In the Linux kernel, the following vulnerability has been resolved: bpf: Defer the free of inner map when necessary When updating or deleting an inner map in map array or map htab, the map may still be accessed by non-sleepable program or sleepable program. However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map directly through bpf_map_put(), if the ref-counter is the last one (which is true for most cases), the inner map will be freed by ops->map_free() in a kworker. But for now, most .map_free() callbacks don't use synchronize_rcu() or its variants to wait for the elapse of a RCU grace period, so after the invocation of ops->map_free completes, the bpf program which is accessing the inner map may incur use-after-free problem. Fix the free of inner map by invoking bpf_map_free_deferred() after both one RCU grace period and one tasks trace RCU grace period if the inner map has been removed from the outer map before. The deferment is accomplished by using call_rcu() or call_rcu_tasks_trace() when releasing the last ref-counter of bpf map. The newly-added rcu_head field in bpf_map shares the same storage space with work field to reduce the size of bpf_map.
History

Mon, 04 Nov 2024 13:45:00 +0000

Type Values Removed Values Added
References

Tue, 15 Oct 2024 21:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:5.9:*:*:*:*:*:*:*
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 07 Oct 2024 18:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 6.7, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-02-22T16:21:39.032Z

Updated: 2024-11-04T14:46:53.851Z

Reserved: 2024-02-20T12:30:33.292Z

Link: CVE-2023-52447

cve-icon Vulnrichment

Updated: 2024-08-02T22:55:41.700Z

cve-icon NVD

Status : Modified

Published: 2024-02-22T17:15:08.580

Modified: 2024-11-04T13:16:29.427

Link: CVE-2023-52447

cve-icon Redhat

Severity : Low

Publid Date: 2024-02-22T00:00:00Z

Links: CVE-2023-52447 - Bugzilla