Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2024-42136

Disclosure Date: July 30, 2024 •
CVE-2024-42136 CVSS v3 Base Score: 7.8
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

cdrom: rearrange last_media_change check to avoid unintentional overflow

When running syzkaller with the newly reintroduced signed integer wrap
sanitizer we encounter this splat:

[ 366.015950] UBSAN: signed-integer-overflow in ../drivers/cdrom/cdrom.c:2361:33
[ 366.021089] -9223372036854775808 – 346321 cannot be represented in type ‘__s64’ (aka ‘long long’)
[ 366.025894] program syz-executor.4 is using a deprecated SCSI ioctl, please convert it to SG_IO
[ 366.027502] CPU: 5 PID: 28472 Comm: syz-executor.7 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1
[ 366.027512] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 366.027518] Call Trace:
[ 366.027523] <TASK>
[ 366.027533] dump_stack_lvl+0x93/0xd0
[ 366.027899] handle_overflow+0x171/0x1b0
[ 366.038787] ata1.00: invalid multi_count 32 ignored
[ 366.043924] cdrom_ioctl+0x2c3f/0x2d10
[ 366.063932] ? __pm_runtime_resume+0xe6/0x130
[ 366.071923] sr_block_ioctl+0x15d/0x1d0
[ 366.074624] ? __pfx_sr_block_ioctl+0x10/0x10
[ 366.077642] blkdev_ioctl+0x419/0x500
[ 366.080231] ? __pfx_blkdev_ioctl+0x10/0x10
…

Historically, the signed integer overflow sanitizer did not work in the
kernel due to its interaction with -fwrapv but this has since been
changed [1] in the newest version of Clang. It was re-enabled in the
kernel with Commit 557f8c582a9ba8ab (“ubsan: Reintroduce signed overflow
sanitizer”).

Let’s rearrange the check to not perform any arithmetic, thus not
tripping the sanitizer.

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CVSS V3 Severity and Metrics
Base Score:
7.8 High
Impact Score:
5.9
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux 0c97527e9160
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • linux

Products

  • linux kernel
Technical Analysis