Description

In the Linux kernel, the following vulnerability has been resolved: mtdchar: fix integer overflow in read/write ioctls The "req.start" and "req.len" variables are u64 values that come from the user at the start of the function. We mask away the high 32 bits of "req.len" so that's capped at U32_MAX but the "req.start" variable can go up to U64_MAX which means that the addition can still integer overflow. Use check_add_overflow() to fix this bug.

References 5

• git.kernel.org https://git.kernel.org/stable/c/37944f4f8199cd153fef74e95ca268020162f212
• git.kernel.org https://git.kernel.org/stable/c/457376c6fbf0c69326a9bf1f72416225f681192b
• git.kernel.org https://git.kernel.org/stable/c/e4185bed738da755b191aa3f2e16e8b48450e1b8
• git.kernel.org https://git.kernel.org/stable/c/eb9361484814fb12f3b7544b33835ea67d7a6a97
• git.kernel.org https://git.kernel.org/stable/c/f37efdd97fd1ec3e0d0f1eec279c8279e28f981e

Remediation