CyberSecBulletin
CVE-2024-46798NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2024-46798 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 993b60c7f93fa1d8ff296b58f646a867e945ae89, 8ca21e7a27c66b95a4b215edc8e45e5d66679f9f, 3033ed903b4f28b5e1ab66042084fbc2c48f8624 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 993b60c7f93fa1d8ff296b58f646a867e945ae89 or 8ca21e7a27c66b95a4b215edc8e45e5d66679f9f or 3033ed903b4f28b5e1ab66042084fbc2c48f8624 or fe5046ca91d631ec432eee3bdb1f1c49b09c8b5e, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.284 or 5.10.226 or 5.15.167 or 6.1.110, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, 993b60c7f93fa1d8ff296b58f646a867e945ae89; a72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, 8ca21e7a27c66b95a4b215edc8e45e5d66679f9f; a72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, 3033ed903b4f28b5e1ab66042084fbc2c48f8624; a72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, fe5046ca91d631ec432eee3bdb1f1c49b09c8b5e; a72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, 5d13afd021eb43868fe03cef6da34ad08831ad6d; a72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, 6a14fad8be178df6c4589667efec1789a3307b4e; a72706ed8208ac3f72d1c3ebbc6509e368b0dcb0 up to, but not including, b4a90b543d9f62d3ac34ec1ab97fc5334b048565; 5.4993b60c7f93fa1d8ff296b58f646a867e945ae89, 8ca21e7a27c66b95a4b215edc8e45e5d66679f9f, 3033ed903b4f28b5e1ab66042084fbc2c48f8624, fe5046ca91d631ec432eee3bdb1f1c49b09c8b5e, 5d13afd021eb43868fe03cef6da34ad08831ad6d, 6a14fad8be178df6c4589667efec1789a3307b4e
LinuxLinux Kernel5.4 up to, but not including, 5.4.284; 5.5 up to, but not including, 5.10.226; 5.11 up to, but not including, 5.15.167; 5.16 up to, but not including, 6.1.110; 6.2 up to, but not including, 6.6.51; 6.7 up to, but not including, 6.10.10; 6.115.4.284, 5.10.226, 5.15.167, 6.1.110, 6.6.51, 6.10.10

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: ASoC: dapm: Fix UAF for snd_soc_pcm_runtime object When using kernel with the following extra config, - CONFIG_KASAN=y - CONFIG_KASAN_GENERIC=y - CONFIG_KASAN_INLINE=y - CONFIG_KASAN_VMALLOC=y - CONFIG_FRAME_WARN=4096 kernel detects that snd_pcm_suspend_all() access a freed 'snd_soc_pcm_runtime' object when the system is suspended, which leads to a use-after-free bug: [ 52.047746] BUG: KASAN: use-after-free in snd_pcm_suspend_all+0x1a8/0x270 [ 52.047765] Read of size 1 at addr ffff0000b9434d50 by task systemd-sleep/2330 [ 52.047785] Call trace: [ 52.047787] dump_backtrace+0x0/0x3c0 [ 52.047794] show_stack+0x34/0x50 [ 52.047797] dump_stack_lvl+0x68/0x8c [ 52.047802] print_address_description.constprop.0+0x74/0x2c0 [ 52.047809] kasan_report+0x210/0x230 [ 52.047815] __asan_report_load1_noabort+0x3c/0x50 [ 52.047820] snd_pcm_suspend_all+0x1a8/0x270 [ 52.047824] snd_soc_suspend+0x19c/0x4e0 The snd_pcm_sync_stop() has a NULL check on 'substream->runtime' before making any access. So we need to always set 'substream->runtime' to NULL everytime we kfree() it.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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