CVE-2024-42271: Linux kernel · net/iucv: fix use after free in iucv_sock_close()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 4.4.0-1137.143 : patch Linux kernel soon.
Data as of 26 Oct 2026, 23:28 UTC
- Patch
- Available – fixed in 4.4.0-1137.143, 4.15.0-1182.197~14.04.1, 4.4.0-260.294~14.04.1 +99
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Aug 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7069-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7069-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7090-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7095-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkeoppkg:deb/ubuntu/linux-gkeop?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2024-42271 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-42271 (opens in a new tab)
- git.kernel.org/linus/f558120cd709682b739207b48cf7479fd9568431 (opens in a new tab)
- git.kernel.org/stable/c/8b424c9e44111c5a76f41c6b741f8d4c4179d876 (opens in a new tab)
- git.kernel.org/stable/c/01437282fd3904810603f3dc98d2cac6b8b6fc84 (opens in a new tab)
- git.kernel.org/stable/c/69620522c48ce8215e5eb55ffbab8cafee8f407d (opens in a new tab)
- git.kernel.org/stable/c/f558120cd709682b739207b48cf7479fd9568431 (opens in a new tab)
- git.kernel.org/stable/c/84f40b46787ecb67c7ad08a5bb1376141fa10c01 (opens in a new tab)
- git.kernel.org/stable/c/37652fbef9809411cea55ea5fa1a170e299efcd0 (opens in a new tab)
- git.kernel.org/stable/c/c65f72eec60a34ace031426e04e9aff8e5f04895 (opens in a new tab)
- git.kernel.org/stable/c/ac758e1f663fe9bc64f6b47212a2aa18697524f5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7069-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7069-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7090-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7088-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-3 (opens in a new tab)