumazet in the
past in:
commit 78296c97ca1f ("netfilter: xt_socket: fix a stack corruption bug")

But a variant of the same issue has been introduced in
commit d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")

`daddr` and `saddr` potentially hold a reference to ipv6_var that is no
longer in scope when the call to `nf_socket_get_sock_v6` is made.

Fixes: d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")
Acked-by: Matthieu Baerts 
Signed-off-by: Benjamin Hesmans 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipv6: make exception cache less predictible

2021-09-15T07:47:37+00:00

[ Upstream commit a00df2caffed3883c341d5685f830434312e4a43 ]

Even after commit 4785305c05b2 ("ipv6: use siphash in rt6_exception_hash()"),
an attacker can still use brute force to learn some secrets from a victim
linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
we do not expect this to be a problem.

Following patch is dealing with the same issue in IPv4.

Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet 
Reported-by: Keyu Man 
Cc: Wei Wang 
Cc: Martin KaFai Lau 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin