CVE-2025-38305

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Source
https://nvd.nist.gov/vuln/detail/CVE-2025-38305
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-38305.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-38305
Downstream
Related
Published
2025-07-10T08:15:29Z
Modified
2025-08-12T21:51:20.542442Z
Summary
[none]
Details

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

ptp: remove ptp->nvclocks check logic in ptpvclockinuse()

There is no disagreement that we should check both ptp->isvirtualclock and ptp->n_vclocks to check if the ptp virtual clock is in use.

However, when we acquire ptp->nvclocksmux to read ptp->nvclocks in ptpvclockinuse(), we observe a recursive lock in the call trace starting from nvclocksstore().

============================================ WARNING: possible recursive locking detected

6.15.0-rc6 #1 Not tainted

syz.0.1540/13807 is trying to acquire lock: ffff888035a24868 (&ptp->nvclocksmux){+.+.}-{4:4}, at: ptpvclockinuse drivers/ptp/ptpprivate.h:103 [inline] ffff888035a24868 (&ptp->nvclocksmux){+.+.}-{4:4}, at: ptpclockunregister+0x21/0x250 drivers/ptp/ptp_clock.c:415

but task is already holding lock: ffff888030704868 (&ptp->nvclocksmux){+.+.}-{4:4}, at: nvclocksstore+0xf1/0x6d0 drivers/ptp/ptp_sysfs.c:215

other info that might help us debug this: Possible unsafe locking scenario:

   CPU0
   ----

lock(&ptp->nvclocksmux); lock(&ptp->nvclocksmux);

* DEADLOCK *

....

The best way to solve this is to remove the logic that checks ptp->nvclocks in ptpvclockinuse().

The reason why this is appropriate is that any path that uses ptp->nvclocks must unconditionally check if ptp->nvclocks is greater than 0 before unregistering vclocks, and all functions are already written this way. And in the function that uses ptp->nvclocks, we already get ptp->nvclocks_mux before unregistering vclocks.

Therefore, we need to remove the redundant check for ptp->nvclocks in ptpvclockinuse() to prevent recursive locking.

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
6.1.147-1

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
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.1.135-1
6.1.137-1
6.1.139-1
6.1.140-1

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
6.12.35-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:14 / 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
6.12.35-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}