CVE-2022-49993

Published Jun 18, 2025

Last updated 5 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: loop: Check for overflow while configuring loop The userspace can configure a loop using an ioctl call, wherein a configuration of type loop_config is passed (see lo_ioctl()'s case on line 1550 of drivers/block/loop.c). This proceeds to call loop_configure() which in turn calls loop_set_status_from_info() (see line 1050 of loop.c), passing &config->info which is of type loop_info64*. This function then sets the appropriate values, like the offset. loop_device has lo_offset of type loff_t (see line 52 of loop.c), which is typdef-chained to long long, whereas loop_info64 has lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h). The function directly copies offset from info to the device as follows (See line 980 of loop.c): lo->lo_offset = info->lo_offset; This results in an overflow, which triggers a warning in iomap_iter() due to a call to iomap_iter_done() which has: WARN_ON_ONCE(iter->iomap.offset > iter->pos); Thus, check for negative value during loop_set_status_from_info(). Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations