CVE-2024-42271

/// Technical 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/0xe

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References