[PATCH v2] rxrpc: Fix use-after-free in rxrpc_destroy_all_peers()
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Marco Elver
Sep 7, 2026, 6:23:45 PM (2 days ago) Sep 7
to el...@google.com, David Howells, Marc Dionne, David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni, Simon Horman, linu...@lists.infradead.org, net...@vger.kernel.org, linux-...@vger.kernel.org, kasa...@googlegroups.com, syzkall...@googlegroups.com, syzbot+c876ad...@syzkaller.appspotmail.com
During network namespace teardown, rxrpc_destroy_all_peers() iterates over
the rxnet->peer_hash table to print leaked peers without holding
rxnet->peer_hash_lock. If concurrent activity or asynchronous teardown
drops the last reference to a peer, __rxrpc_put_peer() unlinks the peer
from rxnet->peer_hash and frees it via kfree_rcu(). Without locking,
traversal can follow an unlinked peer or race with RCU reclamation,
triggering a KASAN slab-use-after-free.
BUG: KASAN: slab-use-after-free in rxrpc_destroy_all_peers+0xcc/0x150
net/rxrpc/peer_object.c:461
Read of size 8 at addr ffff88811089e420 by task kworker/u8:1/13
Call Trace:
<TASK>
rxrpc_destroy_all_peers+0xcc/0x150 net/rxrpc/peer_object.c:461
rxrpc_exit_net+0x7f/0xc0 net/rxrpc/net_ns.c:114
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
cleanup_net+0x572/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
To fix the slab-use-after-free, acquire rxnet->peer_hash_lock with
spin_lock_bh() while iterating over rxnet->peer_hash in
rxrpc_destroy_all_peers().
Additionally, split netns teardown by implementing .pre_exit in
rxrpc_net_ops to clean up calls, connections, and keepalive work. This
ensures in-flight references are released before cleanup_net() executes
its intermediate synchronize_rcu(), so that peer and local endpoint leak
checks in rxrpc_exit_net() run only after deferred RCU releases complete,
avoiding spurious leak warnings.
Fixes: 17226f124038 ("rxrpc: Fix leak of rxrpc_peer objects")
Reported-by: syzbot+c876ad...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c876adfab6362679008c
Link: https://syzkaller.appspot.com/ai_job?id=7fecbeb2-cd9b-4ca2-8149-48663e20b153
Signed-off-by: Marco Elver <el...@google.com>
---
v2:
* Split teardown and use .pre_exit instead of rcu_barrier() (Eric).
---
net/rxrpc/net_ns.c | 23 +++++++++++++++--------
net/rxrpc/peer_object.c | 8 ++++++++
2 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
index 9a9834145e81..169116735366 100644
--- a/net/rxrpc/net_ns.c
+++ b/net/rxrpc/net_ns.c
@@ -97,10 +97,7 @@ static __net_init int rxrpc_init_net(struct net *net)
return ret;
}
-/*
- * Clean up a per-network namespace record.
- */
-static __net_exit void rxrpc_exit_net(struct net *net)
+static __net_exit void rxrpc_pre_exit_net(struct net *net)
{
struct rxrpc_net *rxnet = rxrpc_net(net);
@@ -111,14 +108,24 @@ static __net_exit void rxrpc_exit_net(struct net *net)
timer_delete_sync(&rxnet->peer_keepalive_timer);
rxrpc_destroy_all_calls(rxnet);
rxrpc_destroy_all_connections(rxnet);
+}
+
+/*
+ * Clean up a per-network namespace record.
+ */
+static __net_exit void rxrpc_exit_net(struct net *net)
+{
+ struct rxrpc_net *rxnet = rxrpc_net(net);
+
rxrpc_destroy_all_peers(rxnet);
rxrpc_destroy_all_locals(rxnet);
proc_remove(rxnet->proc_net);
}
struct pernet_operations rxrpc_net_ops = {
- .init = rxrpc_init_net,
- .exit = rxrpc_exit_net,
- .id = &rxrpc_net_id,
- .size = sizeof(struct rxrpc_net),
+ .init = rxrpc_init_net,
+ .pre_exit = rxrpc_pre_exit_net,
+ .exit = rxrpc_exit_net,
+ .id = &rxrpc_net_id,
+ .size = sizeof(struct rxrpc_net),
};
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index fa9a406e1168..faa2983638b2 100644
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -454,6 +454,12 @@ void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
struct rxrpc_peer *peer;
int i;
+ /*
+ * Prevent use-after-free if a peer is concurrently unlinked from the
+ * hash table and freed via RCU during iteration.
