kernel/linux.git/net/sctp/sm_sideeffect.c, branch v6.12.80

sctp: handle invalid error codes without calling BUG()

2023-06-12T08:36:27+00:00

The sctp_sf_eat_auth() function is supposed to return enum sctp_disposition values but if the call to sctp_ulpevent_make_authkey() fails, it returns -ENOMEM. This results in calling BUG() inside the sctp_side_effects() function. Calling BUG() is an over reaction and not helpful. Call WARN_ON_ONCE() instead. This code predates git. Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller

sctp: delete the nested flexible array variable

2023-04-21T07:19:29+00:00

This patch deletes the flexible-array variable[] from the structure sctp_sackhdr and sctp_errhdr to avoid some sparse warnings: # make C=2 CF="-Wflexible-array-nested" M=./net/sctp/ net/sctp/sm_statefuns.c: note: in included file (through include/net/sctp/structs.h, include/net/sctp/sctp.h): ./include/linux/sctp.h:451:28: warning: nested flexible array ./include/linux/sctp.h:393:29: warning: nested flexible array Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: check asoc strreset_chunk in sctp_generate_reconf_event

2022-04-23T21:34:17+00:00

A null pointer reference issue can be triggered when the response of a stream reconf request arrives after the timer is triggered, such as: send Incoming SSN Reset Request ---> CPU0: reconf timer is triggered, go to the handler code before hold sk lock <--- reply with Outgoing SSN Reset Request CPU1: process Outgoing SSN Reset Request, and set asoc->strreset_chunk to NULL CPU0: continue the handler code, hold sk lock, and try to hold asoc->strreset_chunk, crash! In Ying Xu's testing, the call trace is: [ ] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ ] RIP: 0010:sctp_chunk_hold+0xe/0x40 [sctp] [ ] Call Trace: [ ] [ ] sctp_sf_send_reconf+0x2c/0x100 [sctp] [ ] sctp_do_sm+0xa4/0x220 [sctp] [ ] sctp_generate_reconf_event+0xbd/0xe0 [sctp] [ ] call_timer_fn+0x26/0x130 This patch is to fix it by returning from the timer handler if asoc strreset_chunk is already set to NULL. Fixes: 7b9438de0cd4 ("sctp: add stream reconf timer") Reported-by: Ying Xu Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: add the probe timer in transport for PLPMTUD

2021-06-22T18:28:52+00:00

There are 3 timers described in rfc8899#section-5.1.1: PROBE_TIMER, PMTU_RAISE_TIMER, CONFIRMATION_TIMER This patches adds a 'probe_timer' in transport, and it works as either PROBE_TIMER or PMTU_RAISE_TIMER. At most time, it works as PROBE_TIMER and expires every a 'probe_interval' time to send the HB probe packet. When transport pl enters COMPLETE state, it works as PMTU_RAISE_TIMER and expires in 'probe_interval * 30' time to go back to SEARCH state and do searching again. SCTP HB is an acknowledged packet, CONFIRMATION_TIMER is not needed. The timer will start when transport pl enters BASE state and stop when it enters DISABLED state. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: do asoc update earlier in sctp_sf_do_dupcook_b

2021-04-30T22:06:34+00:00

The same thing should be done for sctp_sf_do_dupcook_b(). Meanwhile, SCTP_CMD_UPDATE_ASSOC cmd can be removed. v1->v2: - Fix the return value in sctp_sf_do_assoc_update(). Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: change to hold/put transport for proto_unreach_timer

2020-11-14T19:57:12+00:00

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

2020-11-02T23:03:25+00:00

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

2020-08-23T22:36:59+00:00

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

2020-05-19T22:46:52+00:00

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

2020-01-09T20:13:43+00:00

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