{"id":"CVE-2023-52447","state":"PUBLISHED","title":"bpf: Defer the free of inner map when necessary","description":"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.","publishedAt":"2024-02-22T16:21:39.032Z","updatedAt":"2026-10-15T00:16:57.695Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"90c445799fd1dc214d7c6279c144e33a35e29ef2","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"37d98fb9c3144c0fddf7f6e99aece9927ac8dce6","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"62fca83303d608ad4fec3f7428c8685680bb01b0","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"f91cd728b10c51f6d4a39957ccd56d1e802fc8ee","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"bfd9b20c4862f41d4590fde11d70a5eeae53dcc5","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"876673364161da50eed6b472d746ef88242b2368","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf.h","kernel/bpf/map_in_map.c","kernel/bpf/syscall.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.9","versionType":"semver"},{"version":"5.10.214","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.153","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.75","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.14","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.2","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf.h","kernel/bpf/map_in_map.c","kernel/bpf/syscall.c"]}],"references":["https://git.kernel.org/stable/c/90c445799fd1dc214d7c6279c144e33a35e29ef2","https://git.kernel.org/stable/c/37d98fb9c3144c0fddf7f6e99aece9927ac8dce6","https://git.kernel.org/stable/c/62fca83303d608ad4fec3f7428c8685680bb01b0","https://git.kernel.org/stable/c/f91cd728b10c51f6d4a39957ccd56d1e802fc8ee","https://git.kernel.org/stable/c/bfd9b20c4862f41d4590fde11d70a5eeae53dcc5","https://git.kernel.org/stable/c/876673364161da50eed6b472d746ef88242b2368","https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html","https://cert-portal.siemens.com/productcert/html/ssa-265688.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/52xxx/CVE-2023-52447.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-52447","state":"PUBLISHED","datePublished":"2024-02-22T16:21:39.032Z","dateUpdated":"2026-10-15T00:16:57.695Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-02-20T12:30:33.292Z"},"containers":{"cna":{"title":"bpf: Defer the free of inner map when necessary","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"90c445799fd1dc214d7c6279c144e33a35e29ef2","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"37d98fb9c3144c0fddf7f6e99aece9927ac8dce6","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"62fca83303d608ad4fec3f7428c8685680bb01b0","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"f91cd728b10c51f6d4a39957ccd56d1e802fc8ee","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"bfd9b20c4862f41d4590fde11d70a5eeae53dcc5","versionType":"git"},{"version":"bba1dc0b55ac462d24ed1228ad49800c238cd6d7","status":"affected","lessThan":"876673364161da50eed6b472d746ef88242b2368","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf.h","kernel/bpf/map_in_map.c","kernel/bpf/syscall.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.9","versionType":"semver"},{"version":"5.10.214","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.153","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.75","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.14","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.2","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/bpf.h","kernel/bpf/map_in_map.c","kernel/bpf/syscall.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/90c445799fd1dc214d7c6279c144e33a35e29ef2"},{"url":"https://git.kernel.org/stable/c/37d98fb9c3144c0fddf7f6e99aece9927ac8dce6"},{"url":"https://git.kernel.org/stable/c/62fca83303d608ad4fec3f7428c8685680bb01b0"},{"url":"https://git.kernel.org/stable/c/f91cd728b10c51f6d4a39957ccd56d1e802fc8ee"},{"url":"https://git.kernel.org/stable/c/bfd9b20c4862f41d4590fde11d70a5eeae53dcc5"},{"url":"https://git.kernel.org/stable/c/876673364161da50eed6b472d746ef88242b2368"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L 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