+ */
+ spin_lock_bh(&rxnet->peer_hash_lock);
+
for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
if (hlist_empty(&rxnet->peer_hash[i]))
continue;
@@ -465,6 +471,8 @@ void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
&peer->srx.transport);
}
}
+
+ spin_unlock_bh(&rxnet->peer_hash_lock);
}
/**
--
2.55.0.1003.g10538fe699-goog
the rxnet->peer_hash table to print leaked peers without holding
rxnet->peer_hash_lock. If concurrent activity or asynchronous teardown
drops the last reference to a peer, __rxrpc_put_peer() unlinks the peer
from rxnet->peer_hash and frees it via kfree_rcu(). Without locking,
traversal can follow an unlinked peer or race with RCU reclamation,
triggering a KASAN slab-use-after-free.
BUG: KASAN: slab-use-after-free in rxrpc_destroy_all_peers+0xcc/0x150
net/rxrpc/peer_object.c:461
Read of size 8 at addr ffff88811089e420 by task kworker/u8:1/13
Call Trace:
<TASK>
rxrpc_destroy_all_peers+0xcc/0x150 net/rxrpc/peer_object.c:461
rxrpc_exit_net+0x7f/0xc0 net/rxrpc/net_ns.c:114
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
cleanup_net+0x572/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
To fix the slab-use-after-free, acquire rxnet->peer_hash_lock with
spin_lock_bh() while iterating over rxnet->peer_hash in
rxrpc_destroy_all_peers().
Additionally, split netns teardown by implementing .pre_exit in
rxrpc_net_ops to clean up calls, connections, and keepalive work. This
ensures in-flight references are released before cleanup_net() executes
its intermediate synchronize_rcu(), so that peer and local endpoint leak
checks in rxrpc_exit_net() run only after deferred RCU releases complete,
avoiding spurious leak warnings.
Fixes: 17226f124038 ("rxrpc: Fix leak of rxrpc_peer objects")
Reported-by: syzbot+c876ad...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c876adfab6362679008c
Link: https://syzkaller.appspot.com/ai_job?id=7fecbeb2-cd9b-4ca2-8149-48663e20b153
Signed-off-by: Marco Elver <el...@google.com>
---
v2:
* Split teardown and use .pre_exit instead of rcu_barrier() (Eric).
---
net/rxrpc/net_ns.c | 23 +++++++++++++++--------
net/rxrpc/peer_object.c | 8 ++++++++
2 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
index 9a9834145e81..169116735366 100644
--- a/net/rxrpc/net_ns.c
+++ b/net/rxrpc/net_ns.c
@@ -97,10 +97,7 @@ static __net_init int rxrpc_init_net(struct net *net)
return ret;
}
-/*
- * Clean up a per-network namespace record.
- */
-static __net_exit void rxrpc_exit_net(struct net *net)
+static __net_exit void rxrpc_pre_exit_net(struct net *net)
{
struct rxrpc_net *rxnet = rxrpc_net(net);
@@ -111,14 +108,24 @@ static __net_exit void rxrpc_exit_net(struct net *net)
timer_delete_sync(&rxnet->peer_keepalive_timer);
rxrpc_destroy_all_calls(rxnet);
rxrpc_destroy_all_connections(rxnet);
+}
+
+/*
+ * Clean up a per-network namespace record.
