{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-42240","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-07-30T07:40:12.253Z","datePublished":"2024-08-07T15:14:27.977Z","dateUpdated":"2025-11-03T22:02:42.210Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T12:57:48.564Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/bhi: Avoid warning in #DB handler due to BHI mitigation\n\nWhen BHI mitigation is enabled, if SYSENTER is invoked with the TF flag set\nthen entry_SYSENTER_compat() uses CLEAR_BRANCH_HISTORY and calls the\nclear_bhb_loop() before the TF flag is cleared. This causes the #DB handler\n(exc_debug_kernel()) to issue a warning because single-step is used outside the\nentry_SYSENTER_compat() function.\n\nTo address this issue, entry_SYSENTER_compat() should use CLEAR_BRANCH_HISTORY\nafter making sure the TF flag is cleared.\n\nThe problem can be reproduced with the following sequence:\n\n  $ cat sysenter_step.c\n  int main()\n  { asm(\"pushf; pop %ax; bts $8,%ax; push %ax; popf; sysenter\"); }\n\n  $ gcc -o sysenter_step sysenter_step.c\n\n  $ ./sysenter_step\n  Segmentation fault (core dumped)\n\nThe program is expected to crash, and the #DB handler will issue a warning.\n\nKernel log:\n\n  WARNING: CPU: 27 PID: 7000 at arch/x86/kernel/traps.c:1009 exc_debug_kernel+0xd2/0x160\n  ...\n  RIP: 0010:exc_debug_kernel+0xd2/0x160\n  ...\n  Call Trace:\n  <#DB>\n   ? show_regs+0x68/0x80\n   ? __warn+0x8c/0x140\n   ? exc_debug_kernel+0xd2/0x160\n   ? report_bug+0x175/0x1a0\n   ? handle_bug+0x44/0x90\n   ? exc_invalid_op+0x1c/0x70\n   ? asm_exc_invalid_op+0x1f/0x30\n   ? exc_debug_kernel+0xd2/0x160\n   exc_debug+0x43/0x50\n   asm_exc_debug+0x1e/0x40\n  RIP: 0010:clear_bhb_loop+0x0/0xb0\n  ...\n  </#DB>\n  <TASK>\n   ? entry_SYSENTER_compat_after_hwframe+0x6e/0x8d\n  </TASK>\n\n  [ bp: Massage commit message. ]"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/entry/entry_64_compat.S"],"versions":[{"version":"bd53ec80f21839cfd4d852a6088279d602d67e5b","lessThan":"db56615e96c439e13783d7715330e824b4fd4b84","status":"affected","versionType":"git"},{"version":"07dbb10f153f483e8249acebdffedf922e2ec2e1","lessThan":"a765679defe1dc1b8fa01928a6ad6361e72a1364","status":"affected","versionType":"git"},{"version":"eb36b0dce2138581bc6b5e39d0273cb4c96ded81","lessThan":"dae3543db8f0cf8ac1a198c3bb4b6e3c24d576cf","status":"affected","versionType":"git"},{"version":"7390db8aea0d64e9deb28b8e1ce716f5020c7ee5","lessThan":"08518d48e5b744620524f0acd7c26c19bda7f513","status":"affected","versionType":"git"},{"version":"7390db8aea0d64e9deb28b8e1ce716f5020c7ee5","lessThan":"ac8b270b61d48fcc61f052097777e3b5e11591e0","status":"affected","versionType":"git"},{"version":"8f51637712e4da5be410a1666f8aee0d86eef898","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/entry/entry_64_compat.S"],"versions":[{"version":"6.9","status":"affected"},{"version":"0","lessThan":"6.9","status":"unaffected","versionType":"semver"},{"version":"5.15.163","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.100","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.41","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.9.10","lessThanOrEqual":"6.9.*","status":"unaffected","versionType":"semver"},{"version":"6.10","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.154","versionEndExcluding":"5.15.163"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.85","versionEndExcluding":"6.1.100"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.26","versionEndExcluding":"6.6.41"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.9.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8.5"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/db56615e96c439e13783d7715330e824b4fd4b84"},{"url":"https://git.kernel.org/stable/c/a765679defe1dc1b8fa01928a6ad6361e72a1364"},{"url":"https://git.kernel.org/stable/c/dae3543db8f0cf8ac1a198c3bb4b6e3c24d576cf"},{"url":"https://git.kernel.org/stable/c/08518d48e5b744620524f0acd7c26c19bda7f513"},{"url":"https://git.kernel.org/stable/c/ac8b270b61d48fcc61f052097777e3b5e11591e0"}],"title":"x86/bhi: Avoid warning in #DB handler due to BHI mitigation","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-42240","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T16:13:51.001454Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-09-11T17:34:31.693Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T22:02:42.210Z"}}]}}