CVE-2024-42240

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Source
https://nvd.nist.gov/vuln/detail/CVE-2024-42240
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-42240.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2024-42240
Related
Published
2024-08-07T16:15:46Z
Modified
2024-09-18T03:23:10.661749Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

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 entrySYSENTERcompat() uses CLEARBRANCHHISTORY and calls the clearbhbloop() before the TF flag is cleared. This causes the #DB handler (excdebugkernel()) to issue a warning because single-step is used outside the entrySYSENTERcompat() function.

To address this issue, entrySYSENTERcompat() should use CLEARBRANCHHISTORY 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 sysenterstep sysenterstep.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 excdebugkernel+0xd2/0x160 ... RIP: 0010:excdebugkernel+0xd2/0x160 ... Call Trace: <#DB> ? showregs+0x68/0x80 ? _warn+0x8c/0x140 ? excdebugkernel+0xd2/0x160 ? reportbug+0x175/0x1a0 ? handlebug+0x44/0x90 ? excinvalidop+0x1c/0x70 ? asmexcinvalidop+0x1f/0x30 ? excdebugkernel+0xd2/0x160 excdebug+0x43/0x50 asmexcdebug+0x1e/0x40 RIP: 0010:clearbhbloop+0x0/0xb0 ... </#DB> <TASK> ? entrySYSENTERcompatafterhwframe+0x6e/0x8d </TASK>

[ bp: Massage commit message. ]

References

Affected packages

Debian:12 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.1.106-1

Affected versions

6.*

6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.9.10-1

Affected versions

6.*

6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.3.1-1~exp1
6.3.2-1~exp1
6.3.4-1~exp1
6.3.5-1~exp1
6.3.7-1~bpo12+1
6.3.7-1
6.3.11-1
6.4~rc6-1~exp1
6.4~rc7-1~exp1
6.4.1-1~exp1
6.4.4-1~bpo12+1
6.4.4-1
6.4.4-2
6.4.4-3~bpo12+1
6.4.4-3
6.4.11-1
6.4.13-1
6.5~rc4-1~exp1
6.5~rc6-1~exp1
6.5~rc7-1~exp1
6.5.1-1~exp1
6.5.3-1~bpo12+1
6.5.3-1
6.5.6-1
6.5.8-1
6.5.10-1~bpo12+1
6.5.10-1
6.5.13-1
6.6.3-1~exp1
6.6.4-1~exp1
6.6.7-1~exp1
6.6.8-1
6.6.9-1
6.6.11-1
6.6.13-1~bpo12+1
6.6.13-1
6.6.15-1
6.6.15-2
6.7-1~exp1
6.7.1-1~exp1
6.7.4-1~exp1
6.7.7-1
6.7.9-1
6.7.9-2
6.7.12-1~bpo12+1
6.7.12-1
6.8.9-1
6.8.11-1
6.8.12-1~bpo12+1
6.8.12-1
6.9.2-1~exp1
6.9.7-1~bpo12+1
6.9.7-1
6.9.8-1
6.9.9-1
6.9.10-1~bpo12+1

Ecosystem specific

{
    "urgency": "not yet assigned"
}