CVE-2024-35827 io_uring/net: fix overflow check in io_recvmsg_mshot_prep()

What is CVE-2024-35827?

CVE-2024-35827 is a high-severity vulnerability in Linux kernel, published on 17 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:

io_uring/net: fix overflow check in io_recvmsg_mshot_prep()

The "controllen" variable is type size_t (unsigned long). Casting it to int could lead to an integer underflow.

The check_add_overflow() function considers the type of the destination which is type int. If we add two positive values and the result cannot fit in an integer then that's counted as an overflow.

However, if we cast "controllen" to an int and it turns negative, then negative values *can* fit into an int type so there is no overflow.

Good: 100 + (unsigned long)-4 = 96 <-- overflow Bad: 100 + (int)-4 = 96 <-- no overflow

I deleted the cast of the sizeof() as well. That's not a bug but the cast is unnecessary.

Weakness: CWE-190

Which versions are affected by CVE-2024-35827?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-35827?

Apply the vendor's patch.

Is CVE-2024-35827 being exploited?

There is no known exploitation of CVE-2024-35827 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-2024-35827, DEBIAN-CVE-2024-35827, GHSA-7hqf-f5qc-8535, UBUNTU-CVE-2024-35827.