CVE-2024-26875 media: pvrusb2: fix uaf in pvr2_context_set_notify

Medium 6.4 Published 17 Apr 2024 Updated 15 Oct 2026

A use-after-free vulnerability in the Linux kernel's pvrusb2 driver allows attackers to cause a denial of service or potentially execute code via race conditions during device disconnection.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2024-26875?

CVE-2024-26875 is a medium-severity use after free vulnerability in Linux kernel, published on 17 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

media: pvrusb2: fix uaf in pvr2_context_set_notify

[Syzbot reported] BUG: KASAN: slab-use-after-free in pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35 Read of size 4 at addr ffff888113aeb0d8 by task kworker/1:1/26

CPU: 1 PID: 26 Comm: kworker/1:1 Not tainted 6.8.0-rc1-syzkaller-00046-gf1a27f081c1f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc4/0x620 mm/kasan/report.c:488 kasan_report+0xda/0x110 mm/kasan/report.c:601 pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35 pvr2_context_notify drivers/media/usb/pvrusb2/pvrusb2-context.c:95 [inline] pvr2_context_disconnect+0x94/0xb0 drivers/media/usb/pvrusb2/pvrusb2-context.c:272

Freed by task 906: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x106/0x1b0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x105/0x340 mm/slub.c:4409 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:137 [inline] pvr2_context_thread_func+0x69d/0x960 drivers/media/usb/pvrusb2/pvrusb2-context.c:158

[Analyze] Task A set disconnect_flag = !0, which resulted in Task B's condition being met and releasing mp, leading to this issue.

[Fix] Place the disconnect_flag assignment operation after all code in pvr2_context_disconnect() to avoid this issue.

Weakness: CWE-416

Which versions are affected by CVE-2024-26875?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-26875?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2024-26875 being exploited?

There is no known exploitation of CVE-2024-26875 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as AZL-47666, AZL-47676, BELL-CVE-2024-26875, DEBIAN-CVE-2024-26875, GHSA-hq4g-8jp3-v42r, UBUNTU-CVE-2024-26875.