Oracle Linux: CVE-2024-42271: ELSA-2024-12782: Unbreakable Enterprise kernel-container security update (IMPORTANT) (Multiple Advisories)

Oracle Linux: CVE-2024-42271: ELSA-2024-12782: Unbreakable Enterprise kernel-container security update (IMPORTANT) (Multiple Advisories)

Severity

5

CVSS

(AV:L/AC:H/Au:S/C:C/I:N/A:C)

Published

08/17/2024

Created

10/18/2024

Added

10/16/2024

Modified

01/23/2025

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.

Solution(s)

• oracle-linux-upgrade-kernel-uek

References

• https://attackerkb.com/topics/cve-2024-42271
• CVE - 2024-42271
• ELSA-2024-12782
• ELSA-2024-12780
• ELSA-2024-12815
• ELSA-2024-12868