CVE-2026-74314
bpf: Cancel special fields on map value recycle
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Cancel special fields on map value recycle Map update and delete paths currently call bpf_obj_free_fields() when a value is being replaced or recycled. That makes field destruction depend on the context of the update/delete operation. For tracing programs this can include NMI context, where referenced kptr destructors, uptr unpinning, and graph root destruction are not generally safe. Introduce bpf_obj_cancel_fields() for the reusable-value path. It only performs NMI-safe cleanup for timer, workqueue, and task_work fields. Fields that need full destruction are left attached to the recycled value and are destroyed by the final cleanup path instead. Switch array and hashtab update/delete/recycle paths to this cancel helper. Keep bpf_obj_free_fields() for final map destruction and for bpf_mem_alloc destructors. Preallocated hashtabs do not have allocator destructors, so teardown continues to walk the normal and extra elements and fully destroy their fields. This deliberately relaxes the eager-free semantics of map update/delete for special fields. Programs that relied on a recycled map slot becoming empty immediately after update/delete were relying on behavior that cannot be implemented safely from every BPF execution context without offloading arbitrary destructors. There is a chance this change breaks programs making assumptions regarding the eager freeing of fields. If so, we can relax semantics to cancellation only when irqs_disabled() is true in the future. However, theoretically, map values that get reused eagerly already have weaker guarantees as parallel users can recreate freed fields before the new element becomes visible again.
INFO
Published Date :
Aug. 15, 2026, 6:22 a.m.
Last Modified :
Aug. 17, 2026, 6:19 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel.
- Review programs for assumptions about eager field freeing.
- Consider relaxing semantics if irqs_disabled() is true.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-74314.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/9ea734e2cc0143d7429ab7dc0b20c85e5836183c | |
| https://git.kernel.org/stable/c/a3a81d247651218e47153f2d2afd7aee236726fd |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74314 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74314
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74314 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74314 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '14a324f6a67ef6a53e04362a70160a47eb8afffa', 'lessThan': '9ea734e2cc0143d7429ab7dc0b20c85e5836183c', 'versionType': 'git'}, {'status': 'affected', 'version': '14a324f6a67ef6a53e04362a70160a47eb8afffa', 'lessThan': 'a3a81d247651218e47153f2d2afd7aee236726fd', 'versionType': 'git'}, {'status': 'affected', 'version': 'f0462d38589422bc9e27fd3c6343dfeb6b3db2f9', 'versionType': 'git'}, {'status': 'affected', 'version': '5.18.18', 'lessThan': '5.19', 'versionType': 'semver'}], 'programFiles': ['include/linux/bpf.h', 'kernel/bpf/arraymap.c', 'kernel/bpf/hashtab.c', 'kernel/bpf/syscall.c', 'tools/testing/selftests/bpf/prog_tests/htab_update.c', 'tools/testing/selftests/bpf/prog_tests/linked_list.c', 'tools/testing/selftests/bpf/prog_tests/map_kptr.c', 'tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c', 'tools/testing/selftests/bpf/progs/htab_update.c', 'tools/testing/selftests/bpf/progs/linked_list.c', 'tools/testing/selftests/bpf/progs/refcounted_kptr.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/linux/bpf.h', 'kernel/bpf/arraymap.c', 'kernel/bpf/hashtab.c', 'kernel/bpf/syscall.c', 'tools/testing/selftests/bpf/prog_tests/htab_update.c', 'tools/testing/selftests/bpf/prog_tests/linked_list.c', 'tools/testing/selftests/bpf/prog_tests/map_kptr.c', 'tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c', 'tools/testing/selftests/bpf/progs/htab_update.c', 'tools/testing/selftests/bpf/progs/linked_list.c', 'tools/testing/selftests/bpf/progs/refcounted_kptr.