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tipc-discussion
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From: Hoang H. Le <hoa...@de...> - 2020-08-26 03:53:25
|
Syzbot has reported those issues as:
==================================================================
BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Thread 1's call trace:
[...]
kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
tipc_exit_net+0x24/0x270 net/tipc/core.c:112
[...]
Thread 2's call trace:
[...]
tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
has already been freed by Thread 1
tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
tipc_net_finalize net/tipc/net.c:141 [inline]
tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
[...]
==================================================================
BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1f0/0x31e lib/dump_stack.c:118
print_address_description+0x66/0x5a0 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report+0x132/0x1d0 mm/kasan/report.c:530
tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
[...]
Freed by task 14058:
save_stack mm/kasan/common.c:48 [inline]
set_track mm/kasan/common.c:56 [inline]
kasan_set_free_info mm/kasan/common.c:316 [inline]
__kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
__cache_free mm/slab.c:3426 [inline]
kfree+0x10a/0x220 mm/slab.c:3757
tipc_exit_net+0x29/0x50 net/tipc/core.c:113
ops_exit_list net/core/net_namespace.c:186 [inline]
cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Solution 1 (preferer):
Fix it by calling flush_scheduled_work() to make sure the
tipc_net_finalize_work() stopped before releasing bcbase object.
Solution 2:
Fix it by introducing a bit flag and returning if flag is zero
(object had already been freed)
Reported-by: syz...@sy...
Reported-by: syz...@sy...
Signed-off-by: Hoang Huu Le <hoa...@de...>
---
net/tipc/core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/tipc/core.c b/net/tipc/core.c
index 4f6dc74adf45..37d8695548cf 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -109,6 +109,11 @@ static void __net_exit tipc_exit_net(struct net *net)
{
tipc_detach_loopback(net);
tipc_net_stop(net);
+
+ /* Make sure the tipc_net_finalize_work stopped
+ * before releasing the resources.
+ */
+ flush_scheduled_work();
tipc_bcast_stop(net);
tipc_nametbl_stop(net);
tipc_sk_rht_destroy(net);
--
2.25.1
|
|
From: Hoang H. Le <hoa...@de...> - 2020-08-26 03:53:26
|
Syzbot has reported those issues as:
==================================================================
BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Thread 1's call trace:
[...]
kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
tipc_exit_net+0x24/0x270 net/tipc/core.c:112
[...]
Thread 2's call trace:
[...]
tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
has already been freed by Thread 1
tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
tipc_net_finalize net/tipc/net.c:141 [inline]
tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
[...]
==================================================================
BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1f0/0x31e lib/dump_stack.c:118
print_address_description+0x66/0x5a0 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report+0x132/0x1d0 mm/kasan/report.c:530
tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
[...]
Freed by task 14058:
save_stack mm/kasan/common.c:48 [inline]
set_track mm/kasan/common.c:56 [inline]
kasan_set_free_info mm/kasan/common.c:316 [inline]
__kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
__cache_free mm/slab.c:3426 [inline]
kfree+0x10a/0x220 mm/slab.c:3757
tipc_exit_net+0x29/0x50 net/tipc/core.c:113
ops_exit_list net/core/net_namespace.c:186 [inline]
cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Solution 1 (preferer):
Fix it by calling flush_scheduled_work() to make sure the
tipc_net_finalize_work() stopped before releasing bcbase object.
Solution 2:
Fix it by introducing a bit flag and returning if flag is zero
(object had already been freed)
Reported-by: syz...@sy...
Reported-by: syz...@sy...
