CVE-2024-35921 media: mediatek: vcodec: Fix oops when HEVC init fails

2024-05-1910:10:33

Linux

github.com

linux kernel

vulnerability

media

mediatek

vcodec

hevc

decoder

instance pointer

use after free

hardware name

acer tomato

stateless

initialization

deinit function.

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.6%

JSON

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

media: mediatek: vcodec: Fix oops when HEVC init fails

The stateless HEVC decoder saves the instance pointer in the context
regardless if the initialization worked or not. This caused a use after
free, when the pointer is freed in case of a failure in the deinit
function.
Only store the instance pointer when the initialization was successful,
to solve this issue.

Hardware name: Acer Tomato (rev3 - 4) board (DT)
pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=–)
pc : vcodec_vpu_send_msg+0x4c/0x190 [mtk_vcodec_dec]
lr : vcodec_send_ap_ipi+0x78/0x170 [mtk_vcodec_dec]
sp : ffff80008750bc20
x29: ffff80008750bc20 x28: ffff1299f6d70000 x27: 0000000000000000
x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
x23: ffff80008750bc98 x22: 000000000000a003 x21: ffffd45c4cfae000
x20: 0000000000000010 x19: ffff1299fd668310 x18: 000000000000001a
x17: 000000040044ffff x16: ffffd45cb15dc648 x15: 0000000000000000
x14: ffff1299c08da1c0 x13: ffffd45cb1f87a10 x12: ffffd45cb2f5fe80
x11: 0000000000000001 x10: 0000000000001b30 x9 : ffffd45c4d12b488
x8 : 1fffe25339380d81 x7 : 0000000000000001 x6 : ffff1299c9c06c00
x5 : 0000000000000132 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000010 x1 : ffff80008750bc98 x0 : 0000000000000000
Call trace:
vcodec_vpu_send_msg+0x4c/0x190 [mtk_vcodec_dec]
vcodec_send_ap_ipi+0x78/0x170 [mtk_vcodec_dec]
vpu_dec_deinit+0x1c/0x30 [mtk_vcodec_dec]
vdec_hevc_slice_deinit+0x30/0x98 [mtk_vcodec_dec]
vdec_if_deinit+0x38/0x68 [mtk_vcodec_dec]
mtk_vcodec_dec_release+0x20/0x40 [mtk_vcodec_dec]
fops_vcodec_release+0x64/0x118 [mtk_vcodec_dec]
v4l2_release+0x7c/0x100
__fput+0x80/0x2d8
__fput_sync+0x58/0x70
__arm64_sys_close+0x40/0x90
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0x48/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x38/0xd8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x1a8/0x1b0
Code: d503201f f9401660 b900127f b900227f (f9400400)

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_hevc_req_multi_if.c"
    ],
    "versions": [
      {
        "version": "2674486aac7d",
        "lessThan": "ec25fc3c2c1e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "2674486aac7d",
        "lessThan": "521ce0ea7418",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "2674486aac7d",
        "lessThan": "97c75ee5de06",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_hevc_req_multi_if.c"
    ],
    "versions": [
      {
        "version": "6.5",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.5",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.27",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.6",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]