kernel.git/net/sctp/sm_sideeffect.c, branch linux-5.11.y

sctp: change to hold/put transport for proto_unreach_timer

2020-11-14T19:57:12Z

A call trace was found in Hangbin's Codenomicon testing with debug kernel: [ 2615.981988] ODEBUG: free active (active state 0) object type: timer_list hint: sctp_generate_proto_unreach_event+0x0/0x3a0 [sctp] [ 2615.995050] WARNING: CPU: 17 PID: 0 at lib/debugobjects.c:328 debug_print_object+0x199/0x2b0 [ 2616.095934] RIP: 0010:debug_print_object+0x199/0x2b0 [ 2616.191533] Call Trace: [ 2616.194265] [ 2616.202068] debug_check_no_obj_freed+0x25e/0x3f0 [ 2616.207336] slab_free_freelist_hook+0xeb/0x140 [ 2616.220971] kfree+0xd6/0x2c0 [ 2616.224293] rcu_do_batch+0x3bd/0xc70 [ 2616.243096] rcu_core+0x8b9/0xd00 [ 2616.256065] __do_softirq+0x23d/0xacd [ 2616.260166] irq_exit+0x236/0x2a0 [ 2616.263879] smp_apic_timer_interrupt+0x18d/0x620 [ 2616.269138] apic_timer_interrupt+0xf/0x20 [ 2616.273711] This is because it holds asoc when transport->proto_unreach_timer starts and puts asoc when the timer stops, and without holding transport the transport could be freed when the timer is still running. So fix it by holding/putting transport instead for proto_unreach_timer in transport, just like other timers in transport. v1->v2: - Also use sctp_transport_put() for the "out_unlock:" path in sctp_generate_proto_unreach_event(), as Marcelo noticed. Fixes: 50b5d6ad6382 ("sctp: Fix a race between ICMP protocol unreachable and connect()") Reported-by: Hangbin Liu Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Link: https://lore.kernel.org/r/102788809b554958b13b95d33440f5448113b8d6.1605331373.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

sctp: Fix COMM_LOST/CANT_STR_ASSOC err reporting on big-endian platforms

2020-11-02T23:03:25Z

Commit 978aa0474115 ("sctp: fix some type cast warnings introduced since very beginning")' broke err reading from sctp_arg, because it reads the value as 32-bit integer, although the value is stored as 16-bit integer. Later this value is passed to the userspace in 16-bit variable, thus the user always gets 0 on big-endian platforms. Fix it by reading the __u16 field of sctp_arg union, as reading err field would produce a sparse warning. Fixes: 978aa0474115 ("sctp: fix some type cast warnings introduced since very beginning") Signed-off-by: Petr Malat Acked-by: Marcelo Ricardo Leitner Link: https://lore.kernel.org/r/20201030132633.7045-1-oss@malat.biz Signed-off-by: Jakub Kicinski

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

sctp: Don't add the shutdown timer if its already been added

2020-05-19T22:46:52Z

This BUG halt was reported a while back, but the patch somehow got missed: PID: 2879 TASK: c16adaa0 CPU: 1 COMMAND: "sctpn" #0 [f418dd28] crash_kexec at c04a7d8c #1 [f418dd7c] oops_end at c0863e02 #2 [f418dd90] do_invalid_op at c040aaca #3 [f418de28] error_code (via invalid_op) at c08631a5 EAX: f34baac0 EBX: 00000090 ECX: f418deb0 EDX: f5542950 EBP: 00000000 DS: 007b ESI: f34ba800 ES: 007b EDI: f418dea0 GS: 00e0 CS: 0060 EIP: c046fa5e ERR: ffffffff EFLAGS: 00010286 #4 [f418de5c] add_timer at c046fa5e #5 [f418de68] sctp_do_sm at f8db8c77 [sctp] #6 [f418df30] sctp_primitive_SHUTDOWN at f8dcc1b5 [sctp] #7 [f418df48] inet_shutdown at c080baf9 #8 [f418df5c] sys_shutdown at c079eedf #9 [f418df70] sys_socketcall at c079fe88 EAX: ffffffda EBX: 0000000d ECX: bfceea90 EDX: 0937af98 DS: 007b ESI: 0000000c ES: 007b EDI: b7150ae4 SS: 007b ESP: bfceea7c EBP: bfceeaa8 GS: 0033 CS: 0073 EIP: b775c424 ERR: 00000066 EFLAGS: 00000282 It appears that the side effect that starts the shutdown timer was processed multiple times, which can happen as multiple paths can trigger it. This of course leads to the BUG halt in add_timer getting called. Fix seems pretty straightforward, just check before the timer is added if its already been started. If it has mod the timer instead to min(current expiration, new expiration) Its been tested but not confirmed to fix the problem, as the issue has only occured in production environments where test kernels are enjoined from being installed. It appears to be a sane fix to me though. Also, recentely, Jere found a reproducer posted on list to confirm that this resolves the issues Signed-off-by: Neil Horman CC: Vlad Yasevich CC: "David S. Miller" CC: jere.leppanen@nokia.com CC: marcelo.leitner@gmail.com CC: netdev@vger.kernel.org Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

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

2020-01-09T20:13:43Z

The ungrafting from PRIO bug fixes in net, when merged into net-next, merge cleanly but create a build failure. The resolution used here is from Petr Machata. Signed-off-by: David S. Miller

sctp: free cmd->obj.chunk for the unprocessed SCTP_CMD_REPLY

2020-01-06T21:28:37Z

This patch is to fix a memleak caused by no place to free cmd->obj.chunk for the unprocessed SCTP_CMD_REPLY. This issue occurs when failing to process a cmd while there're still SCTP_CMD_REPLY cmds on the cmd seq with an allocated chunk in cmd->obj.chunk. So fix it by freeing cmd->obj.chunk for each SCTP_CMD_REPLY cmd left on the cmd seq when any cmd returns error. While at it, also remove 'nomem' label. Reported-by: syzbot+107c4aff5f392bf1517f@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: get netns from asoc and ep base

2019-12-10T04:14:01Z

Commit 312434617cb1 ("sctp: cache netns in sctp_ep_common") set netns in asoc and ep base since they're created, and it will never change. It's a better way to get netns from asoc and ep base, comparing to calling sock_net(). This patch is to replace them. v1->v2: - no change. Suggested-by: Marcelo Ricardo Leitner Signed-off-by: Xin Long Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: add support for Primary Path Switchover

2019-11-08T22:18:32Z

This is a new feature defined in section 5 of rfc7829: "Primary Path Switchover". By introducing a new tunable parameter: Primary.Switchover.Max.Retrans (PSMR) The primary path will be changed to another active path when the path error counter on the old primary path exceeds PSMR, so that "the SCTP sender is allowed to continue data transmission on a new working path even when the old primary destination address becomes active again". This patch is to add this tunable parameter, 'ps_retrans' per netns, sock, asoc and transport. It also allows a user to change ps_retrans per netns by sysctl, and ps_retrans per sock/asoc/transport will be initialized with it. The check will be done in sctp_do_8_2_transport_strike() when this feature is enabled. Note this feature is disabled by initializing 'ps_retrans' per netns as 0xffff by default, and its value can't be less than 'pf_retrans' when changing by sysctl. v3->v4: - add define SCTP_PS_RETRANS_MAX 0xffff, and use it on extra2 of sysctl 'ps_retrans'. - add a new entry for ps_retrans on ip-sysctl.txt. Signed-off-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: use transport pf_retrans in sctp_do_8_2_transport_strike

2019-09-04T22:29:21Z

Transport should use its own pf_retrans to do the error_count check, instead of asoc's. Otherwise, it's meaningless to make pf_retrans per transport. Fixes: 5aa93bcf66f4 ("sctp: Implement quick failover draft from tsvwg") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: fix the transport error_count check

2019-08-14T02:08:20Z

As the annotation says in sctp_do_8_2_transport_strike(): "If the transport error count is greater than the pf_retrans threshold, and less than pathmaxrtx ..." It should be transport->error_count checked with pathmaxrxt, instead of asoc->pf_retrans. Fixes: 5aa93bcf66f4 ("sctp: Implement quick failover draft from tsvwg") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski