linux-stable.git/include/net/sctp/structs.h, branch linux-6.3.y

sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop

2023-02-23T20:59:40+00:00

With this refcnt added in sctp_stream_priorities, we don't need to
traverse all streams to check if the prio is used by other streams
when freeing one stream's prio in sctp_sched_prio_free_sid(). This
can avoid a nested loop (up to 65535 * 65535), which may cause a
stuck as Ying reported:

    watchdog: BUG: soft lockup - CPU#23 stuck for 26s! [ksoftirqd/23:136]
    Call Trace:
     
     sctp_sched_prio_free_sid+0xab/0x100 [sctp]
     sctp_stream_free_ext+0x64/0xa0 [sctp]
     sctp_stream_free+0x31/0x50 [sctp]
     sctp_association_free+0xa5/0x200 [sctp]

Note that it doesn't need to use refcount_t type for this counter,
as its accessing is always protected under the sock lock.

v1->v2:
 - add a check in sctp_sched_prio_set to avoid the possible prio_head
   refcnt overflow.

Fixes: 9ed7bfc79542 ("sctp: fix memory leak in sctp_stream_outq_migrate()")
Reported-by: Ying Xu 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: Xin Long 
Link: https://lore.kernel.org/r/825eb0c905cb864991eba335f4a2b780e543f06b.1677085641.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski

sctp: add dif and sdif check in asoc and ep lookup

2022-11-18T11:42:54+00:00

This patch at first adds a pernet global l3mdev_accept to decide if it
accepts the packets from a l3mdev when a SCTP socket doesn't bind to
any interface. It's set to 1 to avoid any possible incompatible issue,
and in next patch, a sysctl will be introduced to allow to change it.

Then similar to inet/udp_sk_bound_dev_eq(), sctp_sk_bound_dev_eq() is
added to check either dif or sdif is equal to sk_bound_dev_if, and to
check sid is 0 or l3mdev_accept is 1 if sk_bound_dev_if is not set.
This function is used to match a association or a endpoint, namely
called by sctp_addrs_lookup_transport() and sctp_endpoint_is_match().
All functions that needs updating are:

sctp_rcv():
  asoc:
  __sctp_rcv_lookup()
    __sctp_lookup_association() -> sctp_addrs_lookup_transport()
    __sctp_rcv_lookup_harder()
      __sctp_rcv_init_lookup()
         __sctp_lookup_association() -> sctp_addrs_lookup_transport()
      __sctp_rcv_walk_lookup()
         __sctp_rcv_asconf_lookup()
           __sctp_lookup_association() -> sctp_addrs_lookup_transport()

  ep:
  __sctp_rcv_lookup_endpoint() -> sctp_endpoint_is_match()

sctp_connect():
  sctp_endpoint_is_peeled_off()
    __sctp_lookup_association()
      sctp_has_association()
        sctp_lookup_association()
          __sctp_lookup_association() -> sctp_addrs_lookup_transport()

sctp_diag_dump_one():
  sctp_transport_lookup_process() -> sctp_addrs_lookup_transport()

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: add skb_sdif in struct sctp_af

2022-11-18T11:42:54+00:00

Add skb_sdif function in struct sctp_af to get the enslaved device
for both ipv4 and ipv6 when adding SCTP VRF support in sctp_rcv in
the next patch.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-12-30T20:12:12+00:00

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
  commit 077cdda764c7 ("net/mlx5e: TC, Fix memory leak with rules with internal port")
  commit 31108d142f36 ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  commit 4390c6edc0fb ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  https://lore.kernel.org/all/20211229065352.30178-1-saeed@kernel.org/

net/smc/smc_wr.c
  commit 49dc9013e34b ("net/smc: Use the bitmap API when applicable")
  commit 349d43127dac ("net/smc: fix kernel panic caused by race of smc_sock")
  bitmap_zero()/memset() is removed by the fix

Signed-off-by: Jakub Kicinski

sctp: use call_rcu to free endpoint

2021-12-25T17:13:37+00:00

This patch is to delay the endpoint free by calling call_rcu() to fix
another use-after-free issue in sctp_sock_dump():

  BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20
  Call Trace:
    __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218
    lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
    __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
    _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
    spin_lock_bh include/linux/spinlock.h:334 [inline]
    __lock_sock+0x203/0x350 net/core/sock.c:2253
    lock_sock_nested+0xfe/0x120 net/core/sock.c:2774
    lock_sock include/net/sock.h:1492 [inline]
    sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324
    sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5091
    sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527
    __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049
    inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065
    netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244
    __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352
    netlink_dump_start include/linux/netlink.h:216 [inline]
    inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170
    __sock_diag_cmd net/core/sock_diag.c:232 [inline]
    sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263
    netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477
    sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274

This issue occurs when asoc is peeled off and the old sk is freed after
getting it by asoc->base.sk and before calling lock_sock(sk).

To prevent the sk free, as a holder of the sk, ep should be alive when
calling lock_sock(). This patch uses call_rcu() and moves sock_put and
ep free into sctp_endpoint_destroy_rcu(), so that it's safe to try to
hold the ep under rcu_read_lock in sctp_transport_traverse_process().

If sctp_endpoint_hold() returns true, it means this ep is still alive
and we have held it and can continue to dump it; If it returns false,
it means this ep is dead and can be freed after rcu_read_unlock, and
we should skip it.

In sctp_sock_dump(), after locking the sk, if this ep is different from
tsp->asoc->ep, it means during this dumping, this asoc was peeled off
before calling lock_sock(), and the sk should be skipped; If this ep is
the same with tsp->asoc->ep, it means no peeloff happens on this asoc,
and due to lock_sock, no peeloff will happen either until release_sock.

Note that delaying endpoint free won't delay the port release, as the
port release happens in sctp_endpoint_destroy() before calling call_rcu().
Also, freeing endpoint by call_rcu() makes it safe to access the sk by
asoc->base.sk in sctp_assocs_seq_show() and sctp_rcv().

Thanks Jones to bring this issue up.

v1->v2:
  - improve the changelog.
  - add kfree(ep) into sctp_endpoint_destroy_rcu(), as Jakub noticed.

Reported-by: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com
Reported-by: Lee Jones 
Fixes: d25adbeb0cdb ("sctp: fix an use-after-free issue in sctp_sock_dump")
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: move hlist_node and hashent out of sctp_ep_common

2021-12-23T11:15:30+00:00

Struct sctp_ep_common is included in both asoc and ep, but hlist_node
and hashent are only needed by ep after asoc_hashtable was dropped by
Commit b5eff7128366 ("sctp: drop the old assoc hashtable of sctp").

So it is better to move hlist_node and hashent from sctp_ep_common to
sctp_endpoint, and it saves some space for each asoc.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: make the raise timer more simple and accurate

2021-11-26T05:00:45+00:00

Currently, the probe timer is reused as the raise timer when PLPMTUD is in
the Search Complete state. raise_count was introduced to count how many
times the probe timer has timed out. When raise_count reaches to 30, the
raise timer handler will be triggered.

During the whole processing above, the timer keeps timing out every probe_
interval. It is a waste for the Search Complete state, as the raise timer
only needs to time out after 30 * probe_interval.

Since the raise timer and probe timer are never used at the same time, it
is no need to keep probe timer 'alive' in the Search Complete state. This
patch to introduce sctp_transport_reset_raise_timer() to start the timer
as the raise timer when entering the Search Complete state. When entering
the other states, sctp_transport_reset_probe_timer() will still be called
to reset the timer to the probe timer.

raise_count can be removed from sctp_transport as no need to count probe
timer timeout for raise timer timeout. last_rtx_chunks can be removed as
sctp_transport_reset_probe_timer() can be called in the place where asoc
rtx_data_chunks is changed.

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Link: https://lore.kernel.org/r/edb0e48988ea85997488478b705b11ddc1ba724a.1637781974.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski

security: pass asoc to sctp_assoc_request and sctp_sk_clone

2021-11-03T11:09:20+00:00

This patch is to move secid and peer_secid from endpoint to association,
and pass asoc to sctp_assoc_request and sctp_sk_clone instead of ep. As
ep is the local endpoint and asoc represents a connection, and in SCTP
one sk/ep could have multiple asoc/connection, saving secid/peer_secid
for new asoc will overwrite the old asoc's.

Note that since asoc can be passed as NULL, security_sctp_assoc_request()
is moved to the place right after the new_asoc is created in
sctp_sf_do_5_1B_init() and sctp_sf_do_unexpected_init().

v1->v2:
  - fix the description of selinux_netlbl_skbuff_setsid(), as Jakub noticed.
  - fix the annotation in selinux_sctp_assoc_request(), as Richard Noticed.

Fixes: 72e89f50084c ("security: Add support for SCTP security hooks")
Reported-by: Prashanth Prahlad 
Reviewed-by: Richard Haines 
Tested-by: Richard Haines 
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: send pmtu probe only if packet loss in Search Complete state

2021-07-25T22:06:02+00:00

This patch is to introduce last_rtx_chunks into sctp_transport to detect
if there's any packet retransmission/loss happened by checking against
asoc's rtx_data_chunks in sctp_transport_pl_send().

If there is, namely, transport->last_rtx_chunks != asoc->rtx_data_chunks,
the pmtu probe will be sent out. Otherwise, increment the pl.raise_count
and return when it's in Search Complete state.

With this patch, if in Search Complete state, which is a long period, it
doesn't need to keep probing the current pmtu unless there's data packet
loss. This will save quite some traffic.

v1->v2:
  - add the missing Fixes tag.

Fixes: 0dac127c0557 ("sctp: do black hole detection in search complete state")
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: improve the code for pmtu probe send and recv update

2021-07-25T22:06:02+00:00

This patch does 3 things:

  - make sctp_transport_pl_send() and sctp_transport_pl_recv()
    return bool type to decide if more probe is needed to send.

  - pr_debug() only when probe is really needed to send.

  - count pl.raise_count in sctp_transport_pl_send() instead of
    sctp_transport_pl_recv(), and it's only incremented for the
    1st probe for the same size.

These are preparations for the next patch to make probes happen
only when there's packet loss in Search Complete state.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller