linux-toradex.git/net/ipv6, branch v6.15-rc7

gre: Fix again IPv6 link-local address generation.

2025-05-06T01:08:14+00:00

Use addrconf_addr_gen() to generate IPv6 link-local addresses on GRE
devices in most cases and fall back to using add_v4_addrs() only in
case the GRE configuration is incompatible with addrconf_addr_gen().

GRE used to use addrconf_addr_gen() until commit e5dd729460ca ("ip/ip6_gre:
use the same logic as SIT interfaces when computing v6LL address")
restricted this use to gretap and ip6gretap devices, and created
add_v4_addrs() (borrowed from SIT) for non-Ethernet GRE ones.

The original problem came when commit 9af28511be10 ("addrconf: refuse
isatap eui64 for INADDR_ANY") made __ipv6_isatap_ifid() fail when its
addr parameter was 0. The commit says that this would create an invalid
address, however, I couldn't find any RFC saying that the generated
interface identifier would be wrong. Anyway, since gre over IPv4
devices pass their local tunnel address to __ipv6_isatap_ifid(), that
commit broke their IPv6 link-local address generation when the local
address was unspecified.

Then commit e5dd729460ca ("ip/ip6_gre: use the same logic as SIT
interfaces when computing v6LL address") tried to fix that case by
defining add_v4_addrs() and calling it to generate the IPv6 link-local
address instead of using addrconf_addr_gen() (apart for gretap and
ip6gretap devices, which would still use the regular
addrconf_addr_gen(), since they have a MAC address).

That broke several use cases because add_v4_addrs() isn't properly
integrated into the rest of IPv6 Neighbor Discovery code. Several of
these shortcomings have been fixed over time, but add_v4_addrs()
remains broken on several aspects. In particular, it doesn't send any
Router Sollicitations, so the SLAAC process doesn't start until the
interface receives a Router Advertisement. Also, add_v4_addrs() mostly
ignores the address generation mode of the interface
(/proc/sys/net/ipv6/conf/*/addr_gen_mode), thus breaking the
IN6_ADDR_GEN_MODE_RANDOM and IN6_ADDR_GEN_MODE_STABLE_PRIVACY cases.

Fix the situation by using add_v4_addrs() only in the specific scenario
where the normal method would fail. That is, for interfaces that have
all of the following characteristics:

  * run over IPv4,
  * transport IP packets directly, not Ethernet (that is, not gretap
    interfaces),
  * tunnel endpoint is INADDR_ANY (that is, 0),
  * device address generation mode is EUI64.

In all other cases, revert back to the regular addrconf_addr_gen().

Also, remove the special case for ip6gre interfaces in add_v4_addrs(),
since ip6gre devices now always use addrconf_addr_gen() instead.

Note:
  This patch was originally applied as commit 183185a18ff9 ("gre: Fix
  IPv6 link-local address generation."). However, it was then reverted
  by commit fc486c2d060f ("Revert "gre: Fix IPv6 link-local address
  generation."") because it uncovered another bug that ended up
  breaking net/forwarding/ip6gre_custom_multipath_hash.sh. That other
  bug has now been fixed by commit 4d0ab3a6885e ("ipv6: Start path
  selection from the first nexthop"). Therefore we can now revive this
  GRE patch (no changes since original commit 183185a18ff9 ("gre: Fix
  IPv6 link-local address generation.").

Fixes: e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address")
Signed-off-by: Guillaume Nault 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/a88cc5c4811af36007645d610c95102dccb360a6.1746225214.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski

net: use sock_gen_put() when sk_state is TCP_TIME_WAIT

2025-05-01T14:00:19+00:00

It is possible for a pointer of type struct inet_timewait_sock to be
returned from the functions __inet_lookup_established() and
__inet6_lookup_established(). This can cause a crash when the
returned pointer is of type struct inet_timewait_sock and
sock_put() is called on it. The following is a crash call stack that
shows sk->sk_wmem_alloc being accessed in sk_free() during the call to
sock_put() on a struct inet_timewait_sock pointer. To avoid this issue,
use sock_gen_put() instead of sock_put() when sk->sk_state
is TCP_TIME_WAIT.

