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Fencer Vulns
medium 5.5

CVE-2022-49402 json

ftrace: Clean up hash direct_functions on register failures

published 2025-02-26 20 mo ago modified 2026-11-05 3 d ago also EUVD-2022-54827

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

ftrace: Clean up hash direct_functions on register failures

We see the following GPF when register_ftrace_direct fails:

[ ] general protection fault, probably for non-canonical address \ 0x200000000000010: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [...] [ ] RIP: 0010:ftrace_find_rec_direct+0x53/0x70 [ ] Code: 48 c1 e0 03 48 03 42 08 48 8b 10 31 c0 48 85 d2 74 [...] [ ] RSP: 0018:ffffc9000138bc10 EFLAGS: 00010206 [ ] RAX: 0000000000000000 RBX: ffffffff813e0df0 RCX: 000000000000003b [ ] RDX: 0200000000000000 RSI: 000000000000000c RDI: ffffffff813e0df0 [ ] RBP: ffffffffa00a3000 R08: ffffffff81180ce0 R09: 0000000000000001 [ ] R10: ffffc9000138bc18 R11: 0000000000000001 R12: ffffffff813e0df0 [ ] R13: ffffffff813e0df0 R14: ffff888171b56400 R15: 0000000000000000 [ ] FS: 00007fa9420c7780(0000) GS:ffff888ff6a00000(0000) knlGS:000000000 [ ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ ] CR2: 000000000770d000 CR3: 0000000107d50003 CR4: 0000000000370ee0 [ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ ] Call Trace: [ ] <TASK> [ ] register_ftrace_direct+0x54/0x290 [ ] ? render_sigset_t+0xa0/0xa0 [ ] bpf_trampoline_update+0x3f5/0x4a0 [ ] ? 0xffffffffa00a3000 [ ] bpf_trampoline_link_prog+0xa9/0x140 [ ] bpf_tracing_prog_attach+0x1dc/0x450 [ ] bpf_raw_tracepoint_open+0x9a/0x1e0 [ ] ? find_held_lock+0x2d/0x90 [ ] ? lock_release+0x150/0x430 [ ] __sys_bpf+0xbd6/0x2700 [ ] ? lock_is_held_type+0xd8/0x130 [ ] __x64_sys_bpf+0x1c/0x20 [ ] do_syscall_64+0x3a/0x80 [ ] entry_SYSCALL_64_after_hwframe+0x44/0xae [ ] RIP: 0033:0x7fa9421defa9 [ ] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 9 f8 [...] [ ] RSP: 002b:00007ffed743bd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ ] RAX: ffffffffffffffda RBX: 00000000069d2480 RCX: 00007fa9421defa9 [ ] RDX: 0000000000000078 RSI: 00007ffed743bd80 RDI: 0000000000000011 [ ] RBP: 00007ffed743be00 R08: 0000000000bb7270 R09: 0000000000000000 [ ] R10: 00000000069da210 R11: 0000000000000246 R12: 0000000000000001 [ ] R13: 00007ffed743c4b0 R14: 00000000069d2480 R15: 0000000000000001 [ ] </TASK> [ ] Modules linked in: klp_vm(OK) [ ] ---[ end trace 0000000000000000 ]---

One way to trigger this is: 1. load a livepatch that patches kernel function xxx; 2. run bpftrace -e 'kfunc:xxx {}', this will fail (expected for now); 3. repeat #2 => gpf.

This is because the entry is added to direct_functions, but not removed. Fix this by remove the entry from direct_functions when register_ftrace_direct fails.

Also remove the last trailing space from ftrace.c, so we don't have to worry about it anymore.

Patch / fix

  • Linux Linux 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.19
  • linux Debian 14, Debian 13, Debian 12 5.18.5-1

debian advisories DEBIAN-CVE-2022-49402

  • linux Ubuntu 22.04 LTS 5.15.0-47.51
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1019.23
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1017.23
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1015.18
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1013.15
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1017.21
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1019.24
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1002.4

ubuntu advisories UBUNTU-CVE-2022-49402

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.201.1
  • kernel-syms SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.201.1
  • kernel-source SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.201.1
  • kernel-default SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +5 more 5.3.18-150300.59.201.1
  • kernel-preempt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.201.1
  • kernel-obs-build SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.201.1
  • kernel-default-base SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +3 more 5.3.18-150300.59.201.1.150300.18.120.1
  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.100.1

suse advisories SUSE-SU-2025:1263-1SUSE-SU-2025:1241-1SUSE-SU-2025:1194-1SUSE-SU-2025:1183-1SUSE-SU-2025:1176-1SUSE-SU-2025:1027-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49402 updated cvss 4.4

kernel: ftrace: Clean up hash direct_functions on register failures

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 d ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.