* Re: [Cake] [PATCH net, v2 1/3] net: sched: cake: fix null pointer access issue when cake_init() fails
[not found] ` <20221018063201.306474-2-shaozhengchao@huawei.com>
@ 2022-10-18 10:44 ` Toke Høiland-Jørgensen
0 siblings, 0 replies; only message in thread
From: Toke Høiland-Jørgensen @ 2022-10-18 10:44 UTC (permalink / raw)
To: Zhengchao Shao, cake, netdev, jhs, xiyou.wangcong, jiri, davem,
edumazet, kuba, pabeni
Cc: dave.taht, weiyongjun1, yuehaibing, shaozhengchao
Zhengchao Shao <shaozhengchao@huawei.com> writes:
> When the default qdisc is cake, if the qdisc of dev_queue fails to be
> inited during mqprio_init(), cake_reset() is invoked to clear
> resources. In this case, the tins is NULL, and it will cause gpf issue.
>
> The process is as follows:
> qdisc_create_dflt()
> cake_init()
> q->tins = kvcalloc(...) --->failed, q->tins is NULL
> ...
> qdisc_put()
> ...
> cake_reset()
> ...
> cake_dequeue_one()
> b = &q->tins[...] --->q->tins is NULL
>
> The following is the Call Trace information:
> general protection fault, probably for non-canonical address
> 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> RIP: 0010:cake_dequeue_one+0xc9/0x3c0
> Call Trace:
> <TASK>
> cake_reset+0xb1/0x140
> qdisc_reset+0xed/0x6f0
> qdisc_destroy+0x82/0x4c0
> qdisc_put+0x9e/0xb0
> qdisc_create_dflt+0x2c3/0x4a0
> mqprio_init+0xa71/0x1760
> qdisc_create+0x3eb/0x1000
> tc_modify_qdisc+0x408/0x1720
> rtnetlink_rcv_msg+0x38e/0xac0
> netlink_rcv_skb+0x12d/0x3a0
> netlink_unicast+0x4a2/0x740
> netlink_sendmsg+0x826/0xcc0
> sock_sendmsg+0xc5/0x100
> ____sys_sendmsg+0x583/0x690
> ___sys_sendmsg+0xe8/0x160
> __sys_sendmsg+0xbf/0x160
> do_syscall_64+0x35/0x80
> entry_SYSCALL_64_after_hwframe+0x46/0xb0
> RIP: 0033:0x7f89e5122d04
> </TASK>
>
> Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
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