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CVE-2026-98611
bpf: Check params size before reading reserved fields
Published 2026-10-18 (today) by the Linux kernel CNA. Subsystem kernel/bpf. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-98611 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | fixed | 6.12.113-1 | Update the kernel and reboot. Fixed in 6.12.113-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.9-1 | Update the kernel and reboot. Fixed in 7.2.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.9-1 | Update the kernel and reboot. Fixed in 7.2.9-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
bpf_crypto_ctx_create() is a kfunc whose second argument is declared with the __sz annotation, so the verifier only guarantees that params__sz bytes of params are valid. The function nevertheless reads params->reserved[0] and params->reserved[1] (offsets 14 and 15) before comparing params__sz against the size of struct bpf_crypto_params, so a BPF program can pass a shorter buffer and have the kernel read past the region that was validated for it. Move the size check in front of the reserved field reads.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
kernel/bpf/crypto.c
- What this is
- BPF [CRYPTO]MAINTAINERS section matched on kernel/bpf/crypto.c · bpf@vger.kernel.org · Maintained
Check it on the machine
grep -wE 'CONFIG_BPF|CONFIG_BPF_SYSCALL' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian builds this code. Every release with an answer below compiles the affected file into the kernels it ships. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixie, forky, sidy
- ?
- not established - no Makefile entry for the affected file
- y
- built into the kernel image on every flavour - only a patch removes it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switches
- CONFIG_BPF, CONFIG_BPF_SYSCALL
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-10-18 (today)source
- CVSS
- no vector published, unrated
- Attack vector
- not published
- EPSS
- not scored
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- kernel/bpf
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.10 | 6.12.112 | e03253f5d65e |
| 6.10 | 6.18.55 | cd12d3e08620 |
| 6.10 | 7.2.9 | 86a0e945fb64 |
| 6.10 | 7.3 | a11212910cf0 |
Why the CNA scored it this way
The kernel CNA published no CVSS vector and no reasoning for CVE-2026-98611, which is why it is shown as unrated rather than given an invented score. 6,405 of the 20,413 CVEs here carry reasoning; this is not one of them.