mrdump.ko        ipanic() + 120
vmlinux          notifier_call_chain(nr_to_call=-1, nr_calls=0) + 132
vmlinux          atomic_notifier_call_chain(val=0) + 56
vmlinux          panic() + 344
vmlinux          add_taint() + 164
vmlinux          end_report() + 136
vmlinux          kasan_report(size=0) + 236
vmlinux          report_tag_fault() + 16
vmlinux          do_tag_recovery() + 16
vmlinux          __do_kernel_fault() + 88
vmlinux          do_bad_area() + 28
vmlinux          do_tag_check_fault() + 60
vmlinux          do_mem_abort() + 80
vmlinux          el1_abort() + 56
vmlinux          el1h_64_sync_handler() + 124
vmlinux        > 0xFFFFFFC080011294()
vmlinux          __lse_atomic_fetch_add_release(v=0xF2FFFF82A896087C)
vmlinux          __lse_atomic_fetch_sub_release(v=0xF2FFFF82A896087C)
vmlinux          arch_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C)
+ 8
vmlinux          raw_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C)
+ 8
vmlinux          atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8
vmlinux          __refcount_sub_and_test(i=1, r=0xF2FFFF82A896087C,
oldp=0) + 8
vmlinux          __refcount_dec_and_test(r=0xF2FFFF82A896087C, oldp=0) + 8
vmlinux          refcount_dec_and_test(r=0xF2FFFF82A896087C) + 8
vmlinux          sk_free(sk=0xF2FFFF82A8960700) + 28
vmlinux          sock_put() + 48
vmlinux          tcp6_check_fraglist_gro() + 236
vmlinux          tcp6_gro_receive() + 624
vmlinux          ipv6_gro_receive() + 912
vmlinux          dev_gro_receive() + 1116
vmlinux          napi_gro_receive() + 196
ccmni.ko         ccmni_rx_callback() + 208
ccmni.ko         ccmni_queue_recv_skb() + 388
ccci_dpmaif.ko   dpmaif_rxq_push_thread() + 1088
vmlinux          kthread() + 268
vmlinux          0xFFFFFFC08001F30C()

Fixes: c9d1d23e5239 ("net: add heuristic for enabling TCP fraglist GRO")
Signed-off-by: Jibin Zhang 
Signed-off-by: Shiming Cheng 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20250429020412.14163-1-shiming.cheng@mediatek.com
Signed-off-by: Jakub Kicinski

ipv6: add exception routes to GC list in rt6_insert_exception

2025-04-11T03:09:05+00:00

Commit 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list
of routes.") introduced a separated list for managing route expiration via
the GC timer.

However, it missed adding exception routes (created by ip6_rt_update_pmtu()
and rt6_do_redirect()) to this GC list. As a result, these exceptions were
never considered for expiration and removal, leading to stale entries
persisting in the routing table.

This patch fixes the issue by calling fib6_add_gc_list() in
rt6_insert_exception(), ensuring that exception routes are properly tracked
and garbage collected when expired.

Fixes: 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list of routes.")
Reported-by: Jianlin Shi 
Signed-off-by: Xin Long 
Reviewed-by: David Ahern 
Link: https://patch.msgid.link/837e7506ffb63f47faa2b05d9b85481aad28e1a4.1744134377.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski

Merge tag 'net-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-04-10T15:52:18+00:00

Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter.

