linux.git/net/netfilter/nfnetlink_queue.c, branch v6.11 Linux kernel source tree netfilter: nf_queue: drop packets with cloned unconfirmed conntracks 2024-08-14T21:37:23+00:00 Florian Westphal fw@strlen.de 2024-08-07T19:28:41+00:00 7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb Conntrack assumes an unconfirmed entry (not yet committed to global hash table) has a refcount of 1 and is not visible to other cores. With multicast forwarding this assumption breaks down because such skbs get cloned after being picked up, i.e. ct->use refcount is > 1. Likewise, bridge netfilter will clone broad/mutlicast frames and all frames in case they need to be flood-forwarded during learning phase. For ip multicast forwarding or plain bridge flood-forward this will "work" because packets don't leave softirq and are implicitly serialized. With nfqueue this no longer holds true, the packets get queued and can be reinjected in arbitrary ways. Disable this feature, I see no other solution. After this patch, nfqueue cannot queue packets except the last multicast/broadcast packet. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
Conntrack assumes an unconfirmed entry (not yet committed to global hash
table) has a refcount of 1 and is not visible to other cores.

With multicast forwarding this assumption breaks down because such
skbs get cloned after being picked up, i.e.  ct->use refcount is > 1.

Likewise, bridge netfilter will clone broad/mutlicast frames and
all frames in case they need to be flood-forwarded during learning
phase.

For ip multicast forwarding or plain bridge flood-forward this will
"work" because packets don't leave softirq and are implicitly
serialized.

With nfqueue this no longer holds true, the packets get queued
and can be reinjected in arbitrary ways.

Disable this feature, I see no other solution.

After this patch, nfqueue cannot queue packets except the last
multicast/broadcast packet.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nfnetlink_queue: drop bogus WARN_ON 2024-07-11T09:26:33+00:00 Florian Westphal fw@strlen.de 2024-07-09T00:02:26+00:00 631a4b3ddc7831b20442c59c28b0476d0704c9af Happens when rules get flushed/deleted while packet is out, so remove this WARN_ON. This WARN exists in one form or another since v4.14, no need to backport this to older releases, hence use a more recent fixes tag. Fixes: 3f8019688894 ("netfilter: move nf_reinject into nfnetlink_queue modules") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202407081453.11ac0f63-lkp@intel.com Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
Happens when rules get flushed/deleted while packet is out, so remove
this WARN_ON.

This WARN exists in one form or another since v4.14, no need to backport
this to older releases, hence use a more recent fixes tag.

Fixes: 3f8019688894 ("netfilter: move nf_reinject into nfnetlink_queue modules")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202407081453.11ac0f63-lkp@intel.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nfnetlink_queue: acquire rcu_read_lock() in instance_destroy_rcu() 2024-05-20T09:38:42+00:00 Eric Dumazet edumazet@google.com 2024-05-15T13:23:39+00:00 dc21c6cc3d6986d938efbf95de62473982c98dec syzbot reported that nf_reinject() could be called without rcu_read_lock() : WARNING: suspicious RCU usage 6.9.0-rc7-syzkaller-02060-g5c1672705a1a #0 Not tainted net/netfilter/nfnetlink_queue.c:263 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.4/13427: #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2190 [inline] #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_core+0xa86/0x1830 kernel/rcu/tree.c:2471 #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: nfqnl_flush net/netfilter/nfnetlink_queue.c:405 [inline] #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: instance_destroy_rcu+0x30/0x220 net/netfilter/nfnetlink_queue.c:172 stack backtrace: CPU: 0 PID: 13427 Comm: syz-executor.4 Not tainted 6.9.0-rc7-syzkaller-02060-g5c1672705a1a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 nf_reinject net/netfilter/nfnetlink_queue.c:323 [inline] nfqnl_reinject+0x6ec/0x1120 net/netfilter/nfnetlink_queue.c:397 nfqnl_flush net/netfilter/nfnetlink_queue.c:410 [inline] instance_destroy_rcu+0x1ae/0x220 net/netfilter/nfnetlink_queue.c:172 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 handle_softirqs+0x2d6/0x990 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 </IRQ> <TASK> Fixes: 9872bec773c2 ("[NETFILTER]: nfnetlink: use RCU for queue instances hash") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
syzbot reported that nf_reinject() could be called without rcu_read_lock() :

WARNING: suspicious RCU usage
6.9.0-rc7-syzkaller-02060-g5c1672705a1a #0 Not tainted

net/netfilter/nfnetlink_queue.c:263 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor.4/13427:
  #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
  #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2190 [inline]
  #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_core+0xa86/0x1830 kernel/rcu/tree.c:2471
  #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
  #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: nfqnl_flush net/netfilter/nfnetlink_queue.c:405 [inline]
  #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: instance_destroy_rcu+0x30/0x220 net/netfilter/nfnetlink_queue.c:172

stack backtrace:
CPU: 0 PID: 13427 Comm: syz-executor.4 Not tainted 6.9.0-rc7-syzkaller-02060-g5c1672705a1a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <IRQ>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712
  nf_reinject net/netfilter/nfnetlink_queue.c:323 [inline]
  nfqnl_reinject+0x6ec/0x1120 net/netfilter/nfnetlink_queue.c:397
  nfqnl_flush net/netfilter/nfnetlink_queue.c:410 [inline]
  instance_destroy_rcu+0x1ae/0x220 net/netfilter/nfnetlink_queue.c:172
  rcu_do_batch kernel/rcu/tree.c:2196 [inline]
  rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471
  handle_softirqs+0x2d6/0x990 kernel/softirq.c:554
  __do_softirq kernel/softirq.c:588 [inline]
  invoke_softirq kernel/softirq.c:428 [inline]
  __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
  irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>

Fixes: 9872bec773c2 ("[NETFILTER]: nfnetlink: use RCU for queue instances hash")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: move nf_reinject into nfnetlink_queue modules 2024-02-21T11:03:22+00:00 Florian Westphal fw@strlen.de 2024-02-14T13:41:02+00:00 3f801968889459ecae1eab524b039676e6eaa319 No need to keep this in the core, move it to the nfnetlink_queue module. nf_reroute is moved too, there were no other callers. Signed-off-by: Florian Westphal <fw@strlen.de> 
No need to keep this in the core, move it to the nfnetlink_queue module.
nf_reroute is moved too, there were no other callers.

Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: nfnetlink_queue: un-break NF_REPEAT 2024-02-08T11:10:19+00:00 Florian Westphal fw@strlen.de 2024-02-06T16:54:18+00:00 f82777e8ce6c039cdcacbcf1eb8619b99a20c06d Only override userspace verdict if the ct hook returns something other than ACCEPT. Else, this replaces NF_REPEAT (run all hooks again) with NF_ACCEPT (move to next hook). Fixes: 6291b3a67ad5 ("netfilter: conntrack: convert nf_conntrack_update to netfilter verdicts") Reported-by: l.6diay@passmail.com Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
Only override userspace verdict if the ct hook returns something
other than ACCEPT.

Else, this replaces NF_REPEAT (run all hooks again) with NF_ACCEPT
(move to next hook).

Fixes: 6291b3a67ad5 ("netfilter: conntrack: convert nf_conntrack_update to netfilter verdicts")
Reported-by: l.6diay@passmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: conntrack: convert nf_conntrack_update to netfilter verdicts 2023-10-18T08:26:43+00:00 Florian Westphal fw@strlen.de 2023-10-11T07:59:36+00:00 6291b3a67ad55102f163f6a636bc540e460f892d This function calls helpers that can return nf-verdicts, but then those get converted to -1/0 as thats what the caller expects. Theoretically NF_DROP could have an errno number set in the upper 24 bits of the return value. Or any of those helpers could return NF_STOLEN, which would result in use-after-free. This is fine as-is, the called functions don't do this yet. But its better to avoid possible future problems if the upcoming patchset to add NF_DROP_REASON() support gains further users, so remove the 0/-1 translation from the picture and pass the verdicts down to the caller. Signed-off-by: Florian Westphal <fw@strlen.de> 
This function calls helpers that can return nf-verdicts, but then
those get converted to -1/0 as thats what the caller expects.

