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

What is CVE-2024-35921?

CVE-2024-35921 is a high-severity use after free vulnerability in Linux kernel, published on 19 May 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: 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)

Weakness: CWE-416

Which versions are affected by CVE-2024-35921?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-35921?

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-2024-35921 being exploited?

There is no known exploitation of CVE-2024-35921 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2024-35921, DEBIAN-CVE-2024-35921, GHSA-qh4w-v3w8-h422, UBUNTU-CVE-2024-35921.