+ */
+static __net_exit void rxrpc_exit_net(struct net *net)
+{
+ struct rxrpc_net *rxnet = rxrpc_net(net);
+
rxrpc_destroy_all_peers(rxnet);
rxrpc_destroy_all_locals(rxnet);
proc_remove(rxnet->proc_net);
}
struct pernet_operations rxrpc_net_ops = {
- .init = rxrpc_init_net,
- .exit = rxrpc_exit_net,
- .id = &rxrpc_net_id,
- .size = sizeof(struct rxrpc_net),
+ .init = rxrpc_init_net,
+ .pre_exit = rxrpc_pre_exit_net,
+ .exit = rxrpc_exit_net,
+ .id = &rxrpc_net_id,
+ .size = sizeof(struct rxrpc_net),
};
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index fa9a406e1168..faa2983638b2 100644
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -454,6 +454,12 @@ void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
struct rxrpc_peer *peer;
int i;
+ /*
+ * Prevent use-after-free if a peer is concurrently unlinked from the
+ * hash table and freed via RCU during iteration.
+ */
+ spin_lock_bh(&rxnet->peer_hash_lock);
+
for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
if (hlist_empty(&rxnet->peer_hash[i]))
continue;
@@ -465,6 +471,8 @@ void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
&peer->srx.transport);
}
}
+
+ spin_unlock_bh(&rxnet->peer_hash_lock);
}
/**
--
2.55.0.1003.g10538fe699-goog
syzbot ci
Sep 8, 2026, 4:11:55 AM (2 days ago) Sep 8
to da...@davemloft.net, dhow...@redhat.com, edum...@google.com, el...@google.com, ho...@kernel.org, kasa...@googlegroups.com, ku...@kernel.org, linu...@lists.infradead.org, linux-...@vger.kernel.org, marc....@auristor.com, net...@vger.kernel.org, pab...@redhat.com, syz...@syzkaller.appspotmail.com, syzkall...@googlegroups.com, syz...@lists.linux.dev, syzkall...@googlegroups.com
syzbot ci has tested the following series
[v2] rxrpc: Fix use-after-free in rxrpc_destroy_all_peers()
https://lore.kernel.org/all/20260907222242....@google.com
* [PATCH v2] rxrpc: Fix use-after-free in rxrpc_destroy_all_peers()
and found the following issue:
INFO: task hung in rxrpc_destroy_all_calls
Full report is available here:
https://ci.syzbot.org/series/72f7714d-3fb8-4e04-aa6f-2891301ed056
***
INFO: task hung in rxrpc_destroy_all_calls
tree: net-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base: 31f961de2f90fbf52eb2d4e15b3eeaa09f9b4fc2
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/6dafa5c2-5fb1-49b9-b4e5-8877f26c5afd/config
syz repro: https://ci.syzbot.org/findings/4eb5795c-f73d-43ee-b3df-3291d8644727/syz_repro
INFO: task kworker/u8:2:5453 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2 state:D stack:26848 pid:5453 tgid:5453 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
rxrpc_destroy_all_calls+0x43d/0x560 net/rxrpc/call_object.c:756
rxrpc_pre_exit_net+0x6f/0x90 net/rxrpc/net_ns.c:109
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x17d/0x8d0 net/core/net_namespace.c:235
cleanup_net+0x572/0x810 net/core/net_namespace.c:706
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
locks held by kworker/u8:1/13: 4, last CPU#0:
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffff88823c624408 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933
#2: ffff88823c626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x904/0xed0 kernel/time/timer.c:1117
#3: ffffffff9abf4d30 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
locks held by pr/ttyS0/16: 2, last CPU#0:
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
#1: ffffffff9ad32098 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9ad32098 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by kworker/1:0/25: 3, on CPU#1:
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff88819efed250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0 drivers/net/netdevsim/fib.c:1490
locks held by khungtaskd/35: 1, last CPU#1:
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by getty/5425: 2, on CPU#0:
#0: ffff8881001f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:2/5453: 3, on CPU#1:
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90242108 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
locks held by kworker/0:6/5822: 3, on CPU#0:
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x6f/0x770 net/core/netdev_work.c:132
locks held by syz-executor/3546: 1, last CPU#0:
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz-executor/4305: 3, last CPU#0:
#0: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#0: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214
#1: ffff8881a15ace70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline]
#1: ffff8881a15ace70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#1: ffff8881a15ace70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: do_setlink+0x3d4/0x4670 net/core/rtnetlink.c:3176
#2: ffffffff90242048 (net_rwsem){++++}-{4:4}, at: wireless_nlevent_flush net/wireless/wext-core.c:350 [inline]
#2: ffffffff90242048 (net_rwsem){++++}-{4:4}, at: wext_netdev_notifier_call+0x28/0x110 net/wireless/wext-core.c:370
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:416
Code: b2 55 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cc 7b c5 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 4f 75 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000157900 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85720850 R12: dffffc0000000000
R13: 000000000000005b R14: ffffffff9ad320c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88818d6d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb361ed158 CR3: 00000001a3b52000 CR4: 00000000000006f0
Call Trace:
<TASK>
serial_port_out include/linux/serial_core.h:817 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3287 [inline]
__serial8250_console_fifo_write+0x1e6/0x3e0 drivers/tty/serial/8250/8250_port.c:3359
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 kernel/kthread.c:436
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syz...@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzk...@googlegroups.com.
To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.
Notes:
- The patch will be applied on top of the tested series (as an
incremental fix).
- To test a new version of the whole series, please send it directly
to syz...@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.
[v2] rxrpc: Fix use-after-free in rxrpc_destroy_all_peers()
https://lore.kernel.org/all/20260907222242....@google.com
* [PATCH v2] rxrpc: Fix use-after-free in rxrpc_destroy_all_peers()
and found the following issue:
INFO: task hung in rxrpc_destroy_all_calls
Full report is available here:
https://ci.syzbot.org/series/72f7714d-3fb8-4e04-aa6f-2891301ed056
***
INFO: task hung in rxrpc_destroy_all_calls
tree: net-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base: 31f961de2f90fbf52eb2d4e15b3eeaa09f9b4fc2
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/6dafa5c2-5fb1-49b9-b4e5-8877f26c5afd/config
syz repro: https://ci.syzbot.org/findings/4eb5795c-f73d-43ee-b3df-3291d8644727/syz_repro
INFO: task kworker/u8:2:5453 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2 state:D stack:26848 pid:5453 tgid:5453 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
rxrpc_destroy_all_calls+0x43d/0x560 net/rxrpc/call_object.c:756
rxrpc_pre_exit_net+0x6f/0x90 net/rxrpc/net_ns.c:109
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x17d/0x8d0 net/core/net_namespace.c:235
cleanup_net+0x572/0x810 net/core/net_namespace.c:706
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Showing all locks held in the system:
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
locks held by kworker/u8:1/13: 4, last CPU#0:
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888177a23940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffff88823c624408 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933
#2: ffff88823c626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x904/0xed0 kernel/time/timer.c:1117
#3: ffffffff9abf4d30 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
locks held by pr/ttyS0/16: 2, last CPU#0:
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
#1: ffffffff9ad32098 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9ad32098 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by kworker/1:0/25: 3, on CPU#1:
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc900001f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff88819efed250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0 drivers/net/netdevsim/fib.c:1490
locks held by khungtaskd/35: 1, last CPU#1:
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by getty/5425: 2, on CPU#0:
#0: ffff8881001f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:2/5453: 3, on CPU#1:
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90003edfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90242108 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
locks held by kworker/0:6/5822: 3, on CPU#0:
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000388fc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x6f/0x770 net/core/netdev_work.c:132
locks held by syz-executor/3546: 1, last CPU#0:
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz-executor/4305: 3, last CPU#0:
#0: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#0: ffffffff90250960 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214
#1: ffff8881a15ace70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline]
#1: ffff8881a15ace70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#1: ffff8881a15ace70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: do_setlink+0x3d4/0x4670 net/core/rtnetlink.c:3176
#2: ffffffff90242048 (net_rwsem){++++}-{4:4}, at: wireless_nlevent_flush net/wireless/wext-core.c:350 [inline]
#2: ffffffff90242048 (net_rwsem){++++}-{4:4}, at: wext_netdev_notifier_call+0x28/0x110 net/wireless/wext-core.c:370
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 1 to CPUs 0:
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:416
Code: b2 55 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cc 7b c5 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 4f 75 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000157900 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85720850 R12: dffffc0000000000
R13: 000000000000005b R14: ffffffff9ad320c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88818d6d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb361ed158 CR3: 00000001a3b52000 CR4: 00000000000006f0
Call Trace:
<TASK>
serial_port_out include/linux/serial_core.h:817 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3287 [inline]
__serial8250_console_fifo_write+0x1e6/0x3e0 drivers/tty/serial/8250/8250_port.c:3359
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
***
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syz...@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzk...@googlegroups.com.