Theoretically NF_DROP could have an errno number set in the upper 24
bits of the return value. Or any of those helpers could return
NF_STOLEN, which would result in use-after-free.

This is fine as-is, the called functions don't do this yet.

But its better to avoid possible future problems if the upcoming
patchset to add NF_DROP_REASON() support gains further users, so remove
the 0/-1 translation from the picture and pass the verdicts down to
the caller.

Signed-off-by: Florian Westphal <fw@strlen.de>
net: move gso declarations and functions to their own files 2023-06-10T07:11:41+00:00 Eric Dumazet edumazet@google.com 2023-06-08T19:17:37+00:00 d457a0e329b0bfd3a1450e0b1a18cd2b47a25a08 Move declarations into include/net/gso.h and code into net/core/gso.c Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stanislav Fomichev <sdf@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Move declarations into include/net/gso.h and code into net/core/gso.c

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netfilter: nfnetlink_queue: enable classid socket info retrieval 2023-03-30T20:20:09+00:00 Eric Sage eric_sage@apple.com 2023-03-27T17:44:49+00:00 28c1b6df436819a7ed8a781835766e45139771a3 This enables associating a socket with a v1 net_cls cgroup. Useful for applying a per-cgroup policy when processing packets in userspace. Signed-off-by: Eric Sage <eric_sage@apple.com> Signed-off-by: Florian Westphal <fw@strlen.de> 
This enables associating a socket with a v1 net_cls cgroup. Useful for
applying a per-cgroup policy when processing packets in userspace.

Signed-off-by: Eric Sage <eric_sage@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: nf_queue: do not allow packet truncation below transport header offset 2022-07-26T19:12:42+00:00 Florian Westphal fw@strlen.de 2022-07-26T10:42:06+00:00 99a63d36cb3ed5ca3aa6fcb64cffbeaf3b0fb164 Domingo Dirutigliano and Nicola Guerrera report kernel panic when sending nf_queue verdict with 1-byte nfta_payload attribute. The IP/IPv6 stack pulls the IP(v6) header from the packet after the input hook. If user truncates the packet below the header size, this skb_pull() will result in a malformed skb (skb->len < 0). Fixes: 7af4cc3fa158 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink") Reported-by: Domingo Dirutigliano <pwnzer0tt1@proton.me> Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org> 
Domingo Dirutigliano and Nicola Guerrera report kernel panic when
sending nf_queue verdict with 1-byte nfta_payload attribute.

The IP/IPv6 stack pulls the IP(v6) header from the packet after the
input hook.

If user truncates the packet below the header size, this skb_pull() will
result in a malformed skb (skb->len < 0).

Fixes: 7af4cc3fa158 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink")
Reported-by: Domingo Dirutigliano <pwnzer0tt1@proton.me>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-03-03T19:55:12+00:00 Jakub Kicinski kuba@kernel.org 2022-03-03T19:55:12+00:00 80901bff812984624918d9d03f9286e3245ee9a5 net/batman-adv/hard-interface.c commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check") commit 6ee3c393eeb7 ("batman-adv: Demote batadv-on-batadv skip error message") https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/ net/smc/af_smc.c commit 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails") commit 462791bbfa35 ("net/smc: add sysctl interface for SMC") https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
net/batman-adv/hard-interface.c
  commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check")
  commit 6ee3c393eeb7 ("batman-adv: Demote batadv-on-batadv skip error message")
https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/

net/smc/af_smc.c
  commit 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails")
  commit 462791bbfa35 ("net/smc: add sysctl interface for SMC")
https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>