kernel: pty layer race condition on tty ldisc shutdown.
Published May 2, 2016
4.7
MEDIUMCVSS 3.0
EPSS 0.33%
Description
Race condition in the ldsem_cmpxchg function in drivers/tty/tty_ldsem.c in the Linux kernel before 3.13-rc4-next-20131218 allows local users to cause a denial of service (ldsem_down_read and ldsem_down_write deadlock) by establishing a new tty thread during shutdown of a previous tty thread.
Affected products
No data.
Configuration 1
- ≤ 3.13.3
Configuration 2
- 7.1
- 7.1_s390x
- 7.1_ppc64
- 7.1_ppc64le
- 7.1
No data.
Red Hat Enterprise Linux 7
kernel-0:3.10.0-327.el7
Fixed · RHSA-2015:2152
Red Hat Enterprise Linux 7
kernel-rt-0:3.10.0-327.rt56.204.el7
Fixed · RHSA-2015:2411
Red Hat Enterprise Linux 7.1 Extended Update Support
kernel-0:3.10.0-229.38.1.ael7b
Fixed · RHSA-2016:1395
Red Hat Enterprise Linux 4
kernel
Not affected
Red Hat Enterprise Linux 5
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-aarch64
Not affected
Red Hat Enterprise MRG 2
realtime-kernel
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | kernel-0:3.10.0-327.el7 | Fixed | RHSA-2015:2152 |
| Red Hat Enterprise Linux 7 | kernel-rt-0:3.10.0-327.rt56.204.el7 | Fixed | RHSA-2015:2411 |
| Red Hat Enterprise Linux 7.1 Extended Update Support | kernel-0:3.10.0-229.38.1.ael7b | Fixed | RHSA-2016:1395 |
| Red Hat Enterprise Linux 4 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 5 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-aarch64 | Not affected | n/a |
| Red Hat Enterprise MRG 2 | realtime-kernel | Affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 5, 6. This issue affects the Linux kernel packages kernel as shipped with Red Hat Enterprise Linux 7 and Red Hat Enterprise MRG 2.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
AV:L/AC:M/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.33% (0.00326) | 23.30th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.33% (0.00326) | 24.11th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.04% (0.00041) | 9.70th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.10% (0.00103) | 43.55th | v3 (v2023.03.01) |
| Dec 19, 2023 | 0.10% (0.00103) | 41.54th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.09% (0.00094) | 38.38th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.18% (0.01183) | 61.76th | v2 (v2022.01.01) |
| Oct 19, 2022 | 1.18% (0.01183) | 60.79th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.18% (0.01183) | 58.77th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.18% (0.01183) | 35.15th | v2 (v2022.01.01) |
References (11)
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cf872776fc84128bb779ce2b83a37c884c3203ae x_refsource_CONFIRMVendor Advisory
- http://www.openwall.com/lists/oss-security/2015/05/26/1 mailing-listx_refsource_MLIST
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html x_refsource_CONFIRM
- http://www.securityfocus.com/bid/74820 vdb-entryx_refsource_BID
- https://access.redhat.com/errata/RHSA-2016:1395 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2015-4170 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1218879 x_refsource_CONFIRMIssue TrackingVDB Entry
- https://github.com/torvalds/linux/commit/cf872776fc84128bb779ce2b83a37c884c3203ae x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2015-4170
- https://www.cve.org/CVERecord?id=CVE-2015-4170
- https://www.kernel.org/pub/linux/kernel/next/patch-v3.13-rc4-next-20131218.xz x_refsource_CONFIRMPatch
| Link | Providers | Tags |
|---|---|---|
| http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cf872776fc84128bb779ce2b83a37c884c3203ae | x_refsource_CONFIRMVendor Advisory | |
| http://www.openwall.com/lists/oss-security/2015/05/26/1 | mailing-listx_refsource_MLIST | |
| http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html | x_refsource_CONFIRM | |
| http://www.securityfocus.com/bid/74820 | vdb-entryx_refsource_BID | |
| https://access.redhat.com/errata/RHSA-2016:1395 | vendor-advisoryx_refsource_REDHATThird Party Advisory | |
| https://access.redhat.com/security/cve/CVE-2015-4170 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1218879 | x_refsource_CONFIRMIssue TrackingVDB Entry | |
| https://github.com/torvalds/linux/commit/cf872776fc84128bb779ce2b83a37c884c3203ae | x_refsource_CONFIRM | |
| https://nvd.nist.gov/vuln/detail/CVE-2015-4170 | ||
| https://www.cve.org/CVERecord?id=CVE-2015-4170 | ||
| https://www.kernel.org/pub/linux/kernel/next/patch-v3.13-rc4-next-20131218.xz | x_refsource_CONFIRMPatch |
Change history (0)
No recorded changes yet.