CVE-2022-50080: tee: add overflow check in register_shm_helper()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-18 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: tee: add overflow check in register_shm_helper() With special lengths supplied by user space, register_shm_helper() has an integer overflow when calculating the number of pages covered by a supplied user space memory region. This causes internal_get_user_pages_fast() a helper function of pin_user_pages_fast() to do a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 Modules linked in: CPU: 1 PID: 173 Comm: optee_example_a Not tainted 5.19.0 #11 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pc : internal_get_user_pages_fast+0x474/0xa80 Call trace: internal_get_user_pages_fast+0x474/0xa80 pin_user_pages_fast+0x24/0x4c register_shm_helper+0x194/0x330 tee_shm_register_user_buf+0x78/0x120 tee_ioctl+0xd0/0x11a0 __arm64_sys_ioctl+0xa8/0xec invoke_syscall+0x48/0x114 Fix this by adding an an explicit call to access_ok() in tee_shm_register_user_buf() to catch an invalid user space address early.

Affected products

Linux kernel: from 4.16 before 4.19.256; from 4.20 before 5.4.211; from 5.5 before 5.10.137; from 5.11 before 5.15.62; from 5.16 before 5.18.19; from 5.19 before 5.19.3 — fixed in 4.19.256, 5.10.137, 5.15.62, 5.18.19, 5.19.3, 5.4.211

How to fix

Upgrade to a fixed version: Linux kernel 4.19.256, 5.10.137, 5.15.62, 5.18.19. Check the vendor advisory for mitigations.

References

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