{"id":"CVE-2023-53624","state":"PUBLISHED","title":"net/sched: sch_fq: fix integer overflow of \"credit\"","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_fq: fix integer overflow of \"credit\"\n\nif sch_fq is configured with \"initial quantum\" having values greater than\nINT_MAX, the first assignment of \"credit\" does signed integer overflow to\na very negative value.\nIn this situation, the syzkaller script provided by Cristoph triggers the\nCPU soft-lockup warning even with few sockets. It's not an infinite loop,\nbut \"credit\" wasn't probably meant to be minus 2Gb for each new flow.\nCapping \"initial quantum\" to INT_MAX proved to fix the issue.\n\nv2: validation of \"initial quantum\" is done in fq_policy, instead of open\n    coding in fq_change() _ suggested by Jakub Kicinski","publishedAt":"2025-10-07T15:19:29.545Z","updatedAt":"2026-05-11T19:48:45.406Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"4b8a05e3801661a0438fcd0cdef181030d966a5a","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"d0b43125ec892aeb1b03e5df5aab595097da225a","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"4fbefeab88c6e79753a25099d455d3d59d2946b4","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"85f24cb2f10b2b0f2882e5786a09b4790bb3a0ad","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"2322462d6f9ad4874f4e3c63df3b5cc00cb1acbd","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"7041101ff6c3073fd8f2e99920f535b111c929cb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_fq.c","tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.12","versionType":"semver"},{"version":"5.10.180","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.111","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.28","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.15","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3.2","status":"unaffected","lessThanOrEqual":"6.3.*","versionType":"semver"},{"version":"6.4","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_fq.c","tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json"]}],"references":["https://git.kernel.org/stable/c/4b8a05e3801661a0438fcd0cdef181030d966a5a","https://git.kernel.org/stable/c/d0b43125ec892aeb1b03e5df5aab595097da225a","https://git.kernel.org/stable/c/4fbefeab88c6e79753a25099d455d3d59d2946b4","https://git.kernel.org/stable/c/85f24cb2f10b2b0f2882e5786a09b4790bb3a0ad","https://git.kernel.org/stable/c/2322462d6f9ad4874f4e3c63df3b5cc00cb1acbd","https://git.kernel.org/stable/c/7041101ff6c3073fd8f2e99920f535b111c929cb"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53624.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53624","state":"PUBLISHED","datePublished":"2025-10-07T15:19:29.545Z","dateUpdated":"2026-05-11T19:48:45.406Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-10-07T15:16:59.655Z"},"containers":{"cna":{"title":"net/sched: sch_fq: fix integer overflow of \"credit\"","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_fq: fix integer overflow of \"credit\"\n\nif sch_fq is configured with \"initial quantum\" having values greater than\nINT_MAX, the first assignment of \"credit\" does signed integer overflow to\na very negative value.\nIn this situation, the syzkaller script provided by Cristoph triggers the\nCPU soft-lockup warning even with few sockets. It's not an infinite loop,\nbut \"credit\" wasn't probably meant to be minus 2Gb for each new flow.\nCapping \"initial quantum\" to INT_MAX proved to fix the issue.\n\nv2: validation of \"initial quantum\" is done in fq_policy, instead of open\n    coding in fq_change() _ suggested by Jakub Kicinski"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"4b8a05e3801661a0438fcd0cdef181030d966a5a","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"d0b43125ec892aeb1b03e5df5aab595097da225a","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"4fbefeab88c6e79753a25099d455d3d59d2946b4","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"85f24cb2f10b2b0f2882e5786a09b4790bb3a0ad","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"2322462d6f9ad4874f4e3c63df3b5cc00cb1acbd","versionType":"git"},{"version":"afe4fd062416b158a8a8538b23adc1930a9b88dc","status":"affected","lessThan":"7041101ff6c3073fd8f2e99920f535b111c929cb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_fq.c","tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.12","versionType":"semver"},{"version":"5.10.180","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.111","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.28","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.15","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3.2","status":"unaffected","lessThanOrEqual":"6.3.*","versionType":"semver"},{"version":"6.4","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_fq.c","tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json"]}],"references":[{"url":"https://git.kernel.org/stable/c/4b8a05e3801661a0438fcd0cdef181030d966a5a"},{"url":"https://git.kernel.org/stable/c/d0b43125ec892aeb1b03e5df5aab595097da225a"},{"url":"https://git.kernel.org/stable/c/4fbefeab88c6e79753a25099d455d3d59d2946b4"},{"url":"https://git.kernel.org/stable/c/85f24cb2f10b2b0f2882e5786a09b4790bb3a0ad"},{"url":"https://git.kernel.org/stable/c/2322462d6f9ad4874f4e3c63df3b5cc00cb1acbd"},{"url":"https://git.kernel.org/stable/c/7041101ff6c3073fd8f2e99920f535b111c929cb"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:48:45.406Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"5.10.180"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"5.15.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.1.28"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.2.15"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.3.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}