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CVE-2026-43409
kprobes: avoid crash when rmmod/insmod after ftrace killed
Published 2026-05-08 (5 months ago) by the Linux kernel CNA. Subsystem kernel. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-43409 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 | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixed | 6.12.85-1 | Update the kernel and reboot. Fixed in 6.12.85-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.19.10-1 | Update the kernel and reboot. Fixed in 6.19.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.19.10-1 | Update the kernel and reboot. Fixed in 6.19.10-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
After we hit ftrace is killed by some errors, the kernel crash if we remove modules in which kprobe probes. BUG: unable to handle page fault for address: fffffbfff805000d PGD 817fcc067 P4D 817fcc067 PUD 817fc8067 PMD 101555067 PTE 0 Oops: Oops: 0000 [#1] SMP KASAN PTI CPU: 4 UID: 0 PID: 2012 Comm: rmmod Tainted: G W OE Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE RIP: 0010:kprobes_module_callback+0x89/0x790 RSP: 0018:ffff88812e157d30 EFLAGS: 00010a02 RAX: 1ffffffff805000d RBX: dffffc0000000000 RCX: ffffffff86a8de90 RDX: ffffed1025c2af9b RSI: 0000000000000008 RDI: ffffffffc0280068 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1025c2af9a R10: ffff88812e157cd7 R11: 205d323130325420 R12: 0000000000000002 R13: ffffffffc0290488 R14: 0000000000000002 R15: ffffffffc0280040 FS: 00007fbc450dd740(0000) GS:ffff888420331000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff805000d CR3: 000000010f624000 CR4: 00000000000006f0 Call Trace: <TASK> notifier_call_chain+0xc6/0x280 blocking_notifier_call_chain+0x60/0x90 __do_sys_delete_module.constprop.0+0x32a/0x4e0 do_syscall_64+0x5d/0xfa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e This is because the kprobe on ftrace does not correctly handles the kprobe_ftrace_disabled flag set by ftrace_kill(). To prevent this error, check kprobe_ftrace_disabled in __disarm_kprobe_ftrace() and skip all ftrace related operations.
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/kprobes.c
- What this is
- KPROBESMAINTAINERS section matched on kernel/kprobes.c · linux-kernel@vger.kernel.org · Maintained
Check it on the machine
grep -w CONFIG_KPROBES /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 below compiles the affected file into the kernels it ships.
- bookworm, trixie, forky, sidy
- y
- built into the kernel image on every flavour - only a patch removes it
- Build switch
- CONFIG_KPROBES
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
- 2026-05-08 (5 months ago)source
- CVSS
- no vector published, unrated
- Attack vector
- not published
- EPSS
- 0.12%, higher than 1.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- kernel
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 3.7 | 6.6.130 | 8b6767e4141b |
| 3.7 | 6.12.78 | b0ca81616a01 |
| 3.7 | 6.18.19 | cae928e3178c |
| 3.7 | 6.19.9 | 9edc79d66483 |
| 3.7 | 7.0 | e113f0b46d19 |
Why the CNA scored it this way
The kernel CNA published no CVSS vector and no reasoning for CVE-2026-43409, 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.