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x86/bhi: Avoid warning in #DB handler due to BHI mitigation (Linux Linux)

CVE-2024-42240
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.22 % · centile 12 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Modified

Rechercher sur…

Description

In the Linux kernel, the following vulnerability has been resolved: x86/bhi: Avoid warning in #DB handler due to BHI mitigation When BHI mitigation is enabled, if SYSENTER is invoked with the TF flag set then entry_SYSENTER_compat() uses CLEAR_BRANCH_HISTORY and calls the clear_bhb_loop() before the TF flag is cleared. This causes the #DB handler (exc_debug_kernel()) to issue a warning because single-step is used outside the entry_SYSENTER_compat() function. To address this issue, entry_SYSENTER_compat() should use CLEAR_BRANCH_HISTORY after making sure the TF flag is cleared. The problem can be reproduced with the following sequence: $ cat sysenter_step.c int main() { asm("pushf; pop %ax; bts $8,%ax; push %ax; popf; sysenter"); } $ gcc -o sysenter_step sysenter_step.c $ ./sysenter_step Segmentation fault (core dumped) The program is expected to crash, and the #DB handler will issue a warning. Kernel log: WARNING: CPU: 27 PID: 7000 at arch/x86/kernel/traps.c:1009 exc_debug_kernel+0xd2/0x160 ... RIP: 0010:exc_debug_kernel+0xd2/0x160 ... Call Trace: <#DB> ? show_regs+0x68/0x80 ? __warn+0x8c/0x140 ? exc_debug_kernel+0xd2/0x160 ? report_bug+0x175/0x1a0 ? handle_bug+0x44/0x90 ? exc_invalid_op+0x1c/0x70 ? asm_exc_invalid_op+0x1f/0x30 ? exc_debug_kernel+0xd2/0x160 exc_debug+0x43/0x50 asm_exc_debug+0x1e/0x40 RIP: 0010:clear_bhb_loop+0x0/0xb0 ... </#DB> <TASK> ? entry_SYSENTER_compat_after_hwframe+0x6e/0x8d </TASK> [ bp: Massage commit message. ]

Faiblesses (CWE)

  • CWE-835 — Boucle dont la condition de sortie est inatteignable (boucle infinie)

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected bd53ec80f21839cfd4d852a6088279d602d67e5b < db56615e96c439e13783d7715330e824b4fd4b84 ; affected 07dbb10f153f483e8249acebdffedf922e2ec2e1 < a765679defe1dc1b8fa01928a6ad6361e72a1364 ; affected eb36b0dce2138581bc6b5e39d0273cb4c96ded81 < dae3543db8f0cf8ac1a198c3bb4b6e3c24d576cf ; affected 7390db8aea0d64e9deb28b8e1ce716f5020c7ee5 < 08518d48e5b744620524f0acd7c26c19bda7f513 ; affected 7390db8aea0d64e9deb28b8e1ce716f5020c7ee5 < ac8b270b61d48fcc61f052097777e3b5e11591e0 ; affected 8f51637712e4da5be410a1666f8aee0d86eef898
Linux · Linuxaffected 6.9 ; unaffected 0 < 6.9 ; unaffected 5.15.163 ≤ 5.15.* ; unaffected 6.1.100 ≤ 6.1.* ; unaffected 6.6.41 ≤ 6.6.* ; unaffected 6.9.10 ≤ 6.9.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD