CVE-2024-26885

2024-04-1700:00:00

ubuntu.com

linux kernel

vulnerability resolved

devmap code

overflow check

32-bit arches

arm32

syzbot

crash

update operation

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

7.8

Confidence

High

EPSS

Percentile

5.1%

JSON

In the Linux kernel, the following vulnerability has been resolved: bpf:
Fix DEVMAP_HASH overflow check on 32-bit arches The devmap code allocates a
number hash buckets equal to the next power of two of the max_entries value
provided when creating the map. When rounding up to the next power of two,
the 32-bit variable storing the number of buckets can overflow, and the
code checks for overflow by checking if the truncated 32-bit value is equal
to 0. However, on 32-bit arches the rounding up itself can overflow mid-way
through, because it ends up doing a left-shift of 32 bits on an unsigned
long value. If the size of an unsigned long is four bytes, this is
undefined behaviour, so there is no guarantee that we’ll end up with a nice
and tidy 0-value at the end. Syzbot managed to turn this into a crash on
arm32 by creating a DEVMAP_HASH with max_entries > 0x80000000 and then
trying to update it. Fix this by moving the overflow check to before the
rounding up operation.

OSVersionArchitecturePackageVersionFilename
ubuntu20.04noarchlinux< anyUNKNOWN
ubuntu22.04noarchlinux< 5.15.0-112.122UNKNOWN
ubuntu24.04noarchlinux< 6.8.0-35.35UNKNOWN
ubuntu20.04noarchlinux-aws< anyUNKNOWN
ubuntu22.04noarchlinux-aws< 5.15.0-1063.69UNKNOWN
ubuntu24.04noarchlinux-aws< 6.8.0-1009.9UNKNOWN
ubuntu20.04noarchlinux-aws-5.15< 5.15.0-1063.69~20.04.1UNKNOWN
ubuntu22.04noarchlinux-aws-6.5< anyUNKNOWN
ubuntu20.04noarchlinux-azure< anyUNKNOWN
ubuntu22.04noarchlinux-azure< 5.15.0-1066.75UNKNOWN

OS	Version	Architecture	Package	Version	Filename
ubuntu	20.04	noarch	linux	< any	UNKNOWN
ubuntu	22.04	noarch	linux	< 5.15.0-112.122	UNKNOWN
ubuntu	24.04	noarch	linux	< 6.8.0-35.35	UNKNOWN
ubuntu	20.04	noarch	linux-aws	< any	UNKNOWN
ubuntu	22.04	noarch	linux-aws	< 5.15.0-1063.69	UNKNOWN
ubuntu	24.04	noarch	linux-aws	< 6.8.0-1009.9	UNKNOWN
ubuntu	20.04	noarch	linux-aws-5.15	< 5.15.0-1063.69~20.04.1	UNKNOWN
ubuntu	22.04	noarch	linux-aws-6.5	< any	UNKNOWN
ubuntu	20.04	noarch	linux-azure	< any	UNKNOWN
ubuntu	22.04	noarch	linux-azure	< 5.15.0-1066.75	UNKNOWN