Signed-off-by: Hoang Huu Le <hoa...@de...>
---
net/tipc/bcast.c | 1 +
net/tipc/core.c | 1 +
net/tipc/core.h | 1 +
net/tipc/net.c | 3 +++
4 files changed, 6 insertions(+)
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 940d176e0e87..56b624c8b6d4 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -718,6 +718,7 @@ void tipc_bcast_stop(struct net *net)
struct tipc_net *tn = net_generic(net, tipc_net_id);
synchronize_net();
+ clear_bit_unlock(0, &tn->net_exit_flag);
kfree(tn->bcbase);
kfree(tn->bcl);
}
diff --git a/net/tipc/core.c b/net/tipc/core.c
index 4f6dc74adf45..93ea7dc05bf2 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -60,6 +60,7 @@ static int __net_init tipc_init_net(struct net *net)
tn->trial_addr = 0;
tn->addr_trial_end = 0;
tn->capabilities = TIPC_NODE_CAPABILITIES;
+ test_and_set_bit_lock(0, &tn->net_exit_flag);
memset(tn->node_id, 0, sizeof(tn->node_id));
memset(tn->node_id_string, 0, sizeof(tn->node_id_string));
tn->mon_threshold = TIPC_DEF_MON_THRESHOLD;
diff --git a/net/tipc/core.h b/net/tipc/core.h
index 631d83c9705f..aa75882dd932 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -143,6 +143,7 @@ struct tipc_net {
/* TX crypto handler */
struct tipc_crypto *crypto_tx;
#endif
+ unsigned long net_exit_flag;
};
static inline struct tipc_net *tipc_net(struct net *net)
diff --git a/net/tipc/net.c b/net/tipc/net.c
index 85400e4242de..0dcbfcff5ad3 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -132,6 +132,9 @@ static void tipc_net_finalize(struct net *net, u32 addr)
{
struct tipc_net *tn = tipc_net(net);
+ if (unlikely(!test_bit(0, &tn->net_exit_flag)))
+ return;
+
if (cmpxchg(&tn->node_addr, 0, addr))
return;
tipc_set_node_addr(net, addr);
--
2.25.1
|
|
From: Jon M. <jm...@re...> - 2020-08-26 17:55:36
|
On 8/25/20 11:52 PM, Hoang Huu Le wrote:
> Syzbot has reported those issues as:
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
> Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
>
> CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
>
> Thread 1's call trace:
> [...]
> kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
> tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
> tipc_exit_net+0x24/0x270 net/tipc/core.c:112
> [...]
>
> Thread 2's call trace:
> [...]
> tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
> has already been freed by Thread 1
>
> tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
> tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
> tipc_net_finalize net/tipc/net.c:141 [inline]
> tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
> tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
> [...]
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
> CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x1f0/0x31e lib/dump_stack.c:118
> print_address_description+0x66/0x5a0 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report+0x132/0x1d0 mm/kasan/report.c:530
> tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
> tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> [...]
> Freed by task 14058:
> save_stack mm/kasan/common.c:48 [inline]
> set_track mm/kasan/common.c:56 [inline]
> kasan_set_free_info mm/kasan/common.c:316 [inline]
> __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
> __cache_free mm/slab.c:3426 [inline]
> kfree+0x10a/0x220 mm/slab.c:3757
> tipc_exit_net+0x29/0x50 net/tipc/core.c:113
> ops_exit_list net/core/net_namespace.c:186 [inline]
> cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
>
> Solution 1 (preferer):
> Fix it by calling flush_scheduled_work() to make sure the
> tipc_net_finalize_work() stopped before releasing bcbase object.
>
> Solution 2:
> Fix it by introducing a bit flag and returning if flag is zero
> (object had already been freed)
>
> Reported-by: syz...@sy...
> Reported-by: syz...@sy...
> Signed-off-by: Hoang Huu Le <hoa...@de...>
> ---
> net/tipc/core.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/net/tipc/core.c b/net/tipc/core.c
> index 4f6dc74adf45..37d8695548cf 100644
> --- a/net/tipc/core.c
> +++ b/net/tipc/core.c
> @@ -109,6 +109,11 @@ static void __net_exit tipc_exit_net(struct net *net)
> {
> tipc_detach_loopback(net);
> tipc_net_stop(net);
> +
> + /* Make sure the tipc_net_finalize_work stopped
> + * before releasing the resources.
