{ "schema_version": "1.6.1", "id": "RPI-CVE-2023-52447", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2023-52447" ], "published": "2024-02-22T16:22:12Z", "summary": "bpf: Defer the free of inner map when necessary", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Defer the free of inner map when necessary\n\nWhen updating or deleting an inner map in map array or map htab, the map\nmay still be accessed by non-sleepable program or sleepable program.\nHowever bpf_map_fd_put_ptr() decreases the ref-counter of the inner map\ndirectly through bpf_map_put(), if the ref-counter is the last one\n(which is true for most cases), the inner map will be freed by\nops->map_free() in a kworker. But for now, most .map_free() callbacks\ndon't use synchronize_rcu() or its variants to wait for the elapse of a\nRCU grace period, so after the invocation of ops->map_free completes,\nthe bpf program which is accessing the inner map may incur\nuse-after-free problem.\n\nFix the free of inner map by invoking bpf_map_free_deferred() after both\none RCU grace period and one tasks trace RCU grace period if the inner\nmap has been removed from the outer map before. The deferment is\naccomplished by using call_rcu() or call_rcu_tasks_trace() when\nreleasing the last ref-counter of bpf map. The newly-added rcu_head\nfield in bpf_map shares the same storage space with work field to\nreduce the size of bpf_map.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.21-1+rpt1", "1:6.1.47-1+rpt2", "1:6.1.47-1+rpt4", "1:6.1.54-1+rpt2", "1:6.1.58-1+rpt2", "1:6.1.63-1+rpt1", "1:6.1.73-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi1-rpi-v6", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v8", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v6", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7l", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v8", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-2712", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v6", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7l", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v8", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-2712", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v6", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7l", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v8", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-2712", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v6", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7l", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v8", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-2712", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v6", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7l", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v8", "binary_version": "1:6.1.73-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.1.21-1+rpt1": { "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed", "upstream_version": "6.1.21", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.47-1+rpt2": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75", "compiled_filter": false }, "1:6.1.54-1+rpt2": { "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7", "upstream_version": "6.1.54", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.58-1+rpt2": { "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18", "upstream_version": "6.1.58", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.63-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.63", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.75" }, "1:6.1.73-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.73", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.75" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2023-52447" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/90c445799fd1dc214d7c6279c144e33a35e29ef2" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/37d98fb9c3144c0fddf7f6e99aece9927ac8dce6" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/62fca83303d608ad4fec3f7428c8685680bb01b0" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/f91cd728b10c51f6d4a39957ccd56d1e802fc8ee" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/bfd9b20c4862f41d4590fde11d70a5eeae53dcc5" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/876673364161da50eed6b472d746ef88242b2368" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T11:24:39Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The bug is reached only through the local bpf() syscall (BPF_MAP_UPDATE_ELEM/DELETE_ELEM on ARRAY_OF_MAPS or HASH_OF_MAPS while a concurrently running BPF program holds the old inner map); there is no network or adjacent-protocol path into bpf_map_fd_put_ptr().\nAC:L - The attacker fully controls both sides of the race\u2014one thread updating/deleting the outer map entry while another triggers the attached BPF program (as demonstrated by the upstream map_in_map selftest)\u2014so no attacker-uncontrollable timing or memory-layout condition is required.\nPR:L - ARRAY_OF_MAPS/HASH_OF_MAPS are in map_create()'s explicitly unprivileged branch, and with unprivileged_bpf_disabled=0 (default on affected 5.9\u20135.15 kernels and common on Android/embedded) a plain local user can create them and drive the UAF via SOCKET_FILTER; CAP_BPF is otherwise a delegatable non-root capability routinely granted to containers and agents.\nUI:N - The attacker creates the maps, loads/attaches the program, and performs the concurrent update/delete themselves; no separate victim action is required.\nS:U - This is a standard host-kernel use-after-free privilege escalation within the same OS security authority, with no VM escape, IOMMU bypass, or other cross-boundary impact.\nC:H - The inner map (e.g. bpf_array) is freed via array_map_free()/htab_map_free() while a BPF program still dereferences it (KASAN slab-UAF), giving the attacker control over a reclaimable kernel object and enabling arbitrary read primitives.\nI:H - The same heap UAF of the inner map object is sprayable and exploitable for arbitrary write and control-flow hijacking once the freed map memory is reclaimed under attacker control.\nA:H - Even without a full exploit, concurrent use of the prematurely freed inner map causes kernel oops/KASAN faults (as shown in the selftest report in array_map_update_elem), fully denying availability." } } }