- Description
- In 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.
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD status
- Analyzed
- Products
- linux_kernel, debian_linux
CVSS 3.1
- Type
- Primary
- Base score
- 5.5
- Impact score
- 3.6
- Exploitability score
- 1.8
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Severity
- MEDIUM
- Hype score
- Not currently trending
[
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "7F369340-2B76-438A-A8D2-7A0F994DC4AC",
"versionEndExcluding": "5.15.186",
"versionStartIncluding": "5.14.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "459B4E94-FE0E-434D-B782-95E3A5FFC6B1",
"versionEndExcluding": "6.1.142",
"versionStartIncluding": "5.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "304E3F01-7D7A-4908-994E-7F95C5C00B06",
"versionEndExcluding": "6.6.94",
"versionStartIncluding": "6.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "4FFA54AA-CDFE-4591-BD07-72813D0948F4",
"versionEndExcluding": "6.12.34",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "0541C761-BD5E-4C1A-8432-83B375D7EB92",
"versionEndExcluding": "6.15.3",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:*",
"matchCriteriaId": "6A05198E-F8FA-4517-8D0E-8C95066AED38",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:*",
"matchCriteriaId": "23B9E5C6-FAB5-4A02-9E39-27C8787B0991",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:*",
"matchCriteriaId": "D185CF67-7E4A-4154-93DB-CE379C67DB56",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:*",
"matchCriteriaId": "D1DA0AF6-02F4-47C7-A318-8C006ED0C665",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:*",
"matchCriteriaId": "49DD30B1-8C99-4C38-A66B-CAB3827BEE8A",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc6:*:*:*:*:*:*",
"matchCriteriaId": "15013998-4AF0-4CDC-AB13-829ECD8A8E66",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc7:*:*:*:*:*:*",
"matchCriteriaId": "376A25CF-C05B-48F1-99B1-8FB0314A8E06",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*",
"matchCriteriaId": "6D4894DB-CCFE-4602-B1BF-3960B2E19A01",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
},
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
"matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
]