Description
In the Linux kernel, the following vulnerability has been resolved:
net: mdio: fix undefined behavior in bit shift for __mdiobus_register
Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:
UBSAN: shift-out-of-bounds in drivers/net/phy/mdio_bus.c:586:27
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
<TASK>
dump_stack_lvl+0x7d/0xa5
dump_stack+0x15/0x1b
ubsan_epilogue+0xe/0x4e
__ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
__mdiobus_register+0x49d/0x4e0
fixed_mdio_bus_init+0xd8/0x12d
do_one_initcall+0x76/0x430
kernel_init_freeable+0x3b3/0x422
kernel_init+0x24/0x1e0
ret_from_fork+0x1f/0x30
</TASK>
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 2.6.28 | 4.9.333 |
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 | 6.0.8-1 | — |
| Debian 13 | linux | 6.0.8-1 | — |
| Debian 12 | linux | 6.0.8-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1014.16 | — |
| Ubuntu 24.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-60.66 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1030.34 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1033.40 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1033.40.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1029.36 | — |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1027.32 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1015.19 | — |
| Ubuntu 22.04 LTS | linux-ibm | 5.15.0-1025.28 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1025.30 | — |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1028.33 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1017.17 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1029.35 | — |
| Ubuntu 22.04 LTS | linux-raspi | 5.15.0-1024.26 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-139.156 | — |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1096.104 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1030.34~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1103.109 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1033.40~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1058.64 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1100.109 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1029.36~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-60.66~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1044.49 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1025.30~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-iot | 5.4.0-1012.14 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1086.92 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1093.102 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1029.35~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1080.91 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1029.33~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-xilinx-zynqmp | 5.4.0-1021.25 | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-206.217 | — |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1151.164 | — |
| Ubuntu 18.04 LTS | linux-aws-5.4 | 5.4.0-1096.104~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-azure-4.15 | 4.15.0-1162.177 | — |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1103.109~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-4.15 | 4.15.0-1146.162 | — |
| Ubuntu 18.04 LTS | linux-gcp-5.4 | 5.4.0-1100.109~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-139.156~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-ibm-5.4 | 5.4.0-1044.49~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1136.141 | — |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1115.126 | — |
| Ubuntu 18.04 LTS | linux-oracle-5.4 | 5.4.0-1093.102~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1080.91~18.04.1 | — |
Show 9 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 FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1096.104+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1103.109+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1072.81 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1100.109+fips1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-aws-fips | 4.15.0-2090.96 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-azure-fips | 4.15.0-2071.77 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips | 4.15.0-1108.119 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-gcp-fips | 4.15.0-2055.60 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +2 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux-aws-hwe | 4.15.0-1151.164~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-azure | 4.15.0-1162.177~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-gcp | 4.15.0-1146.162~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-hwe | 4.15.0-206.217~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-oracle | 4.15.0-1115.126~16.04.1 | — |
| Ubuntu Pro 14.04 LTS | linux +2 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1162.177~14.04.1 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.261.1 | SUSE-SU-2025:01983-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.261.1 | SUSE-SU-2025:01983-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_69 | 1-8.3.1 | SUSE-SU-2025:01983-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | kernel-livepatch-4.14.299-223.520 | 1.0-0.amzn2 | ALAS2-2022-1888 |
| Amazon Linux 2 | perf +8 | 4.14.299-223.520.amzn2 | ALAS2-2022-1888 |
Advisories 2
- SUSE-SU-2025:01983-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2-2022-1888 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Dec 19, 2025
References
- https://git.kernel.org/stable/c/20ed01a7b9af6e6a3c33761eebbb710ea6dd49b7
- https://git.kernel.org/stable/c/7006176a3c863e3e353ce1b8a349ef5bb1b9320e
- https://git.kernel.org/stable/c/a3fafc974be37319679f36dc4e7cca7db1e02973
- https://git.kernel.org/stable/c/4954b5359eb141499492fadfab891e28905509e2
- https://git.kernel.org/stable/c/634f066d02bdb22a26da7deb0c7617ab1a65fc9d
- https://git.kernel.org/stable/c/985a88bf0b27193522bba7856b1763f428cef19d
- https://git.kernel.org/stable/c/6ce6f8f8f6316da6f92afe7490bc2f0b654d68e0
- https://git.kernel.org/stable/c/40e4eb324c59e11fcb927aa46742d28aba6ecb8a