  Current release - regressions:

    - core: hold instance lock during NETDEV_CHANGE

    - rtnetlink: fix bad unlock balance in do_setlink()

    - ipv6:
       - fix null-ptr-deref in addrconf_add_ifaddr()
       - align behavior across nexthops during path selection

  Previous releases - regressions:

    - sctp: prevent transport UaF in sendmsg

    - mptcp: only inc MPJoinAckHMacFailure for HMAC failures

  Previous releases - always broken:

    - sched:
       - make ->qlen_notify() idempotent
       - ensure sufficient space when sending filter netlink notifications
       - sch_sfq: really don't allow 1 packet limit

    - netfilter: fix incorrect avx2 match of 5th field octet

    - tls: explicitly disallow disconnect

    - eth: octeontx2-pf: fix VF root node parent queue priority"

* tag 'net-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (38 commits)
  ethtool: cmis_cdb: Fix incorrect read / write length extension
  selftests: netfilter: add test case for recent mismatch bug
  nft_set_pipapo: fix incorrect avx2 match of 5th field octet
  net: ppp: Add bound checking for skb data on ppp_sync_txmung
  net: Fix null-ptr-deref by sock_lock_init_class_and_name() and rmmod.
  ipv6: Align behavior across nexthops during path selection
  net: phy: allow MDIO bus PM ops to start/stop state machine for phylink-controlled PHY
  net: phy: move phy_link_change() prior to mdio_bus_phy_may_suspend()
  selftests/tc-testing: sfq: check that a derived limit of 1 is rejected
  net_sched: sch_sfq: move the limit validation
  net_sched: sch_sfq: use a temporary work area for validating configuration
  net: libwx: handle page_pool_dev_alloc_pages error
  selftests: mptcp: validate MPJoin HMacFailure counters
  mptcp: only inc MPJoinAckHMacFailure for HMAC failures
  rtnetlink: Fix bad unlock balance in do_setlink().
  net: ethtool: Don't call .cleanup_data when prepare_data fails
  tc: Ensure we have enough buffer space when sending filter netlink notifications
  net: libwx: Fix the wrong Rx descriptor field
  octeontx2-pf: qos: fix VF root node parent queue index
  selftests: tls: check that disconnect does nothing
  ...

ipv6: Align behavior across nexthops during path selection

2025-04-10T01:00:06+00:00

A nexthop is only chosen when the calculated multipath hash falls in the
nexthop's hash region (i.e., the hash is smaller than the nexthop's hash
threshold) and when the nexthop is assigned a non-negative score by
rt6_score_route().

Commit 4d0ab3a6885e ("ipv6: Start path selection from the first
nexthop") introduced an unintentional difference between the first
nexthop and the rest when the score is negative.

When the first nexthop matches, but has a negative score, the code will
currently evaluate subsequent nexthops until one is found with a
non-negative score. On the other hand, when a different nexthop matches,
but has a negative score, the code will fallback to the nexthop with
which the selection started ('match').

Align the behavior across all nexthops and fallback to 'match' when the
first nexthop matches, but has a negative score.

Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N")
Fixes: 4d0ab3a6885e ("ipv6: Start path selection from the first nexthop")
Reported-by: Willem de Bruijn 
Closes: https://lore.kernel.org/netdev/67efef607bc41_1ddca82948c@willemb.c.googlers.com.notmuch/
Signed-off-by: Ido Schimmel 
Reviewed-by: Willem de Bruijn 
Reviewed-by: David Ahern 
Link: https://patch.msgid.link/20250408084316.243559-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski

ipv6: Fix null-ptr-deref in addrconf_add_ifaddr().

2025-04-07T18:02:19+00:00

The cited commit placed netdev_lock_ops() just after __dev_get_by_index()
in addrconf_add_ifaddr(), where dev could be NULL as reported. [0]

Let's call netdev_lock_ops() only when dev is not NULL.

