| Message ID | 7cb07ff74acd144f14a4467c7dddd12a940fbf52.1605259104.git.lucien.xin@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [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, 32 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 |
Hi, On Fri, Nov 13, 2020 at 05:18:24PM +0800, Xin Long wrote: ... > diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c > index 813d307..0a51150 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; > } > The chunk above covers the socket busy case, but for the normal cases it also needs: @@ -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(asoc); } /* 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); Btw, quite noticeable on the above list of timers that only this timer was using a reference on the asoc. Seems we're good now, then. :-) Marcelo
On Fri, Nov 13, 2020 at 8:35 PM Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> wrote: > > Hi, > > On Fri, Nov 13, 2020 at 05:18:24PM +0800, Xin Long wrote: > ... > > diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c > > index 813d307..0a51150 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; > > } > > > > The chunk above covers the socket busy case, but for the normal cases > it also needs: > > @@ -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(asoc); > } yeah, right, posted v2. Thanks. > > /* 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); > > Btw, quite noticeable on the above list of timers that only this timer > was using a reference on the asoc. Seems we're good now, then. :-) > correct! :D
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..0a51150 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; } 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. 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 | 2 +- net/sctp/transport.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-)