> + */
> + flush_scheduled_work();
> tipc_bcast_stop(net);
> tipc_nametbl_stop(net);
> tipc_sk_rht_destroy(net);
Acked-by: Jon Maloy <jm...@re...>
|
|
From: Hoang H. Le <hoa...@de...> - 2020-08-27 02:39:56
|
Syzbot has reported those issues as:
==================================================================
BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Thread 1's call trace:
[...]
kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
tipc_exit_net+0x24/0x270 net/tipc/core.c:112
[...]
Thread 2's call trace:
[...]
tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
has already been freed by Thread 1
tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
tipc_net_finalize net/tipc/net.c:141 [inline]
tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
[...]
==================================================================
BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1f0/0x31e lib/dump_stack.c:118
print_address_description+0x66/0x5a0 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report+0x132/0x1d0 mm/kasan/report.c:530
tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
[...]
Freed by task 14058:
save_stack mm/kasan/common.c:48 [inline]
set_track mm/kasan/common.c:56 [inline]
kasan_set_free_info mm/kasan/common.c:316 [inline]
__kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
__cache_free mm/slab.c:3426 [inline]
kfree+0x10a/0x220 mm/slab.c:3757
tipc_exit_net+0x29/0x50 net/tipc/core.c:113
ops_exit_list net/core/net_namespace.c:186 [inline]
cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Fix it by calling flush_scheduled_work() to make sure the
tipc_net_finalize_work() stopped before releasing bcbase object.
Reported-by: syz...@sy...
Reported-by: syz...@sy...
Acked-by: Jon Maloy <jm...@re...>
Signed-off-by: Hoang Huu Le <hoa...@de...>
---
net/tipc/core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/tipc/core.c b/net/tipc/core.c
index 4f6dc74adf45..37d8695548cf 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -109,6 +109,11 @@ static void __net_exit tipc_exit_net(struct net *net)
{
tipc_detach_loopback(net);
tipc_net_stop(net);
+
+ /* Make sure the tipc_net_finalize_work stopped
+ * before releasing the resources.
+ */
+ flush_scheduled_work();
tipc_bcast_stop(net);
tipc_nametbl_stop(net);
tipc_sk_rht_destroy(net);
--
2.25.1
|
|
From: Hoang H. Le <hoa...@de...> - 2020-08-27 02:57:24
|
Syzbot has reported those issues as:
==================================================================
BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Thread 1's call trace:
[...]
kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
tipc_exit_net+0x24/0x270 net/tipc/core.c:112
[...]
Thread 2's call trace:
[...]
tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
has already been freed by Thread 1
tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
tipc_net_finalize net/tipc/net.c:141 [inline]
tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
[...]
==================================================================
BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1f0/0x31e lib/dump_stack.c:118
print_address_description+0x66/0x5a0 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report+0x132/0x1d0 mm/kasan/report.c:530
tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
[...]
Freed by task 14058:
save_stack mm/kasan/common.c:48 [inline]
set_track mm/kasan/common.c:56 [inline]
kasan_set_free_info mm/kasan/common.c:316 [inline]
__kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
__cache_free mm/slab.c:3426 [inline]
kfree+0x10a/0x220 mm/slab.c:3757
tipc_exit_net+0x29/0x50 net/tipc/core.c:113
ops_exit_list net/core/net_namespace.c:186 [inline]
cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Fix it by calling flush_scheduled_work() to make sure the
tipc_net_finalize_work() stopped before releasing bcbase object.
Reported-by: syz...@sy...
Reported-by: syz...@sy...
Acked-by: Jon Maloy <jm...@re...>
Signed-off-by: Hoang Huu Le <hoa...@de...>
---
net/tipc/core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/tipc/core.c b/net/tipc/core.c
index 4f6dc74adf45..37d8695548cf 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -109,6 +109,11 @@ static void __net_exit tipc_exit_net(struct net *net)
{
tipc_detach_loopback(net);
tipc_net_stop(net);
+
+ /* Make sure the tipc_net_finalize_work stopped
+ * before releasing the resources.
