Description
In the Linux kernel, the following vulnerability has been resolved:
net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.
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:
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.3 | 5.15.126 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.4.11-1 | — |
| Debian 13 | linux | 6.4.11-1 | — |
| Debian 12 | linux | 6.1.52-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1031.33 | — |
| Ubuntu 24.04 LTS | linux-riscv +10 | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-88.98 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1049.54 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1051.59 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1051.59.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1046.54 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1046.51 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1032.38 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1042.45 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1045.51 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1040.40 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1019.19 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1006.6 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1047.53 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1025.29 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1049.54~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1051.59~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1046.54~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-88.98~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1042.45~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1045.51~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1019.19~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1047.53~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1045.49~20.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1042.44 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1050.56 | — |
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux +10 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux-aws-5.4 +6 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | bpftool | 7.3.0-427.13.1.el9_4 | RHSA-2024:2394 |
| RHEL 9 | rv +64 | 5.14.0-427.13.1.el9_4 | RHSA-2024:2394 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.2 EUS | bpftool | 7.0.0-284.88.1.el9_2 | RHSA-2024:8157 |
| RHEL 9.2 EUS | perf +48 | 5.14.0-284.88.1.el9_2 | RHSA-2024:8157 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.28.1 | SUSE-SU-2026:0315-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.24.1 | SUSE-SU-2026:0281-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.28.1.150700.17.19.1 | SUSE-SU-2026:0315-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.84.1.150600.12.38.1 | SUSE-SU-2026:0293-1 |
| SLES 15 SP5 | kernel-64kb +6 | 5.14.21-150500.55.133.1 | SUSE-SU-2026:0317-1 |
| SLES 15 SP5 | kernel-default-base | 5.14.21-150500.55.133.1.150500.6.65.1 | SUSE-SU-2026:0317-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | kernel-default-base | 6.4.0-150600.23.84.1.150600.12.38.1 | SUSE-SU-2026:0293-1 |
| SLES for SAP 15 SP6 | kernel-docs +4 | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| SLES for SAP 15 SP5 | kernel-default-base | 5.14.21-150500.55.133.1.150500.6.65.1 | SUSE-SU-2026:0317-1 |
| SLES for SAP 15 SP5 | kernel-docs +4 | 5.14.21-150500.55.133.1 | SUSE-SU-2026:0317-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20876-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20477-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20845-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20477-1 |
| SLE Micro 5.5 | kernel-default-base | 5.14.21-150500.55.133.1.150500.6.65.1 | SUSE-SU-2026:0317-1 |
| SLE Micro 5.5 | kernel-rt +1 | 5.14.21-150500.13.118.1 | SUSE-SU-2026:0263-1 |
| SLE Micro 5.5 | kernel-source +1 | 5.14.21-150500.55.133.1 | SUSE-SU-2026:0317-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.28.1 | SUSE-SU-2026:0315-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_8 | 1-150700.1.3.1 | SUSE-SU-2026:0278-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_8 | 1-150700.15.3.1 | SUSE-SU-2026:0315-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_19 | 1-150600.13.3.1 | SUSE-SU-2026:0293-1 |
| SLE Live Patching 15 SP5 | kernel-default | 5.14.21-150500.55.133.1 | SUSE-SU-2026:0317-1 |
| SLE Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_34 | 1-150500.11.3.1 | SUSE-SU-2026:0317-1 |
| SLE HPC 15 SP5 | kernel-64kb +5 | 5.14.21-150500.55.133.1 | SUSE-SU-2026:0317-1 |
| SLE HPC 15 SP5 | kernel-default-base | 5.14.21-150500.55.133.1.150500.6.65.1 | SUSE-SU-2026:0317-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.28.1 | SUSE-SU-2026:0278-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.84.1.150600.12.38.1 | SUSE-SU-2026:0293-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.49-69.116 | 1.0-0.amzn2023 | ALAS2023-2023-330 |
| Amazon Linux 2023 | perf +12 | 6.1.49-69.116.amzn2023 | ALAS2023-2023-330 |
Advisories 14
- WID-SEC-2025-2941 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 9, 2026
- RHSA-2024:2394 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2024:8157 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Aug 20, 2026
- SUSE-SU-2026:20876-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 31, 2026
- SUSE-SU-2026:20845-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 28, 2026
- SUSE-SU-2026:20498-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20477-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0317-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0293-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0281-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0278-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0315-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2023-2023-330 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026
- SUSE-SU-2026:0263-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026