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authorXin Long <lucien.xin@gmail.com>2020-11-14 08:22:53 +0300
committerJakub Kicinski <kuba@kernel.org>2020-11-14 22:57:12 +0300
commit057a10fa1f73d745c8e69aa54ab147715f5630ae (patch)
tree6c7fbfcf99c197c9aa931b1180fb77bede0e8c77
parent65b422d9b61ba12c08150784e8012fa1892ad03e (diff)
downloadlinux-057a10fa1f73d745c8e69aa54ab147715f5630ae.tar.xz
sctp: change to hold/put transport for proto_unreach_timer
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> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Link: https://lore.kernel.org/r/102788809b554958b13b95d33440f5448113b8d6.1605331373.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/sctp/input.c4
-rw-r--r--net/sctp/sm_sideeffect.c4
-rw-r--r--net/sctp/transport.c2
3 files changed, 5 insertions, 5 deletions
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 55d4fc6f371d..d508f6f3dd08 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 813d30767204..0948f14ce221 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 806af58f4375..60fcf31cdcfb 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);
}