n the Linux kernel, the following vulnerability has been resolved: ptp: remove ptp->n_vclocks check logic in ptp_vclock_in_use() There is no disagreement that we should check both ptp->is_virtual_clock and ptp->n_vclocks to check if the ptp virtual clock is in use. However, when we acquire ptp->n_vclocks_mux to read ptp->n_vclocks in ptp_vclock_in_use(), we observe a recursive lock in the call trace starting from n_vclocks_store(). ============================================ WARNING: possible recursive locking detected 6.15.0-rc6 #1 Not tainted -------------------------------------------- syz.0.1540/13807 is trying to acquire lock: ffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_vclock_in_use drivers/ptp/ptp_private.h:103 [inline] ffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_clock_unregister+0x21/0x250 drivers/ptp/ptp_clock.c:415 but task is already holding lock: ffff888030704868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: n_vclocks_store+0xf1/0x6d0 drivers/ptp/ptp_sysfs.c:215 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ptp->n_vclocks_mux); lock(&ptp->n_vclocks_mux); *** DEADLOCK *** .... ============================================ The best way to solve this is to remove the logic that checks ptp->n_vclocks in ptp_vclock_in_use(). The reason why this is appropriate is that any path that uses ptp->n_vclocks must unconditionally check if ptp->n_vclocks is greater than 0 before unregistering vclocks, and all functions are already written this way. And in the function that uses ptp->n_vclocks, we already get ptp->n_vclocks_mux before unregistering vclocks. Therefore, we need to remove the redundant check for ptp->n_vclocks in ptp_vclock_in_use() to prevent recursive locking.
Configuration 1 (hide)
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Configuration 2 (hide)
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19 Dec 2025, 17:58
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/259119595227fd20f6aa29d85abe086b6fdd9eb1 - Patch | |
| References | () https://git.kernel.org/stable/c/5d217e7031a5c06d366580fc6ddbf43527b780d4 - Patch | |
| References | () https://git.kernel.org/stable/c/87f7ce260a3c838b49e1dc1ceedf1006795157a2 - Patch | |
| References | () https://git.kernel.org/stable/c/b1b73c452331451020be3bf4b014901015ae6663 - Patch | |
| References | () https://git.kernel.org/stable/c/b93e6fef4eda48e17d9c642b9abad98a066fd4a3 - Patch | |
| References | () https://git.kernel.org/stable/c/ef8fc007c28a30a4c0d90bf755e0f343d99bb392 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory | |
| CWE | NVD-CWE-noinfo | |
| First Time |
Linux linux Kernel
Debian Linux Debian debian Linux |
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| CPE | cpe:2.3:o:linux:linux_kernel:5.14:rc7:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc6:*:*:*:*:*:* |
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| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
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| References |
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10 Jul 2025, 13:17
| Type | Values Removed | Values Added |
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| Summary |
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10 Jul 2025, 08:15
| Type | Values Removed | Values Added |
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| New CVE |
Published : 2025-07-10 08:15
Updated : 2025-12-19 17:58
NVD link : CVE-2025-38305
Mitre link : CVE-2025-38305
CVE.ORG link : CVE-2025-38305
JSON object : View