Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Add preempt_count_{sub,add} into btf id deny list
The recursion check in __bpf_prog_enter* and __bpf_prog_exit*
leave preempt_count_{sub,add} unprotected. When attaching trampoline to
them we get panic as follows,
[ 867.843050] BUG: TASK stack guard page was hit at 0000000009d325cf (stack is 0000000046a46a15..00000000537e7b28)
[ 867.843064] stack guard page: 0000 [#1] PREEMPT SMP NOPTI
[ 867.843067] CPU: 8 PID: 11009 Comm: trace Kdump: loaded Not tainted 6.2.0+ #4
[ 867.843100] Call Trace:
[ 867.843101] <TASK>
[ 867.843104] asm_exc_int3+0x3a/0x40
[ 867.843108] RIP: 0010:preempt_count_sub+0x1/0xa0
[ 867.843135] __bpf_prog_enter_recur+0x17/0x90
[ 867.843148] bpf_trampoline_6442468108_0+0x2e/0x1000
[ 867.843154] ? preempt_count_sub+0x1/0xa0
[ 867.843157] preempt_count_sub+0x5/0xa0
[ 867.843159] ? migrate_enable+0xac/0xf0
[ 867.843164] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843168] bpf_trampoline_6442468108_0+0x55/0x1000
...
[ 867.843788] preempt_count_sub+0x5/0xa0
[ 867.843793] ? migrate_enable+0xac/0xf0
[ 867.843829] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843837] BUG: IRQ stack guard page was hit at 0000000099bd8228 (stack is 00000000b23e2bc4..000000006d95af35)
[ 867.843841] BUG: IRQ stack guard page was hit at 000000005ae07924 (stack is 00000000ffd69623..0000000014eb594c)
[ 867.843843] BUG: IRQ stack guard page was hit at 00000000028320f0 (stack is 00000000034b6438..0000000078d1bcec)
[ 867.843842] bpf_trampoline_6442468108_0+0x55/0x1000
...
That is because in __bpf_prog_exit_recur, the preempt_count_{sub,add} are
called after prog->active is decreased.
Fixing this by adding these two functions into btf ids deny list.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.12.11 – < 5.13, 5.13 | 5.13 |
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 | 6.3.7-1 | — |
| Debian 13 | linux | 6.3.7-1 | — |
| Debian 12 | linux | 6.1.37-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1023.25 | — |
| Ubuntu 24.04 LTS | linux-riscv +10 | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-83.92 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1044.49 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1046.53 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1046.53.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1041.49 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1041.46 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1027.32 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1037.40 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1039.45 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1032.32 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1017.17 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1004.4 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1042.48 | — |
| 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 | 5.15.0-1044.49~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1046.53~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1041.49~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-83.92~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1037.40~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1040.46~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1017.17~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1042.48~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1040.44~20.04.3 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 3 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 | 5.15.0-1038.40 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1045.50 | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips | No fix yet | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.34-56.100 | 1.0-0.amzn2023 | ALAS2023-2023-228 |
| Amazon Linux 2023 | perf +12 | 6.1.34-56.100.amzn2023 | ALAS2023-2023-228 |
Advisories 2
- WID-SEC-2025-2929 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- ALAS2023-2023-228 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026