| Message ID | 20221018063201.306474-2-shaozhengchao@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 51f9a8921ceacd7bf0d3f47fa867a64988ba1dcb |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | fix null pointer access issue in qdisc | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net |
| netdev/fixes_present | success | Fixes tag present in non-next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Series has a cover letter |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/cc_maintainers | success | CCed 11 of 11 maintainers |
| netdev/build_clang | success | Errors and warnings before: 0 this patch: 0 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | Fixes tag looks correct |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 12 lines checked |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
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>
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 55c6879d2c7e..87f8ce2c65ee 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -2224,8 +2224,12 @@ static struct sk_buff *cake_dequeue(struct Qdisc *sch) static void cake_reset(struct Qdisc *sch) { + struct cake_sched_data *q = qdisc_priv(sch); u32 c; + if (!q->tins) + return; + for (c = 0; c < CAKE_MAX_TINS; c++) cake_clear_tin(sch, c); }
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> --- net/sched/sch_cake.c | 4 ++++ 1 file changed, 4 insertions(+)