Fix CVE-2024-36244.
Kuniyuki Iwashima (1): net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.
Vladimir Oltean (1): net/sched: taprio: extend minimum interval restriction to entire cycle too
net/sched/sch_taprio.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
From: Kuniyuki Iwashima kuniyu@amazon.com
mainline inclusion from mainline-v6.5-rc5 commit e739718444f7bf2fa3d70d101761ad83056ca628 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA7D5O CVE: CVE-2024-36244
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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syzkaller found 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 max for cycle_time.
While at it, we prevent overflow in setup_txtime() and add another test in parse_taprio_schedule() to check if cycle_time overflows.
Also, we add a new tdc test case for this issue.
[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 Co-developed-by: Eric Dumazet edumazet@google.com Co-developed-by: Pedro Tammela pctammela@mojatatu.com Acked-by: Vinicius Costa Gomes vinicius.gomes@intel.com Signed-off-by: David S. Miller davem@davemloft.net Conflicts: net/sched/sch_taprio.c tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json [commit 8a3b3667ddbd("selftests/tc-testing: add selftests for taprio qdisc") that add taprio.json wasnt merged. commit a54fc09e4cba wasnt merged, which add taprio_tc_policy.] Signed-off-by: Dong Chenchen dongchenchen2@huawei.com --- net/sched/sch_taprio.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 41fa731e7c47..c76aa904d878 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -769,6 +769,11 @@ static const struct nla_policy entry_policy[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = { [TCA_TAPRIO_SCHED_ENTRY_INTERVAL] = { .type = NLA_U32 }, };
+static struct netlink_range_validation_signed taprio_cycle_time_range = { + .min = 0, + .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) @@ -777,7 +782,8 @@ 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 }, @@ -912,6 +918,11 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb, return -EINVAL; }
+ if (cycle < 0 || cycle > INT_MAX) { + NL_SET_ERR_MSG(extack, "'cycle_time' is too big"); + return -EINVAL; + } + new->cycle_time = cycle; }
@@ -1113,7 +1124,7 @@ 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: Vladimir Oltean vladimir.oltean@nxp.com
mainline inclusion from mainline-v6.10-rc2 commit fb66df20a7201e60f2b13d7f95d031b31a8831d3 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA7D5O CVE: CVE-2024-36244
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
It is possible for syzbot to side-step the restriction imposed by the blamed commit in the Fixes: tag, because the taprio UAPI permits a cycle-time different from (and potentially shorter than) the sum of entry intervals.
We need one more restriction, which is that the cycle time itself must be larger than N * ETH_ZLEN bit times, where N is the number of schedule entries. This restriction needs to apply regardless of whether the cycle time came from the user or was the implicit, auto-calculated value, so we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)" branch. This way covers both conditions and scenarios.
Add a selftest which illustrates the issue triggered by syzbot.
Fixes: b5b73b26b3ca ("taprio: Fix allowing too small intervals") Reported-by: syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/ Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Conflicts: net/sched/sch_taprio.c tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json [commit a306a90c8ffe add taprio_calculate_gate_durations() to calculate tc gate durations, which wasnt merged lead to conflicts.commit 8a3b3667ddbd ("selftests/tc-testing: add selftests for taprio qdisc") that add taprio.json wasnt merged] Signed-off-by: Dong Chenchen dongchenchen2@huawei.com --- net/sched/sch_taprio.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index c76aa904d878..df2a372445a6 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -913,11 +913,6 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb, list_for_each_entry(entry, &new->entries, list) cycle = ktime_add_ns(cycle, entry->interval);
- if (!cycle) { - NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0"); - return -EINVAL; - } - if (cycle < 0 || cycle > INT_MAX) { NL_SET_ERR_MSG(extack, "'cycle_time' is too big"); return -EINVAL; @@ -926,6 +921,11 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb, new->cycle_time = cycle; }
+ if (new->cycle_time < new->num_entries * length_to_duration(q, ETH_ZLEN)) { + NL_SET_ERR_MSG(extack, "'cycle_time' is too small"); + return -EINVAL; + } + return 0; }
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