+ */
+ flush_scheduled_work();
tipc_bcast_stop(net);
tipc_nametbl_stop(net);
tipc_sk_rht_destroy(net);
--
2.25.1
|
|
From: Hoang H. Le <hoa...@de...> - 2020-09-01 01:02:47
|
Thanks for pointing that out. I will revert the patch and submit another solution.
-----Original Message-----
From: Eric Dumazet <eri...@gm...>
Sent: Tuesday, September 1, 2020 12:08 AM
To: Hoang Huu Le <hoa...@de...>; jm...@re...; ma...@do...; ne...@vg...; tip...@li...
Cc: syz...@sy...; syz...@sy...
Subject: Re: [net-next] tipc: fix use-after-free in tipc_bcast_get_mode
On 8/26/20 7:56 PM, Hoang Huu Le wrote:
> Syzbot has reported those issues as:
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
> Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
>
> CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
>
> Thread 1's call trace:
> [...]
> kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
> tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
> tipc_exit_net+0x24/0x270 net/tipc/core.c:112
> [...]
>
> Thread 2's call trace:
> [...]
> tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
> has already been freed by Thread 1
>
> tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
> tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
> tipc_net_finalize net/tipc/net.c:141 [inline]
> tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
> tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
> [...]
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
> CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x1f0/0x31e lib/dump_stack.c:118
> print_address_description+0x66/0x5a0 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report+0x132/0x1d0 mm/kasan/report.c:530
> tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
> tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> [...]
> Freed by task 14058:
> save_stack mm/kasan/common.c:48 [inline]
> set_track mm/kasan/common.c:56 [inline]
> kasan_set_free_info mm/kasan/common.c:316 [inline]
> __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
> __cache_free mm/slab.c:3426 [inline]
> kfree+0x10a/0x220 mm/slab.c:3757
> tipc_exit_net+0x29/0x50 net/tipc/core.c:113
> ops_exit_list net/core/net_namespace.c:186 [inline]
> cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
>
> Fix it by calling flush_scheduled_work() to make sure the
> tipc_net_finalize_work() stopped before releasing bcbase object.
>
> Reported-by: syz...@sy...
> Reported-by: syz...@sy...
> Acked-by: Jon Maloy <jm...@re...>
> Signed-off-by: Hoang Huu Le <hoa...@de...>
> ---
> net/tipc/core.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/net/tipc/core.c b/net/tipc/core.c
> index 4f6dc74adf45..37d8695548cf 100644
> --- a/net/tipc/core.c
> +++ b/net/tipc/core.c
> @@ -109,6 +109,11 @@ static void __net_exit tipc_exit_net(struct net *net)
> {
> tipc_detach_loopback(net);
> tipc_net_stop(net);
> +
> + /* Make sure the tipc_net_finalize_work stopped
> + * before releasing the resources.
> + */
> + flush_scheduled_work();
> tipc_bcast_stop(net);
> tipc_nametbl_stop(net);
> tipc_sk_rht_destroy(net);
>
Lockdep disagrees with this change.
