CyberSecBulletin
CVE-2024-26748NVD status: Modified

Linux: Double Free

Published Updated By the CyberSecBulletin desk

CVE-2024-26748 is a high-severity double 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 aad6132ae6e4809e375431f8defd1521985e44e7, 1e204a8e9eb514e22a6567fb340ebb47df3f3a48, 3a2a909942b5335b7ea66366d84261b3ed5f89c8 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 0.24% 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 aad6132ae6e4809e375431f8defd1521985e44e7 or 1e204a8e9eb514e22a6567fb340ebb47df3f3a48 or 3a2a909942b5335b7ea66366d84261b3ed5f89c8 or 9a52b694b066f299d8b9800854a8503457a8b64c, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.270 or 5.10.211 or 5.15.150 or 6.1.80, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, aad6132ae6e4809e375431f8defd1521985e44e7; 7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, 1e204a8e9eb514e22a6567fb340ebb47df3f3a48; 7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, 3a2a909942b5335b7ea66366d84261b3ed5f89c8; 7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, 9a52b694b066f299d8b9800854a8503457a8b64c; 7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, 70e8038813f9d3e72df966748ebbc40efe466019; 7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, 92d20406a3d4ff3e8be667c79209dc9ed31df5b3; 7733f6c32e36ff9d7adadf40001039bf219b1cbe up to, but not including, 5fd9e45f1ebcd57181358af28506e8a661a260b3; 5.4aad6132ae6e4809e375431f8defd1521985e44e7, 1e204a8e9eb514e22a6567fb340ebb47df3f3a48, 3a2a909942b5335b7ea66366d84261b3ed5f89c8, 9a52b694b066f299d8b9800854a8503457a8b64c, 70e8038813f9d3e72df966748ebbc40efe466019, 92d20406a3d4ff3e8be667c79209dc9ed31df5b3
LinuxLinux Kernel5.4 up to, but not including, 5.4.270; 5.5 up to, but not including, 5.10.211; 5.11 up to, but not including, 5.15.150; 5.16 up to, but not including, 6.1.80; 6.2 up to, but not including, 6.6.19; 6.7 up to, but not including, 6.7.7; 6.85.4.270, 5.10.211, 5.15.150, 6.1.80, 6.6.19, 6.7.7

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: usb: cdns3: fix memory double free when handle zero packet 829 if (request->complete) { 830 spin_unlock(&priv_dev->lock); 831 usb_gadget_giveback_request(&priv_ep->endpoint, 832 request); 833 spin_lock(&priv_dev->lock); 834 } 835 836 if (request->buf == priv_dev->zlp_buf) 837 cdns3_gadget_ep_free_request(&priv_ep->endpoint, request); Driver append an additional zero packet request when queue a packet, which length mod max packet size is 0. When transfer complete, run to line 831, usb_gadget_giveback_request() will free this requestion. 836 condition is true, so cdns3_gadget_ep_free_request() free this request again. Log: [ 1920.140696][ T150] BUG: KFENCE: use-after-free read in cdns3_gadget_giveback+0x134/0x2c0 [cdns3] [ 1920.140696][ T150] [ 1920.151837][ T150] Use-after-free read at 0x000000003d1cd10b (in kfence-#36): [ 1920.159082][ T150] cdns3_gadget_giveback+0x134/0x2c0 [cdns3] [ 1920.164988][ T150] cdns3_transfer_completed+0x438/0x5f8 [cdns3] Add check at line 829, skip call usb_gadget_giveback_request() if it is additional zero length packet request. Needn't call usb_gadget_giveback_request() because it is allocated in this driver.

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

The underlying weakness: Double Free

The product calls free() twice on the same memory address.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
  • Use a static analysis tool to find double free instances.

More Double Free vulnerabilities (CWE-415)

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 Double Free vulnerabilities

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