* [PATCH net] sch_cake: do not call cake_destroy() from cake_init()
@ 2021-12-10 8:15 Eric Dumazet
2021-12-10 11:02 ` Toke Høiland-Jørgensen
0 siblings, 1 reply; 4+ messages in thread
From: Eric Dumazet @ 2021-12-10 8:15 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski
Cc: netdev, Eric Dumazet, Eric Dumazet, syzbot,
Toke Høiland-Jørgensen
From: Eric Dumazet <edumazet@google.com>
qdiscs are not supposed to call their own destroy() method
from init(), because core stack already does that.
syzbot was able to trigger use after free:
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock_common kernel/locking/mutex.c:586 [inline]
WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740
Modules linked in:
CPU: 0 PID: 21902 Comm: syz-executor189 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:586 [inline]
RIP: 0010:__mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740
Code: 08 84 d2 0f 85 19 08 00 00 8b 05 97 38 4b 04 85 c0 0f 85 27 f7 ff ff 48 c7 c6 20 00 ac 89 48 c7 c7 a0 fe ab 89 e8 bf 76 ba ff <0f> 0b e9 0d f7 ff ff 48 8b 44 24 40 48 8d b8 c8 08 00 00 48 89 f8
RSP: 0018:ffffc9000627f290 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802315d700 RSI: ffffffff815f1db8 RDI: fffff52000c4fe44
RBP: ffff88818f28e000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815ebb5e R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc9000627f458 R15: 0000000093c30000
FS: 0000555556abc400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda689c3303 CR3: 000000001cfbb000 CR4: 0000000000350ef0
Call Trace:
<TASK>
tcf_chain0_head_change_cb_del+0x2e/0x3d0 net/sched/cls_api.c:810
tcf_block_put_ext net/sched/cls_api.c:1381 [inline]
tcf_block_put_ext net/sched/cls_api.c:1376 [inline]
tcf_block_put+0xbc/0x130 net/sched/cls_api.c:1394
cake_destroy+0x3f/0x80 net/sched/sch_cake.c:2695
qdisc_create.constprop.0+0x9da/0x10f0 net/sched/sch_api.c:1293
tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660
rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
___sys_sendmsg+0xf3/0x170 net/socket.c:2463
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f1bb06badb9
Code: Unable to access opcode bytes at RIP 0x7f1bb06bad8f.
RSP: 002b:00007fff3012a658 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f1bb06badb9
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000246 R12: 00007fff3012a688
R13: 00007fff3012a6a0 R14: 00007fff3012a6e0 R15: 00000000000013c2
</TASK>
Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 3c2300d144681869a37ada0d20966f9b5b145653..857aaebd49f4315502928fb1f75d2c85eb63eb51 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -2736,7 +2736,7 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt,
q->tins = kvcalloc(CAKE_MAX_TINS, sizeof(struct cake_tin_data),
GFP_KERNEL);
if (!q->tins)
- goto nomem;
+ return -ENOMEM;
for (i = 0; i < CAKE_MAX_TINS; i++) {
struct cake_tin_data *b = q->tins + i;
@@ -2766,10 +2766,6 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt,
q->min_netlen = ~0;
q->min_adjlen = ~0;
return 0;
-
-nomem:
- cake_destroy(sch);
- return -ENOMEM;
}
static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
--
2.34.1.173.g76aa8bc2d0-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net] sch_cake: do not call cake_destroy() from cake_init()
2021-12-10 8:15 [PATCH net] sch_cake: do not call cake_destroy() from cake_init() Eric Dumazet
@ 2021-12-10 11:02 ` Toke Høiland-Jørgensen
2021-12-10 11:07 ` Eric Dumazet
0 siblings, 1 reply; 4+ messages in thread
From: Toke Høiland-Jørgensen @ 2021-12-10 11:02 UTC (permalink / raw)
To: Eric Dumazet, David S . Miller, Jakub Kicinski
Cc: netdev, Eric Dumazet, Eric Dumazet, syzbot
Eric Dumazet <eric.dumazet@gmail.com> writes:
> From: Eric Dumazet <edumazet@google.com>
>
> qdiscs are not supposed to call their own destroy() method
> from init(), because core stack already does that.
>
> syzbot was able to trigger use after free:
>
> DEBUG_LOCKS_WARN_ON(lock->magic != lock)
> WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock_common kernel/locking/mutex.c:586 [inline]
> WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740
> Modules linked in:
> CPU: 0 PID: 21902 Comm: syz-executor189 Not tainted 5.16.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:586 [inline]
> RIP: 0010:__mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740
> Code: 08 84 d2 0f 85 19 08 00 00 8b 05 97 38 4b 04 85 c0 0f 85 27 f7 ff ff 48 c7 c6 20 00 ac 89 48 c7 c7 a0 fe ab 89 e8 bf 76 ba ff <0f> 0b e9 0d f7 ff ff 48 8b 44 24 40 48 8d b8 c8 08 00 00 48 89 f8
> RSP: 0018:ffffc9000627f290 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff88802315d700 RSI: ffffffff815f1db8 RDI: fffff52000c4fe44
> RBP: ffff88818f28e000 R08: 0000000000000000 R09: 0000000000000000
> R10: ffffffff815ebb5e R11: 0000000000000000 R12: 0000000000000000
> R13: dffffc0000000000 R14: ffffc9000627f458 R15: 0000000093c30000
> FS: 0000555556abc400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fda689c3303 CR3: 000000001cfbb000 CR4: 0000000000350ef0
> Call Trace:
> <TASK>
> tcf_chain0_head_change_cb_del+0x2e/0x3d0 net/sched/cls_api.c:810
> tcf_block_put_ext net/sched/cls_api.c:1381 [inline]
> tcf_block_put_ext net/sched/cls_api.c:1376 [inline]
> tcf_block_put+0xbc/0x130 net/sched/cls_api.c:1394
> cake_destroy+0x3f/0x80 net/sched/sch_cake.c:2695
> qdisc_create.constprop.0+0x9da/0x10f0 net/sched/sch_api.c:1293
> tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660
> rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571
> netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
> netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
> netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
> netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921
> sock_sendmsg_nosec net/socket.c:704 [inline]
> sock_sendmsg+0xcf/0x120 net/socket.c:724
> ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
> ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
> __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x7f1bb06badb9
> Code: Unable to access opcode bytes at RIP 0x7f1bb06bad8f.
> RSP: 002b:00007fff3012a658 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f1bb06badb9
> RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000003
> RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003
> R10: 0000000000000003 R11: 0000000000000246 R12: 00007fff3012a688
> R13: 00007fff3012a6a0 R14: 00007fff3012a6e0 R15: 00000000000013c2
> </TASK>
>
> Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Oops, thanks for the fix! I'm a little puzzled with the patch has my
S-o-b, though? It should probably be replaced by:
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] sch_cake: do not call cake_destroy() from cake_init()
2021-12-10 11:02 ` Toke Høiland-Jørgensen
@ 2021-12-10 11:07 ` Eric Dumazet
2021-12-10 11:34 ` Toke Høiland-Jørgensen
0 siblings, 1 reply; 4+ messages in thread
From: Eric Dumazet @ 2021-12-10 11:07 UTC (permalink / raw)
To: Toke Høiland-Jørgensen
Cc: Eric Dumazet, David S . Miller, Jakub Kicinski, netdev, syzbot
On Fri, Dec 10, 2021 at 3:02 AM Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>
> Eric Dumazet <eric.dumazet@gmail.com> writes:
>
> > From: Eric Dumazet <edumazet@google.com>
> >
> > qdiscs are not supposed to call their own destroy() method
> > from init(), because core stack already does that.
> >
> > syzbot was able to trigger use after free:
> >
> > Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
> > Reported-by: syzbot <syzkaller@googlegroups.com>
> > Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
>
> Oops, thanks for the fix! I'm a little puzzled with the patch has my
> S-o-b, though? It should probably be replaced by:
>
> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Right, user error from my side, I copied it from your commit changelog
and forgot to s/Signed-off-by/Cc/
Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] sch_cake: do not call cake_destroy() from cake_init()
2021-12-10 11:07 ` Eric Dumazet
@ 2021-12-10 11:34 ` Toke Høiland-Jørgensen
0 siblings, 0 replies; 4+ messages in thread
From: Toke Høiland-Jørgensen @ 2021-12-10 11:34 UTC (permalink / raw)
To: Eric Dumazet
Cc: Eric Dumazet, David S . Miller, Jakub Kicinski, netdev, syzbot
Eric Dumazet <edumazet@google.com> writes:
> On Fri, Dec 10, 2021 at 3:02 AM Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>>
>> Eric Dumazet <eric.dumazet@gmail.com> writes:
>>
>> > From: Eric Dumazet <edumazet@google.com>
>> >
>> > qdiscs are not supposed to call their own destroy() method
>> > from init(), because core stack already does that.
>> >
>> > syzbot was able to trigger use after free:
>
>> >
>> > Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
>> > Signed-off-by: Eric Dumazet <edumazet@google.com>
>> > Reported-by: syzbot <syzkaller@googlegroups.com>
>> > Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
>>
>> Oops, thanks for the fix! I'm a little puzzled with the patch has my
>> S-o-b, though? It should probably be replaced by:
>>
>> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
>
> Right, user error from my side, I copied it from your commit changelog
> and forgot to s/Signed-off-by/Cc/
Ah, right, makes sense; no worries :)
-Toke
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-12-10 8:15 [PATCH net] sch_cake: do not call cake_destroy() from cake_init() Eric Dumazet
2021-12-10 11:02 ` Toke Høiland-Jørgensen
2021-12-10 11:07 ` Eric Dumazet
2021-12-10 11:34 ` Toke Høiland-Jørgensen
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