{"id":"CVE-2023-52928","state":"PUBLISHED","title":"bpf: Skip invalid kfunc call in backtrack_insn","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Skip invalid kfunc call in backtrack_insn\n\nThe verifier skips invalid kfunc call in check_kfunc_call(), which\nwould be captured in fixup_kfunc_call() if such insn is not eliminated\nby dead code elimination. However, this can lead to the following\nwarning in backtrack_insn(), also see [1]:\n\n  ------------[ cut here ]------------\n  verifier backtracking bug\n  WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn\n  kernel/bpf/verifier.c:2756\n\t__mark_chain_precision kernel/bpf/verifier.c:3065\n\tmark_chain_precision kernel/bpf/verifier.c:3165\n\tadjust_reg_min_max_vals kernel/bpf/verifier.c:10715\n\tcheck_alu_op kernel/bpf/verifier.c:10928\n\tdo_check kernel/bpf/verifier.c:13821 [inline]\n\tdo_check_common kernel/bpf/verifier.c:16289\n  [...]\n\nSo make backtracking conservative with this by returning ENOTSUPP.\n\n  [1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/","publishedAt":"2025-03-27T16:37:10.471Z","updatedAt":"2026-05-11T19:35:53.339Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e6ac2450d6dee3121cd8bbf2907b78a68a8a353d","status":"affected","lessThan":"6e2fac197de2c4c041bdd8982cffb104689113f1","versionType":"git"},{"version":"e6ac2450d6dee3121cd8bbf2907b78a68a8a353d","status":"affected","lessThan":"74eec8266f37aff609db6a2f2b093e56a11c28c4","versionType":"git"},{"version":"e6ac2450d6dee3121cd8bbf2907b78a68a8a353d","status":"affected","lessThan":"d3178e8a434b58678d99257c0387810a24042fb6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.93","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.11","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":["https://git.kernel.org/stable/c/6e2fac197de2c4c041bdd8982cffb104689113f1","https://git.kernel.org/stable/c/74eec8266f37aff609db6a2f2b093e56a11c28c4","https://git.kernel.org/stable/c/d3178e8a434b58678d99257c0387810a24042fb6"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/52xxx/CVE-2023-52928.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-52928","state":"PUBLISHED","datePublished":"2025-03-27T16:37:10.471Z","dateUpdated":"2026-05-11T19:35:53.339Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T06:07:11.018Z"},"containers":{"cna":{"title":"bpf: Skip invalid kfunc call in backtrack_insn","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Skip invalid kfunc call in backtrack_insn\n\nThe verifier skips invalid kfunc call in check_kfunc_call(), which\nwould be captured in fixup_kfunc_call() if such insn is not eliminated\nby dead code elimination. However, this can lead to the following\nwarning in backtrack_insn(), also see [1]:\n\n  ------------[ cut here ]------------\n  verifier backtracking bug\n  WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn\n  kernel/bpf/verifier.c:2756\n\t__mark_chain_precision kernel/bpf/verifier.c:3065\n\tmark_chain_precision kernel/bpf/verifier.c:3165\n\tadjust_reg_min_max_vals kernel/bpf/verifier.c:10715\n\tcheck_alu_op kernel/bpf/verifier.c:10928\n\tdo_check kernel/bpf/verifier.c:13821 [inline]\n\tdo_check_common kernel/bpf/verifier.c:16289\n  [...]\n\nSo make backtracking conservative with this by returning ENOTSUPP.\n\n  [1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e6ac2450d6dee3121cd8bbf2907b78a68a8a353d","status":"affected","lessThan":"6e2fac197de2c4c041bdd8982cffb104689113f1","versionType":"git"},{"version":"e6ac2450d6dee3121cd8bbf2907b78a68a8a353d","status":"affected","lessThan":"74eec8266f37aff609db6a2f2b093e56a11c28c4","versionType":"git"},{"version":"e6ac2450d6dee3121cd8bbf2907b78a68a8a353d","status":"affected","lessThan":"d3178e8a434b58678d99257c0387810a24042fb6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.93","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.11","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/6e2fac197de2c4c041bdd8982cffb104689113f1"},{"url":"https://git.kernel.org/stable/c/74eec8266f37aff609db6a2f2b093e56a11c28c4"},{"url":"https://git.kernel.org/stable/c/d3178e8a434b58678d99257c0387810a24042fb6"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:35:53.339Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.1.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}