| Message ID | 102788809b554958b13b95d33440f5448113b8d6.1605331373.git.lucien.xin@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [PATCHv2,net] sctp: change to hold/put transport for proto_unreach_timer | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net |
| netdev/subject_prefix | success | Link |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 2 this patch: 2 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 40 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 2 this patch: 2 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
On Sat, Nov 14, 2020 at 01:22:53PM +0800, Xin Long wrote: > A call trace was found in Hangbin's Codenomicon testing with debug kernel: > ... > > 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 <liuhangbin@gmail.com> > Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
On Sat, 14 Nov 2020 10:40:23 -0300 Marcelo Ricardo Leitner wrote: > On Sat, Nov 14, 2020 at 01:22:53PM +0800, Xin Long wrote: > > A call trace was found in Hangbin's Codenomicon testing with debug kernel: > > > ... > > > > 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 <liuhangbin@gmail.com> > > Signed-off-by: Xin Long <lucien.xin@gmail.com> > > Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Applied, thanks!
diff --git a/net/sctp/input.c b/net/sctp/input.c index 55d4fc6..d508f6f 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -449,7 +449,7 @@ void sctp_icmp_proto_unreachable(struct sock *sk, else { if (!mod_timer(&t->proto_unreach_timer, jiffies + (HZ/20))) - sctp_association_hold(asoc); + sctp_transport_hold(t); } } else { struct net *net = sock_net(sk); @@ -458,7 +458,7 @@ void sctp_icmp_proto_unreachable(struct sock *sk, "encountered!\n", __func__); if (del_timer(&t->proto_unreach_timer)) - sctp_association_put(asoc); + sctp_transport_put(t); sctp_do_sm(net, SCTP_EVENT_T_OTHER, SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index 813d307..0948f14 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -419,7 +419,7 @@ void sctp_generate_proto_unreach_event(struct timer_list *t) /* Try again later. */ if (!mod_timer(&transport->proto_unreach_timer, jiffies + (HZ/20))) - sctp_association_hold(asoc); + sctp_transport_hold(transport); goto out_unlock; } @@ -435,7 +435,7 @@ void sctp_generate_proto_unreach_event(struct timer_list *t) out_unlock: bh_unlock_sock(sk); - sctp_association_put(asoc); + sctp_transport_put(transport); } /* Handle the timeout of the RE-CONFIG timer. */ diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 806af58..60fcf31 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -133,7 +133,7 @@ void sctp_transport_free(struct sctp_transport *transport) /* Delete the ICMP proto unreachable timer if it's active. */ if (del_timer(&transport->proto_unreach_timer)) - sctp_association_put(transport->asoc); + sctp_transport_put(transport); sctp_transport_put(transport); }
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] <IRQ> [ 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] </IRQ> 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 <liuhangbin@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> --- net/sctp/input.c | 4 ++-- net/sctp/sm_sideeffect.c | 4 ++-- net/sctp/transport.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-)