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '14a324f6a67ef6a53e04362a70160a47eb8afffa', 'lessThan': '9ea734e2cc0143d7429ab7dc0b20c85e5836183c', 'versionType': 'git'}, {'status': 'affected', 'version': '14a324f6a67ef6a53e04362a70160a47eb8afffa', 'lessThan': 'a3a81d247651218e47153f2d2afd7aee236726fd', 'versionType': 'git'}, {'status': 'affected', 'version': 'f0462d38589422bc9e27fd3c6343dfeb6b3db2f9', 'versionType': 'git'}, {'status': 'affected', 'version': '5.18.18', 'lessThan': '5.19', 'versionType': 'semver'}], 'programFiles': ['include/linux/bpf.h', 'kernel/bpf/arraymap.c', 'kernel/bpf/hashtab.c', 'kernel/bpf/syscall.c', 'tools/testing/selftests/bpf/prog_tests/htab_update.c', 'tools/testing/selftests/bpf/prog_tests/linked_list.c', 'tools/testing/selftests/bpf/prog_tests/map_kptr.c', 'tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c', 'tools/testing/selftests/bpf/progs/htab_update.c', 'tools/testing/selftests/bpf/progs/linked_list.c', 'tools/testing/selftests/bpf/progs/refcounted_kptr.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/linux/bpf.h', 'kernel/bpf/arraymap.c', 'kernel/bpf/hashtab.c', 'kernel/bpf/syscall.c', 'tools/testing/selftests/bpf/prog_tests/htab_update.c', 'tools/testing/selftests/bpf/prog_tests/linked_list.c', 'tools/testing/selftests/bpf/prog_tests/map_kptr.c', 'tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c', 'tools/testing/selftests/bpf/progs/htab_update.c', 'tools/testing/selftests/bpf/progs/linked_list.c', 'tools/testing/selftests/bpf/progs/refcounted_kptr.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 15, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '14a324f6a67ef6a53e04362a70160a47eb8afffa', 'lessThan': '9ea734e2cc0143d7429ab7dc0b20c85e5836183c', 'versionType': 'git'}, {'status': 'affected', 'version': '14a324f6a67ef6a53e04362a70160a47eb8afffa', 'lessThan': 'a3a81d247651218e47153f2d2afd7aee236726fd', 'versionType': 'git'}, {'status': 'affected', 'version': 'f0462d38589422bc9e27fd3c6343dfeb6b3db2f9', 'versionType': 'git'}, {'status': 'affected', 'version': '5.18.18', 'lessThan': '5.19', 'versionType': 'semver'}], 'programFiles': ['include/linux/bpf.h', 'kernel/bpf/arraymap.c', 'kernel/bpf/hashtab.c', 'kernel/bpf/syscall.c', 'tools/testing/selftests/bpf/prog_tests/htab_update.c', 'tools/testing/selftests/bpf/prog_tests/linked_list.c', 'tools/testing/selftests/bpf/prog_tests/map_kptr.c', 'tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c', 'tools/testing/selftests/bpf/progs/htab_update.c', 'tools/testing/selftests/bpf/progs/linked_list.c', 'tools/testing/selftests/bpf/progs/refcounted_kptr.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/linux/bpf.h', 'kernel/bpf/arraymap.c', 'kernel/bpf/hashtab.c', 'kernel/bpf/syscall.c', 'tools/testing/selftests/bpf/prog_tests/htab_update.c', 'tools/testing/selftests/bpf/prog_tests/linked_list.c', 'tools/testing/selftests/bpf/prog_tests/map_kptr.c', 'tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c', 'tools/testing/selftests/bpf/progs/htab_update.c', 'tools/testing/selftests/bpf/progs/linked_list.c', 'tools/testing/selftests/bpf/progs/refcounted_kptr.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: bpf: Cancel special fields on map value recycle Map update and delete paths currently call bpf_obj_free_fields() when a value is being replaced or recycled. That makes field destruction depend on the context of the update/delete operation. For tracing programs this can include NMI context, where referenced kptr destructors, uptr unpinning, and graph root destruction are not generally safe. Introduce bpf_obj_cancel_fields() for the reusable-value path. It only performs NMI-safe cleanup for timer, workqueue, and task_work fields. Fields that need full destruction are left attached to the recycled value and are destroyed by the final cleanup path instead. Switch array and hashtab update/delete/recycle paths to this cancel helper. Keep bpf_obj_free_fields() for final map destruction and for bpf_mem_alloc destructors. Preallocated hashtabs do not have allocator destructors, so teardown continues to walk the normal and extra elements and fully destroy their fields. This deliberately relaxes the eager-free semantics of map update/delete for special fields. Programs that relied on a recycled map slot becoming empty immediately after update/delete were relying on behavior that cannot be implemented safely from every BPF execution context without offloading arbitrary destructors. There is a chance this change breaks programs making assumptions regarding the eager freeing of fields. If so, we can relax semantics to cancellation only when irqs_disabled() is true in the future. However, theoretically, map values that get reused eagerly already have weaker guarantees as parallel users can recreate freed fields before the new element becomes visible again. Added Reference https://git.kernel.org/stable/c/9ea734e2cc0143d7429ab7dc0b20c85e5836183c Added Reference https://git.kernel.org/stable/c/a3a81d247651218e47153f2d2afd7aee236726fd