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

2024-04-1710:27:33

Linux

github.com

linux

kernel

pvrusb2

vulnerability

uaf

pvr2_context_set_notify

fix

media

usb

disconnect_flag

task a

task b

AI Score

6.8

Confidence

Low

SSVC

Exploitation

none

Automatable

Technical Impact

total

JSON

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.

ADP Affected

[
  {
    "cpes": [
      "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*"
    ],
    "vendor": "linux",
    "product": "linux_kernel",
    "versions": [
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "ed8000e1e8e9",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "d29ed08964ce",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "ab896d93fd6a",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "eb6e9dce979c",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "3a1ec89708d2",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "versionType": "custom",
        "lessThanOrEqual": "8e60b99f6b7c"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "40cd818fae87",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "eaa410e05bdf",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "e5be15c63804",
        "lessThan": "0a0b79ea55de",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "2.6.26"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.26",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "4.19.311",
        "versionType": "custom",
        "lessThanOrEqual": "4.20"
      },
      {
        "status": "unaffected",
        "version": "5.4.273",
        "versionType": "custom",
        "lessThanOrEqual": "5.5"
      },
      {
        "status": "unaffected",
        "version": "5.10.214",
        "versionType": "custom",
        "lessThanOrEqual": "5.11"
      },
      {
        "status": "unaffected",
        "version": "5.15.153",
        "versionType": "custom",
        "lessThanOrEqual": "5.16"
      },
      {
        "status": "unaffected",
        "version": "6.183",
        "versionType": "custom",
        "lessThanOrEqual": "6.2"
      },
      {
        "status": "unaffected",
        "version": "6.6.23",
        "versionType": "custom",
        "lessThanOrEqual": "6.7"
      },
      {
        "status": "unaffected",
        "version": "6.7.11",
        "versionType": "custom",
        "lessThanOrEqual": "6.8"
      },
      {
        "status": "unaffected",
        "version": "6.8.2",
        "versionType": "custom",
        "lessThanOrEqual": "6.9"
      },
      {
        "status": "unaffected",
        "version": "6.9",
        "versionType": "custom",
        "lessThanOrEqual": "*"
      }
    ],
    "defaultStatus": "unknown"
  }
]