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

net/iucv: fix use after free in iucv_sock_close()

iucv_sever_path() is called from process context and from bh context.
iucv->path is used as indicator whether somebody else is taking care of
severing the path (or it is already removed / never existed).
This needs to be done with atomic compare and swap, otherwise there is a
small window where iucv_sock_close() will try to work with a path that has
already been severed and freed by iucv_callback_connrej() called by
iucv_tasklet_fn().

Example:
[452744.123844] Call Trace:
[452744.123845] ([<0000001e87f03880>] 0x1e87f03880)
[452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138
[452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv]
[452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv]
[452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv]
[452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8
[452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48
[452744.124820] [<00000000d5421642>] __fput+0xba/0x268
[452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0
[452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90
[452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8
[452744.125319] Last Breaking-Event-Address:
[452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138
[452744.125324]
[452744.125325] Kernel panic - not syncing: Fatal exception in interrupt

Note that bh_lock_sock() is not serializing the tasklet context against
process context, because the check for sock_owned_by_user() and
corresponding handling is missing.

Ideas for a future clean-up patch:
A) Correct usage of bh_lock_sock() in tasklet context, as described in
Re-enqueue, if needed. This may require adding return values to the
tasklet functions and thus changes to all users of iucv.

B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.
Published: 2024-08-17
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4008-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-7069-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7069-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-6 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7089-7 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-7090-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7095-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7100-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7100-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7110-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7119-1 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-7123-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7144-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7156-1 Linux kernel (GKE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7194-1 Linux kernel (Azure) vulnerabilities
History

Mon, 03 Nov 2025 22:30:00 +0000

Type Values Removed Values Added
References

Wed, 04 Dec 2024 14:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:rhel_eus:9.4

Wed, 13 Nov 2024 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.2
cpe:/a:redhat:rhel_eus:9.2::nfv
Vendors & Products Redhat rhel Eus

Wed, 13 Nov 2024 02:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Wed, 11 Sep 2024 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 20 Aug 2024 21:30:00 +0000


Mon, 19 Aug 2024 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-416
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Mon, 19 Aug 2024 04:45:00 +0000


Sat, 17 Aug 2024 09:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use after free in iucv_sock_close() iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn(). Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8 [452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48 [452744.124820] [<00000000d5421642>] __fput+0xba/0x268 [452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0 [452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90 [452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8 [452744.125319] Last Breaking-Event-Address: [452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138 [452744.125324] [452744.125325] Kernel panic - not syncing: Fatal exception in interrupt Note that bh_lock_sock() is not serializing the tasklet context against process context, because the check for sock_owned_by_user() and corresponding handling is missing. Ideas for a future clean-up patch: A) Correct usage of bh_lock_sock() in tasklet context, as described in Re-enqueue, if needed. This may require adding return values to the tasklet functions and thus changes to all users of iucv. B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.
Title net/iucv: fix use after free in iucv_sock_close()
References

Subscriptions

Linux Linux Kernel
Redhat Enterprise Linux Rhel Eus
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T20:29:07.496Z

Reserved: 2024-07-30T07:40:12.260Z

Link: CVE-2024-42271

cve-icon Vulnrichment

Updated: 2025-11-03T22:03:07.104Z

cve-icon NVD

Status : Modified

Published: 2024-08-17T09:15:08.307

Modified: 2025-11-03T22:17:52.917

Link: CVE-2024-42271

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-08-17T00:00:00Z

Links: CVE-2024-42271 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses