Message ID | 20230726011432.19250-1-kuniyu@amazon.com (mailing list archive) |
---|---|
State | Superseded |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | [v1,net] net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX. | expand |
On Tue, Jul 25, 2023 at 06:14:32PM -0700, Kuniyuki Iwashima wrote: > syzkaller found a zero division error [0] in div_s64_rem() called from > get_cycle_time_elapsed(), where sched->cycle_time is the divisor. > > We have tests in parse_taprio_schedule() so that cycle_time will never > be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed(). > > The problem is that the types of divisor are different; cycle_time is > s64, but the argument of div_s64_rem() is s32. > > syzkaller fed this input and 0x100000000 is cast to s32 to be 0. > > @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000} > > We use s64 for cycle_time to cast it to ktime_t, so let's keep it and > set min/max for cycle_time. > > [0]: > divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI > CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > Workqueue: ipv6_addrconf addrconf_dad_work > RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline] > RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline] > RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344 > Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10 > RSP: 0018:ffffc90000acf260 EFLAGS: 00010206 > RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000 > RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934 > R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800 > R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0 > PKRU: 55555554 > Call Trace: > <TASK> > get_packet_txtime net/sched/sch_taprio.c:508 [inline] > taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577 > taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658 > dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732 > __dev_xmit_skb net/core/dev.c:3821 [inline] > __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169 > dev_queue_xmit include/linux/netdevice.h:3088 [inline] > neigh_resolve_output net/core/neighbour.c:1552 [inline] > neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532 > neigh_output include/net/neighbour.h:544 [inline] > ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135 > __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196 > ip6_finish_output net/ipv6/ip6_output.c:207 [inline] > NF_HOOK_COND include/linux/netfilter.h:292 [inline] > ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228 > dst_output include/net/dst.h:458 [inline] > NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303 > ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508 > ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666 > addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175 > process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597 > worker_thread+0x60f/0x1240 kernel/workqueue.c:2748 > kthread+0x2fe/0x3f0 kernel/kthread.c:389 > ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 > </TASK> > Modules linked in: > > Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode") > Reported-by: syzkaller <syzkaller@googlegroups.com> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <simon.horman@corigine.com>
On Wed, Jul 26, 2023 at 3:15 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > syzkaller found a zero division error [0] in div_s64_rem() called from > get_cycle_time_elapsed(), where sched->cycle_time is the divisor. > > We have tests in parse_taprio_schedule() so that cycle_time will never > be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed(). > > The problem is that the types of divisor are different; cycle_time is > s64, but the argument of div_s64_rem() is s32. > > syzkaller fed this input and 0x100000000 is cast to s32 to be 0. > > @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000} > > We use s64 for cycle_time to cast it to ktime_t, so let's keep it and > set min/max for cycle_time. > > [0]: > divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI > CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > Workqueue: ipv6_addrconf addrconf_dad_work > RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline] > RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline] > RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344 > Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10 > RSP: 0018:ffffc90000acf260 EFLAGS: 00010206 > RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000 > RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934 > R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800 > R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0 > PKRU: 55555554 > Call Trace: > <TASK> > get_packet_txtime net/sched/sch_taprio.c:508 [inline] > taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577 > taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658 > dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732 > __dev_xmit_skb net/core/dev.c:3821 [inline] > __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169 > dev_queue_xmit include/linux/netdevice.h:3088 [inline] > neigh_resolve_output net/core/neighbour.c:1552 [inline] > neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532 > neigh_output include/net/neighbour.h:544 [inline] > ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135 > __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196 > ip6_finish_output net/ipv6/ip6_output.c:207 [inline] > NF_HOOK_COND include/linux/netfilter.h:292 [inline] > ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228 > dst_output include/net/dst.h:458 [inline] > NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303 > ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508 > ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666 > addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175 > process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597 > worker_thread+0x60f/0x1240 kernel/workqueue.c:2748 > kthread+0x2fe/0x3f0 kernel/kthread.c:389 > ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 > </TASK> > Modules linked in: > > Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode") > Reported-by: syzkaller <syzkaller@googlegroups.com> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> > --- > net/sched/sch_taprio.