[0]:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000198: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000cc0-0x0000000000000cc7]
CPU: 3 UID: 0 PID: 12032 Comm: syz.0.15 Not tainted 6.14.0-13408-g9f867ba24d36 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:addrconf_add_ifaddr (./include/net/netdev_lock.h:30 ./include/net/netdev_lock.h:41 net/ipv6/addrconf.c:3157)
Code: 8b b4 24 94 00 00 00 4c 89 ef e8 7e 4c 2f ff 4c 8d b0 c5 0c 00 00 48 89 c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 4c 89 f2 83 e2 07 38 d0 7f 08 80
RSP: 0018:ffffc90015b0faa0 EFLAGS: 00010213
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000198 RSI: ffffffff893162f2 RDI: ffff888078cb0338
RBP: ffffc90015b0fbb0 R08: 0000000000000000 R09: fffffbfff20cbbe2
R10: ffffc90015b0faa0 R11: 0000000000000000 R12: 1ffff92002b61f54
R13: ffff888078cb0000 R14: 0000000000000cc5 R15: ffff888078cb0000
FS: 00007f92559ed640(0000) GS:ffff8882a8659000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f92559ecfc8 CR3: 000000001c39e000 CR4: 00000000000006f0
Call Trace:
 
 inet6_ioctl (net/ipv6/af_inet6.c:580)
 sock_do_ioctl (net/socket.c:1196)
 sock_ioctl (net/socket.c:1314)
 __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:906 fs/ioctl.c:892 fs/ioctl.c:892)
 do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130
RIP: 0033:0x7f9254b9c62d
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff f8
RSP: 002b:00007f92559ecf98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9254d65f80 RCX: 00007f9254b9c62d
RDX: 0000000020000040 RSI: 0000000000008916 RDI: 0000000000000003
RBP: 00007f9254c264d3 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9254d65f80 R15: 00007f92559cd000
 
Modules linked in:

Fixes: 8965c160b8f7 ("net: use netif_disable_lro in ipv6_add_dev")
Reported-by: syzkaller 
Reported-by: Hui Guo 
Closes: https://lore.kernel.org/netdev/CAHOo4gK+tdU1B14Kh6tg-tNPqnQ1qGLfinONFVC43vmgEPnXXw@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima 
Acked-by: Stanislav Fomichev 
Link: https://patch.msgid.link/20250406035755.69238-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

ipv6: Do not consider link down nexthops in path selection

2025-04-04T14:30:07+00:00

Nexthops whose link is down are not supposed to be considered during
path selection when the "ignore_routes_with_linkdown" sysctl is set.
This is done by assigning them a negative region boundary.

However, when comparing the computed hash (unsigned) with the region
boundary (signed), the negative region boundary is treated as unsigned,
resulting in incorrect nexthop selection.

Fix by treating the computed hash as signed. Note that the computed hash
is always in range of [0, 2^31 - 1].

Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N")
Signed-off-by: Ido Schimmel 
Reviewed-by: Willem de Bruijn 
Link: https://patch.msgid.link/20250402114224.293392-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski

ipv6: Start path selection from the first nexthop

2025-04-04T14:30:07+00:00

Cited commit transitioned IPv6 path selection to use hash-threshold
instead of modulo-N. With hash-threshold, each nexthop is assigned a
region boundary in the multipath hash function's output space and a
nexthop is chosen if the calculated hash is smaller than the nexthop's
region boundary.

Hash-threshold does not work correctly if path selection does not start
with the first nexthop. For example, if fib6_select_path() is always
passed the last nexthop in the group, then it will always be chosen
because its region boundary covers the entire hash function's output
space.

Fix this by starting the selection process from the first nexthop and do
not consider nexthops for which rt6_score_route() provided a negative
score.

Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N")
Reported-by: Stanislav Fomichev 
Closes: https://lore.kernel.org/netdev/Z9RIyKZDNoka53EO@mini-arch/
Signed-off-by: Ido Schimmel 
Link: https://patch.msgid.link/20250402114224.293392-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski

net: use netif_disable_lro in ipv6_add_dev

2025-04-03T22:32:08+00:00

ipv6_add_dev might call dev_disable_lro which unconditionally grabs
instance lock, so it will deadlock during NETDEV_REGISTER. Switch
to netif_disable_lro.

Make sure all callers hold the instance lock as well.

Cc: Cosmin Ratiu 
Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev 
Link: https://patch.msgid.link/20250401163452.622454-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski