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.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Ubuntu USN |
USN-7069-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7069-2 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7088-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7088-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7088-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7088-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7088-5 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-5 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-6 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-7 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-7090-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7095-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7100-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7100-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7110-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7119-1 | Linux kernel (IoT) vulnerabilities |
Ubuntu USN |
USN-7123-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7144-1 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-7156-1 | Linux kernel (GKE) vulnerabilities |
Ubuntu USN |
USN-7194-1 | Linux kernel (Azure) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
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
|
Tue, 20 Aug 2024 21:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
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
|
Mon, 19 Aug 2024 04:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
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 |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T22:03:07.104Z
Reserved: 2024-07-30T07:40:12.260Z
Link: CVE-2024-42271
Updated: 2025-11-03T22:03:07.104Z
Status : Modified
Published: 2024-08-17T09:15:08.307
Modified: 2025-11-03T22:17:52.917
Link: CVE-2024-42271
OpenCVE Enrichment
No data.
Debian DLA
Ubuntu USN