To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.
Notes:
- The patch will be applied on top of the tested series (as an
incremental fix).
- To test a new version of the whole series, please send it directly
to syz...@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.
Marco Elver
Sep 8, 2026, 7:53:32 AM (2 days ago) Sep 8
to el...@google.com, David Howells, Marc Dionne, David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni, Simon Horman, linu...@lists.infradead.org, net...@vger.kernel.org, linux-...@vger.kernel.org, kasa...@googlegroups.com, syzkall...@googlegroups.com, syzbot+c876ad...@syzkaller.appspotmail.com
During network namespace teardown, rxrpc_destroy_all_peers() iterates over
the rxnet->peer_hash table to print leaked peers without holding
rxnet->peer_hash_lock. If concurrent activity drops the last reference to
the rxnet->peer_hash table to print leaked peers without holding
a peer, __rxrpc_put_peer() unlinks the peer from rxnet->peer_hash under
rxnet->peer_hash_lock and frees it via kfree_rcu(). Without locking,
traversal can race with hash unlinking and RCU reclamation, triggering a
KASAN slab-use-after-free.
BUG: KASAN: slab-use-after-free in rxrpc_destroy_all_peers+0xcc/0x150
net/rxrpc/peer_object.c:461
Read of size 8 at addr ffff88811089e420 by task kworker/u8:1/13
Call Trace:
<TASK>
rxrpc_destroy_all_peers+0xcc/0x150 net/rxrpc/peer_object.c:461
rxrpc_exit_net+0x7f/0xc0 net/rxrpc/net_ns.c:114
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
cleanup_net+0x572/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
BUG: KASAN: slab-use-after-free in rxrpc_destroy_all_peers+0xcc/0x150
net/rxrpc/peer_object.c:461
Read of size 8 at addr ffff88811089e420 by task kworker/u8:1/13
Call Trace:
<TASK>
rxrpc_destroy_all_peers+0xcc/0x150 net/rxrpc/peer_object.c:461
rxrpc_exit_net+0x7f/0xc0 net/rxrpc/net_ns.c:114
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
cleanup_net+0x572/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Fix the slab-use-after-free by acquiring rxnet->peer_hash_lock with
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
spin_lock_bh() while iterating over rxnet->peer_hash in
rxrpc_destroy_all_peers().
rxrpc_destroy_all_peers().
Fixes: 17226f124038 ("rxrpc: Fix leak of rxrpc_peer objects")
Reported-by: syzbot+c876ad...@syzkaller.appspotmail.com
Assisted-by: Gemini:gemini-3.6-flash Gemini:gemini-3.1-pro-preview syzbot
Reported-by: syzbot+c876ad...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c876adfab6362679008c
Link: https://syzkaller.appspot.com/ai_job?id=7fecbeb2-cd9b-4ca2-8149-48663e20b153
Signed-off-by: Marco Elver <el...@google.com>
---
v3:
Link: https://syzkaller.appspot.com/ai_job?id=7fecbeb2-cd9b-4ca2-8149-48663e20b153
Signed-off-by: Marco Elver <el...@google.com>
---
* syzbot reported "INFO: task hung in rxrpc_destroy_all_calls" on v2:
Drop .pre_exit split. rxrpc_destroy_all_calls() blocks in
wait_var_event() on RCU call freeing; executing this in .pre_exit
under pernet_ops_rwsem deadlocks netns cleanup before
synchronize_rcu() and device teardown can run.
v2:
* Split teardown and use .pre_exit instead of rcu_barrier() (Eric).
---
1 file changed, 8 insertions(+)
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