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c > index 717ae51d94a0..72808acb5435 100644 > --- a/net/sched/sch_taprio.c > +++ b/net/sched/sch_taprio.c > @@ -1015,6 +1015,11 @@ static const struct nla_policy taprio_tc_policy[TCA_TAPRIO_TC_ENTRY_MAX + 1] = { > TC_FP_PREEMPTIBLE), > }; > > +static struct netlink_range_validation_signed taprio_cycle_time_range = { > + .min = 1, > + .max = INT_MAX, > +}; > + > static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { > [TCA_TAPRIO_ATTR_PRIOMAP] = { > .len = sizeof(struct tc_mqprio_qopt) > @@ -1023,7 +1028,8 @@ static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { > [TCA_TAPRIO_ATTR_SCHED_BASE_TIME] = { .type = NLA_S64 }, > [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY] = { .type = NLA_NESTED }, > [TCA_TAPRIO_ATTR_SCHED_CLOCKID] = { .type = NLA_S32 }, > - [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = { .type = NLA_S64 }, > + [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = > + NLA_POLICY_FULL_RANGE_SIGNED(NLA_S64, &taprio_cycle_time_range), > [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 }, > [TCA_TAPRIO_ATTR_FLAGS] = { .type = NLA_U32 }, > [TCA_TAPRIO_ATTR_TXTIME_DELAY] = { .type = NLA_U32 }, > -- > 2.30.2 > Not sure this is enough (syzbot could very well find other ways to trigger bugs caused by overflows) What about setup_txtime() ? It seems possible to have overflows there... What about adding to your patch the following ? diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 717ae51d94a0ae4f45317e8ba86f51ab4ac41aa6..a4bdc5d8bd6fc546bc835c953db81cdaf7285a40 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1158,7 +1158,10 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb, NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0"); return -EINVAL; } - + if (cycle > INT_MAX) { + NL_SET_ERR_MSG(extack, "'cycle_time' is too big"); + return -EINVAL; + } new->cycle_time = cycle; } @@ -1347,7 +1350,7 @@ static void setup_txtime(struct taprio_sched *q, struct sched_gate_list *sched, ktime_t base) { struct sched_entry *entry; - u32 interval = 0; + u64 interval = 0; list_for_each_entry(entry, &sched->entries, list) { entry->next_txtime = ktime_add_ns(base, interval);
From: Eric Dumazet <edumazet@google.com> Date: Wed, 26 Jul 2023 15:54:12 +0200 > On Wed, Jul 26, 2023 at 3:15 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > > > syzkaller found a zero division error [0] in div_s64_rem() called from > > get_cycle_time_elapsed(), where sched->cycle_time is the divisor. > > > > We have tests in parse_taprio_schedule() so that cycle_time will never > > be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed(). > > > > The problem is that the types of divisor are different; cycle_time is > > s64, but the argument of div_s64_rem() is s32. > > > > syzkaller fed this input and 0x100000000 is cast to s32 to be 0. > > > > @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000} > > > > We use s64 for cycle_time to cast it to ktime_t, so let's keep it and > > set min/max for cycle_time. > > > > [0]: > > divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI > > CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > > Workqueue: ipv6_addrconf addrconf_dad_work > > RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline] > > RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline] > > RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344 > > Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10 > > RSP: 0018:ffffc90000acf260 EFLAGS: 00010206 > > RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf > > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000 > > RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934 > > R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800 > > R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000 > > FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0 > > PKRU: 55555554 > > Call Trace: > > <TASK> > > get_packet_txtime net/sched/sch_taprio.c:508 [inline] > > taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577 > > taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658 > > dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732 > > __dev_xmit_skb net/core/dev.c:3821 [inline] > > __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169 > > dev_queue_xmit include/linux/netdevice.h:3088 [inline] > > neigh_resolve_output net/core/neighbour.c:1552 [inline] > > neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532 > > neigh_output include/net/neighbour.h:544 [inline] > > ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135 > > __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196 > > ip6_finish_output net/ipv6/ip6_output.c:207 [inline] > > NF_HOOK_COND include/linux/netfilter.h:292 [inline] > > ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228 > > dst_output include/net/dst.h:458 [inline] > > NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303 > > ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508 > > ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666 > > addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175 > > process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597 > > worker_thread+0x60f/0x1240 kernel/workqueue.c:2748 > > kthread+0x2fe/0x3f0 kernel/kthread.c:389 > > ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 > > </TASK> > > Modules linked in: > > > > Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode") > > Reported-by: syzkaller <syzkaller@googlegroups.com> > > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> > > --- > > net/sched/sch_taprio.c | 8 +++++++- > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c > > index 717ae51d94a0..72808acb5435 100644 > > --- a/net/sched/sch_taprio.c > > +++ b/net/sched/sch_taprio.c > > @@ -1015,6 +1015,11 @@ static const struct nla_policy taprio_tc_policy[TCA_TAPRIO_TC_ENTRY_MAX + 1] = { > > TC_FP_PREEMPTIBLE), > > }; > > > > +static struct netlink_range_validation_signed taprio_cycle_time_range = { > > + .min = 1, > > + .max = INT_MAX, > > +}; > > + > > static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { > > [TCA_TAPRIO_ATTR_PRIOMAP] = { > > .len = sizeof(struct tc_mqprio_qopt) > > @@ -1023,7 +1028,8 @@ static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { > > [TCA_TAPRIO_ATTR_SCHED_BASE_TIME] = { .type = NLA_S64 }, > > [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY] = { .type = NLA_NESTED }, > > [TCA_TAPRIO_ATTR_SCHED_CLOCKID] = { .type = NLA_S32 }, > > - [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = { .type = NLA_S64 }, > > + [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = > > + NLA_POLICY_FULL_RANGE_SIGNED(NLA_S64, &taprio_cycle_time_range), > > [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 }, > > [TCA_TAPRIO_ATTR_FLAGS] = { .type = NLA_U32 }, > > [TCA_TAPRIO_ATTR_TXTIME_DELAY] = { .type = NLA_U32 }, > > -- > > 2.30.2 > > > > Not sure this is enough (syzbot could very well find other ways to > trigger bugs caused by overflows) > > What about setup_txtime() ? It seems possible to have overflows there... > > What about adding to your patch the following ? Ah good catch! I'll post v2 with Co-developed-by :) Thanks! > > diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c > index 717ae51d94a0ae4f45317e8ba86f51ab4ac41aa6..a4bdc5d8bd6fc546bc835c953db81cdaf7285a40 > 100644 > --- a/net/sched/sch_taprio.c > +++ b/net/sched/sch_taprio.c > @@ -1158,7 +1158,10 @@ static int parse_taprio_schedule(struct > taprio_sched *q, struct nlattr **tb, > NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0"); > return -EINVAL; > } > - > + if (cycle > INT_MAX) { > + NL_SET_ERR_MSG(extack, "'cycle_time' is too big"); > + return -EINVAL; > + } > new->cycle_time = cycle; > } > > @@ -1347,7 +1350,7 @@ static void setup_txtime(struct taprio_sched *q, > struct sched_gate_list *sched, ktime_t base) > { > struct sched_entry *entry; > - u32 interval = 0; > + u64 interval = 0; > > list_for_each_entry(entry, &sched->entries, list) { > entry->next_txtime = ktime_add_ns(base, interval); >
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 717ae51d94a0..72808acb5435 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1015,6 +1015,11 @@ static const struct nla_policy taprio_tc_policy[TCA_TAPRIO_TC_ENTRY_MAX + 1] = { TC_FP_PREEMPTIBLE), }; +static struct netlink_range_validation_signed taprio_cycle_time_range = { + .min = 1, + .max = INT_MAX, +}; + static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { [TCA_TAPRIO_ATTR_PRIOMAP] = { .len = sizeof(struct tc_mqprio_qopt) @@ -1023,7 +1028,8 @@ static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { [TCA_TAPRIO_ATTR_SCHED_BASE_TIME] = { .type = NLA_S64 }, [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY] = { .type = NLA_NESTED }, [TCA_TAPRIO_ATTR_SCHED_CLOCKID] = { .type = NLA_S32 }, - [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = { .type = NLA_S64 }, + [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = + NLA_POLICY_FULL_RANGE_SIGNED(NLA_S64, &taprio_cycle_time_range), [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 }, [TCA_TAPRIO_ATTR_FLAGS] = { .type = NLA_U32 }, [TCA_TAPRIO_ATTR_TXTIME_DELAY] = { .type = NLA_U32 },
syzkaller found a zero division error [0] in div_s64_rem() called from get_cycle_time_elapsed(), where sched->cycle_time is the divisor. We have tests in parse_taprio_schedule() so that cycle_time will never be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed(). The problem is that the types of divisor are different; cycle_time is s64, but the argument of div_s64_rem() is s32. syzkaller fed this input and 0x100000000 is cast to s32 to be 0. @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000} We use s64 for cycle_time to cast it to ktime_t, so let's keep it and set min/max for cycle_time. [0]: divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline] RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline] RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344 Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10 RSP: 0018:ffffc90000acf260 EFLAGS: 00010206 RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000 RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934 R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800 R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0 PKRU: 55555554 Call Trace: <TASK> get_packet_txtime net/sched/sch_taprio.c:508 [inline] taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577 taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658 dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732 __dev_xmit_skb net/core/dev.c:3821 [inline] __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169 dev_queue_xmit include/linux/netdevice.h:3088 [inline] neigh_resolve_output net/core/neighbour.c:1552 [inline] neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532 neigh_output include/net/neighbour.h:544 [inline] ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135 __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196 ip6_finish_output net/ipv6/ip6_output.c:207 [inline] NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228 dst_output include/net/dst.h:458 [inline] NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303 ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508 ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666 addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175 process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597 worker_thread+0x60f/0x1240 kernel/workqueue.c:2748 kthread+0x2fe/0x3f0 kernel/kthread.c:389 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 </TASK> Modules linked in: Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> --- net/sched/sch_taprio.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)