CVE-2021-4439

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Source
https://nvd.nist.gov/vuln/detail/CVE-2021-4439
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-4439.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2021-4439
Related
Published
2024-06-20T12:15:10Z
Modified
2024-09-18T17:45:20.925448Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

isdn: cpai: check ctr->cnr to avoid array index out of bound

The cmtpaddconnection() would add a cmtp session to a controller and run a kernel thread to process cmtp.

__module_get(THIS_MODULE);
session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d",
                            session->num);

During this process, the kernel thread would call detachcapictr() to detach a register controller. if the controller was not attached yet, detachcapictr() would trigger an array-index-out-bounds bug.

[ 46.866069][ T6479] UBSAN: array-index-out-of-bounds in drivers/isdn/capi/kcapi.c:483:21 [ 46.867196][ T6479] index -1 is out of range for type 'capictr *[32]' [ 46.867982][ T6479] CPU: 1 PID: 6479 Comm: kcmtpdctr0 Not tainted 5.15.0-rc2+ #8 [ 46.869002][ T6479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 46.870107][ T6479] Call Trace: [ 46.870473][ T6479] dumpstacklvl+0x57/0x7d [ 46.870974][ T6479] ubsanepilogue+0x5/0x40 [ 46.871458][ T6479] _ubsanhandleoutofbounds.cold+0x43/0x48 [ 46.872135][ T6479] detachcapictr+0x64/0xc0 [ 46.872639][ T6479] cmtpsession+0x5c8/0x5d0 [ 46.873131][ T6479] ? _initwaitqueuehead+0x60/0x60 [ 46.873712][ T6479] ? cmtpaddmsgpart+0x120/0x120 [ 46.874256][ T6479] kthread+0x147/0x170 [ 46.874709][ T6479] ? setkthreadstruct+0x40/0x40 [ 46.875248][ T6479] retfrom_fork+0x1f/0x30 [ 46.875773][ T6479]

References

Affected packages

Debian:11 / 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
5.10.84-1

Affected versions

5.*

5.10.46-4
5.10.46-5
5.10.70-1~bpo10+1
5.10.70-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

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
5.14.16-1

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
5.14.16-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}