Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take different parameters or return different return values. If
prog attached to one kernel function tail calls prog attached to another
kernel function, the ctx access or return value verification could be
bypassed.
For example, if prog1 is attached to func1 which takes only 1 parameter
and prog2 is attached to func2 which takes two parameters. Since verifier
assumes the bpf ctx passed to prog2 is constructed based on func2's
prototype, verifier allows prog2 to access the second parameter from
the bpf ctx passed to it. The problem is that verifier does not prevent
prog1 from passing its bpf ctx to prog2 via tail call. In this case,
the bpf ctx passed to prog2 is constructed from func1 instead of func2,
that is, the assumption for ctx access verification is bypassed.
Another example, if BPF LSM prog1 is attached to hook file_alloc_security,
and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier
knows the return value rules for these two hooks, e.g. it is legal for
bpf_lsm_audit_rule_known to return positive number 1, and it is illegal
for file_alloc_security to return positive number. So verifier allows
prog2 to return positive number 1, but does not allow prog1 to return
positive number. The problem is that verifier does not prevent prog1
from calling prog2 via tail call. In this case, prog2's return value 1
will be used as the return value for prog1's hook file_alloc_security.
That is, the return value rule is bypassed.
This patch adds restriction for tail call to prevent such bypasses.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.5 | 6.1.135 |
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 | 6.11.4-1 | — |
| Debian 13 | linux | 6.11.4-1 | — |
| Debian 12 | linux | 6.1.135-1 | DSA-5907-1 |
| Debian 11 | linux-6.1 | 6.1.137-1~deb11u1 | DLA-4193-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-56.58 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1025.27 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1025.30 | USN-7384-1 |
| Ubuntu 24.04 LTS | linux-azure-6.11 | 6.11.0-1012.12~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1014.15 | USN-7468-1 |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1026.28 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.11 | 6.11.0-1011.11~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1021.25 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1008.10 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1022.22 | USN-7385-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1024.27 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.11 | 6.11.0-1007.7 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1024.27.1 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1004.4 | — |
| Ubuntu 24.04 LTS | linux-oem-6.11 | 6.11.0-1015.15 | USN-7310-1 |
| Ubuntu 24.04 LTS | linux-oem-6.8 | 6.8.0-1024.24 | USN-7386-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1022.23 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1028.32 | USN-7524-1 |
| Ubuntu 24.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv +1 | 6.8.0-56.58.1 | USN-7383-1 |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1017.18 | — |
| Ubuntu 22.04 LTS | linux +49 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1027.29~22.04.1 | USN-7451-1 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1025.30~22.04.1 | USN-7384-2 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1026.28~22.04.1 | USN-7383-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-57.59~22.04.1 | USN-7403-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1023.23~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1024.27~22.04.1 | USN-7383-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1022.23~22.04.1 | USN-7383-1 |
| Ubuntu 22.04 LTS | linux-riscv-6.8 +1 | 6.8.0-56.58.1~22.04.1 | USN-7383-1 |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| 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 24.04 LTS | linux-raspi-realtime | 6.8.0-2023.24 | USN-7523-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1018.19 | USN-7383-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1018.19~22.04.1 | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-78.78+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 +10 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.30.1 | SUSE-SU-2024:4318-1 |
| SLES 15 SP6 | kernel-azure | 6.4.0-150600.8.17.2 | SUSE-SU-2024:3984-1 |
| SLES 15 SP6 | kernel-coco +3 | 6.4.0-15061.9.coco15sp6.1 | SUSE-SU-2024:4387-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.30.1.150600.12.12.6 | SUSE-SU-2024:4318-1 |
| SLES 15 SP6 | kernel-syms-azure +1 | 6.4.0-150600.8.17.1 | SUSE-SU-2024:3984-1 |
| SLES 15 SP5 | kernel-64kb +6 | 5.14.21-150500.55.88.1 | SUSE-SU-2024:4364-1 |
| SLES 15 SP5 | kernel-azure +2 | 5.14.21-150500.33.72.1 | SUSE-SU-2024:3983-1 |
| SLES 15 SP5 | kernel-default-base | 5.14.21-150500.55.88.1.150500.6.39.4 | SUSE-SU-2024:4364-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | kernel-default-base | 6.4.0-24.1.21.4 | SUSE-SU-2025:20247-1 |
| SLE Micro 6.1 | kernel-livepatch-MICRO-6-0-RT_Update_4 | 1-1.1 | SUSE-SU-2025:20246-1 |
| SLE Micro 6.1 | kernel-livepatch-MICRO-6-0_Update_4 | 1-1.2 | SUSE-SU-2025:20247-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-22.1 | SUSE-SU-2025:20246-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-24.1 | SUSE-SU-2025:20247-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-24.1.21.4 | SUSE-SU-2025:20164-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0-RT_Update_4 | 1-1.1 | SUSE-SU-2025:20163-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0_Update_4 | 1-1.2 | SUSE-SU-2025:20164-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-22.1 | SUSE-SU-2025:20163-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-24.1 | SUSE-SU-2025:20164-1 |
| SLE Micro 5.5 | kernel-default | 5.14.21-150500.55.88.1 | SUSE-SU-2024:4364-1 |
| SLE Micro 5.5 | kernel-default-base | 5.14.21-150500.55.88.1.150500.6.39.4 | SUSE-SU-2024:4364-1 |
| SLE Micro 5.5 | kernel-rt +1 | 5.14.21-150500.13.76.1 | SUSE-SU-2024:3985-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.30.1 | SUSE-SU-2024:4318-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_5 | 1-150600.1.3.1 | SUSE-SU-2024:3986-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_6 | 1-150600.13.3.5 | SUSE-SU-2024:4318-1 |
| SLE Live Patching 15 SP5 | kernel-default | 5.14.21-150500.55.88.1 | SUSE-SU-2024:4364-1 |
| SLE Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5-RT_Update_22 | 1-150500.11.3.1 | SUSE-SU-2024:3985-1 |
| SLE Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_21 | 1-150500.11.5.1 | SUSE-SU-2024:4364-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.17.1 | SUSE-SU-2024:3986-1 |
| SUSE Real Time Module 15 SP5 | kernel-rt +3 | 5.14.21-150500.13.76.1 | SUSE-SU-2024:3985-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 6.11.8-1.1 | openSUSE-SU-2024:14500-1 |
| openSUSE Tumbleweed | kernel-source-longterm | 6.12.11-1.1 | openSUSE-SU-2025:14705-1 |
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.30.1 | SUSE-SU-2024:4318-1 |
| openSUSE Leap 15.6 | kernel-azure | 6.4.0-150600.8.17.2 | SUSE-SU-2024:3984-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.30.1.150600.12.12.6 | SUSE-SU-2024:4318-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.17.1 | SUSE-SU-2024:3986-1 |
| openSUSE Leap 15.6 | kernel-syms-azure +1 | 6.4.0-150600.8.17.1 | SUSE-SU-2024:3984-1 |
| openSUSE Leap 15.5 | kernel-azure +2 | 5.14.21-150500.33.72.1 | SUSE-SU-2024:3983-1 |
| openSUSE Leap 15.5 | kernel-rt +3 | 5.14.21-150500.13.76.1 | SUSE-SU-2024:3985-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap Micro 5.5 | kernel-rt | 5.14.21-150500.13.76.1 | SUSE-SU-2024:3985-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.140-154.222 | 1.0-0.amzn2023 | ALAS2023-2025-1050 |
| Amazon Linux 2023 | perf +14 | 6.1.140-154.222.amzn2023 | ALAS2023-2025-1050 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | kernel | 5.15.173.1-1 | — |
Advisories 33
- WID-SEC-2024-3251 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 11, 2026
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- USN-7468-1 linux-azure-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7451-1 linux-aws-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7524-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7523-1 linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7310-1 linux-oem-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7384-2 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- USN-7384-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- USN-7383-1 linux, linux-aws, linux-gcp, linux-gcp-6.8, linux-gke, linux-gkeop, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7386-1 linux-oem-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7383-2 linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7403-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7385-1 linux-ibm vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- ICSA-26-295-11 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Oct 22, 2026
- SSA-019113 SSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6 Siemens ProductCERT · Oct 13, 2026
- ICSA-26-209-04 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Jul 28, 2026
- SUSE-SU-2025:20163-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20246-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20164-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20247-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- DSA-5907-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4193-1 linux-6.1 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2024:3985-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4318-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3984-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3986-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4364-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14705-1 kernel-devel-longterm-6.12.11-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14500-1 kernel-devel-6.11.8-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4387-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3983-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2025-1050 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 26, 2025