======================================================
WARNING: possible circular locking dependency detected
5.9.0-rc2-next-20200828-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:5/197 is trying to acquire lock:
ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: flush_workqueue+0xe1/0x13e0 kernel/workqueue.c:2777
but task is already holding lock:
ffffffff8a879430 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:565
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (pernet_ops_rwsem){++++}-{3:3}:
down_write+0x8d/0x150 kernel/locking/rwsem.c:1531
unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1861
bcm_release+0x94/0x750 net/can/bcm.c:1474
__sock_release+0xcd/0x280 net/socket.c:596
sock_close+0x18/0x20 net/socket.c:1277
__fput+0x285/0x920 fs/file_table.c:281
task_work_run+0xdd/0x190 kernel/task_work.c:141
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:140 [inline]
exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:167
syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:242
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #2 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}:
down_write+0x8d/0x150 kernel/locking/rwsem.c:1531
inode_lock include/linux/fs.h:779 [inline]
__sock_release+0x86/0x280 net/socket.c:595
sock_close+0x18/0x20 net/socket.c:1277
__fput+0x285/0x920 fs/file_table.c:281
delayed_fput+0x56/0x70 fs/file_table.c:309
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
-> #1 ((delayed_fput_work).work){+.+.}-{0:0}:
process_one_work+0x8bb/0x1670 kernel/workqueue.c:2245
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
-> #0 ((wq_completion)events){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:2496 [inline]
check_prevs_add kernel/locking/lockdep.c:2601 [inline]
validate_chain kernel/locking/lockdep.c:3218 [inline]
__lock_acquire+0x2a6b/0x5640 kernel/locking/lockdep.c:4426
lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005
flush_workqueue+0x110/0x13e0 kernel/workqueue.c:2780
flush_scheduled_work include/linux/workqueue.h:597 [inline]
tipc_exit_net+0x47/0x2a0 net/tipc/core.c:116
ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186
cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:603
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
other info that might help us debug this:
Chain exists of:
(wq_completion)events --> &sb->s_type->i_mutex_key#13 --> pernet_ops_rwsem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(pernet_ops_rwsem);
lock(&sb->s_type->i_mutex_key#13);
lock(pernet_ops_rwsem);
lock((wq_completion)events);
*** DEADLOCK ***
3 locks held by kworker/u4:5/197:
#0: ffff8880a97b1138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880a97b1138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff8880a97b1138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff8880a97b1138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff8880a97b1138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff8880a97b1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
#1: ffffc90001107da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
#2: ffffffff8a879430 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:565
stack backtrace:
CPU: 0 PID: 197 Comm: kworker/u4:5 Not tainted 5.9.0-rc2-next-20200828-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x18f/0x20d lib/dump_stack.c:118
check_noncircular+0x324/0x3e0 kernel/locking/lockdep.c:1827
check_prev_add kernel/locking/lockdep.c:2496 [inline]
check_prevs_add kernel/locking/lockdep.c:2601 [inline]
validate_chain kernel/locking/lockdep.c:3218 [inline]
__lock_acquire+0x2a6b/0x5640 kernel/locking/lockdep.c:4426
lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005
flush_workqueue+0x110/0x13e0 kernel/workqueue.c:2780
flush_scheduled_work include/linux/workqueue.h:597 [inline]
tipc_exit_net+0x47/0x2a0 net/tipc/core.c:116
ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186
cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:603
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
|
|
From: Jon M. <jm...@re...> - 2020-09-01 13:53:40
|
On 8/25/20 11:52 PM, Hoang Huu Le wrote:
> Syzbot has reported those issues as:
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
> Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
>
> CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
>
> Thread 1's call trace:
> [...]
> kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
> tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
> tipc_exit_net+0x24/0x270 net/tipc/core.c:112
> [...]
>
> Thread 2's call trace:
> [...]
> tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
> has already been freed by Thread 1
>
> tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
> tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
> tipc_net_finalize net/tipc/net.c:141 [inline]
> tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
> tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
> [...]
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
> CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x1f0/0x31e lib/dump_stack.c:118
> print_address_description+0x66/0x5a0 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report+0x132/0x1d0 mm/kasan/report.c:530
> tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
> tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> [...]
> Freed by task 14058:
> save_stack mm/kasan/common.c:48 [inline]
> set_track mm/kasan/common.c:56 [inline]
> kasan_set_free_info mm/kasan/common.c:316 [inline]
> __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
> __cache_free mm/slab.c:3426 [inline]
> kfree+0x10a/0x220 mm/slab.c:3757
> tipc_exit_net+0x29/0x50 net/tipc/core.c:113
> ops_exit_list net/core/net_namespace.c:186 [inline]
> cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
>
> Solution 1 (preferer):
> Fix it by calling flush_scheduled_work() to make sure the
> tipc_net_finalize_work() stopped before releasing bcbase object.
>
> Solution 2:
> Fix it by introducing a bit flag and returning if flag is zero
> (object had already been freed)
>
> Reported-by: syz...@sy...
> Reported-by: syz...@sy...
> Signed-off-by: Hoang Huu Le <hoa...@de...>
> ---
> net/tipc/bcast.c | 1 +
> net/tipc/core.c | 1 +
> net/tipc/core.h | 1 +
> net/tipc/net.c | 3 +++
> 4 files changed, 6 insertions(+)
>
> diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
> index 940d176e0e87..56b624c8b6d4 100644
> --- a/net/tipc/bcast.c
> +++ b/net/tipc/bcast.c
> @@ -718,6 +718,7 @@ void tipc_bcast_stop(struct net *net)
> struct tipc_net *tn = net_generic(net, tipc_net_id);
>
> synchronize_net();
> + clear_bit_unlock(0, &tn->net_exit_flag);
> kfree(tn->bcbase);
> kfree(tn->bcl);
> }
> diff --git a/net/tipc/core.c b/net/tipc/core.c
> index 4f6dc74adf45..93ea7dc05bf2 100644
> --- a/net/tipc/core.c
> +++ b/net/tipc/core.c
> @@ -60,6 +60,7 @@ static int __net_init tipc_init_net(struct net *net)
> tn->trial_addr = 0;
> tn->addr_trial_end = 0;
> tn->capabilities = TIPC_NODE_CAPABILITIES;
> + test_and_set_bit_lock(0, &tn->net_exit_flag);
> memset(tn->node_id, 0, sizeof(tn->node_id));
> memset(tn->node_id_string, 0, sizeof(tn->node_id_string));
> tn->mon_threshold = TIPC_DEF_MON_THRESHOLD;
> diff --git a/net/tipc/core.h b/net/tipc/core.h
> index 631d83c9705f..aa75882dd932 100644
> --- a/net/tipc/core.h
> +++ b/net/tipc/core.h
> @@ -143,6 +143,7 @@ struct tipc_net {
> /* TX crypto handler */
> struct tipc_crypto *crypto_tx;
> #endif
> + unsigned long net_exit_flag;
> };
>
> static inline struct tipc_net *tipc_net(struct net *net)
> diff --git a/net/tipc/net.c b/net/tipc/net.c
> index 85400e4242de..0dcbfcff5ad3 100644
> --- a/net/tipc/net.c
> +++ b/net/tipc/net.c
> @@ -132,6 +132,9 @@ static void tipc_net_finalize(struct net *net, u32 addr)
> {
> struct tipc_net *tn = tipc_net(net);
>
> + if (unlikely(!test_bit(0, &tn->net_exit_flag)))
> + return;
> +
> if (cmpxchg(&tn->node_addr, 0, addr))
> return;
> tipc_set_node_addr(net, addr);
This solution should not cause any deadlocks, I hope.
Acked-by: Jon Maloy <jm...@re...>
|
|
From: Hoang H. Le <hoa...@de...> - 2020-09-03 02:44:42
|
Hi Jon,
Below solution does not fully resolve the issue. I'm finding out another solution.
Regards,
Hoang
-----Original Message-----
From: Jon Maloy <jm...@re...>
Sent: Tuesday, September 1, 2020 8:53 PM
To: Hoang Huu Le <hoa...@de...>; ma...@do...; yin...@wi...; tip...@li...
Cc: syz...@sy...; syz...@sy...
Subject: Re: [PATCH] tipc: fix use-after-free in tipc_bcast_get_mode
On 8/25/20 11:52 PM, Hoang Huu Le wrote:
> Syzbot has reported those issues as:
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
> Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
>
> CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
>
> Thread 1's call trace:
> [...]
> kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
> tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
> tipc_exit_net+0x24/0x270 net/tipc/core.c:112
> [...]
>
> Thread 2's call trace:
> [...]
> tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
> has already been freed by Thread 1
>
> tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
> tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
> tipc_net_finalize net/tipc/net.c:141 [inline]
> tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
> tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
> [...]
>
> ==================================================================
> BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
> CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events tipc_net_finalize_work
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x1f0/0x31e lib/dump_stack.c:118
> print_address_description+0x66/0x5a0 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report+0x132/0x1d0 mm/kasan/report.c:530
> tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
> tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
> tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> [...]
> Freed by task 14058:
> save_stack mm/kasan/common.c:48 [inline]
> set_track mm/kasan/common.c:56 [inline]
> kasan_set_free_info mm/kasan/common.c:316 [inline]
> __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
> __cache_free mm/slab.c:3426 [inline]
> kfree+0x10a/0x220 mm/slab.c:3757
> tipc_exit_net+0x29/0x50 net/tipc/core.c:113
> ops_exit_list net/core/net_namespace.c:186 [inline]
> cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
> process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
> worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
> kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
>
> Solution 1 (preferer):
> Fix it by calling flush_scheduled_work() to make sure the
> tipc_net_finalize_work() stopped before releasing bcbase object.
>
> Solution 2:
> Fix it by introducing a bit flag and returning if flag is zero
> (object had already been freed)
>
> Reported-by: syz...@sy...
> Reported-by: syz...@sy...
> Signed-off-by: Hoang Huu Le <hoa...@de...>
> ---
> net/tipc/bcast.c | 1 +
> net/tipc/core.c | 1 +
> net/tipc/core.h | 1 +
> net/tipc/net.c | 3 +++
> 4 files changed, 6 insertions(+)
>
> diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
> index 940d176e0e87..56b624c8b6d4 100644
> --- a/net/tipc/bcast.c
> +++ b/net/tipc/bcast.c
> @@ -718,6 +718,7 @@ void tipc_bcast_stop(struct net *net)
> struct tipc_net *tn = net_generic(net, tipc_net_id);
>
> synchronize_net();
> + clear_bit_unlock(0, &tn->net_exit_flag);
> kfree(tn->bcbase);
> kfree(tn->bcl);
> }
> diff --git a/net/tipc/core.c b/net/tipc/core.c
> index 4f6dc74adf45..93ea7dc05bf2 100644
> --- a/net/tipc/core.c
> +++ b/net/tipc/core.c
> @@ -60,6 +60,7 @@ static int __net_init tipc_init_net(struct net *net)
> tn->trial_addr = 0;
> tn->addr_trial_end = 0;
> tn->capabilities = TIPC_NODE_CAPABILITIES;
> + test_and_set_bit_lock(0, &tn->net_exit_flag);
> memset(tn->node_id, 0, sizeof(tn->node_id));
> memset(tn->node_id_string, 0, sizeof(tn->node_id_string));
> tn->mon_threshold = TIPC_DEF_MON_THRESHOLD;
> diff --git a/net/tipc/core.h b/net/tipc/core.h
> index 631d83c9705f..aa75882dd932 100644
> --- a/net/tipc/core.h
> +++ b/net/tipc/core.h
> @@ -143,6 +143,7 @@ struct tipc_net {
> /* TX crypto handler */
> struct tipc_crypto *crypto_tx;
> #endif
> + unsigned long net_exit_flag;
> };
>
> static inline struct tipc_net *tipc_net(struct net *net)
> diff --git a/net/tipc/net.c b/net/tipc/net.c
> index 85400e4242de..0dcbfcff5ad3 100644
> --- a/net/tipc/net.c
> +++ b/net/tipc/net.c
> @@ -132,6 +132,9 @@ static void tipc_net_finalize(struct net *net, u32 addr)
> {
> struct tipc_net *tn = tipc_net(net);
>
> + if (unlikely(!test_bit(0, &tn->net_exit_flag)))
> + return;
> +
> if (cmpxchg(&tn->node_addr, 0, addr))
> return;
> tipc_set_node_addr(net, addr);
This solution should not cause any deadlocks, I hope.
Acked-by: Jon Maloy <jm...@re...>
|
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