CyberSecBulletin
CVE-2024-26754NVD status: Analyzed

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2024-26754 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 f0ecdfa679189d26aedfe24212d4e69e42c2c861, f8cbd1791900b5d96466eede8e9439a5b9ca4de7, 2e534fd15e5c2ca15821c897352cf0e8a3e30dca 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 0.25% 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 f0ecdfa679189d26aedfe24212d4e69e42c2c861 or f8cbd1791900b5d96466eede8e9439a5b9ca4de7 or 2e534fd15e5c2ca15821c897352cf0e8a3e30dca or a576308800be28f2eaa099e7caad093b97d66e77, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.19.308 or 5.4.270 or 5.10.211 or 5.15.150, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, f0ecdfa679189d26aedfe24212d4e69e42c2c861; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, f8cbd1791900b5d96466eede8e9439a5b9ca4de7; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, 2e534fd15e5c2ca15821c897352cf0e8a3e30dca; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, a576308800be28f2eaa099e7caad093b97d66e77; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, 3963f16cc7643b461271989b712329520374ad2a; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, ba6b8b02a3314e62571a540efa96560888c5f03e; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, 5013bd54d283eda5262c9ae3bcc966d01daf8576; 459aa660eb1d8ce67080da1983bb81d716aa5a69 up to, but not including, 136cfaca22567a03bbb3bf53a43d8cb5748b80ec; and 1 more rangesf0ecdfa679189d26aedfe24212d4e69e42c2c861, f8cbd1791900b5d96466eede8e9439a5b9ca4de7, 2e534fd15e5c2ca15821c897352cf0e8a3e30dca, a576308800be28f2eaa099e7caad093b97d66e77, 3963f16cc7643b461271989b712329520374ad2a, ba6b8b02a3314e62571a540efa96560888c5f03e
LinuxLinux Kernel4.7 up to, but not including, 4.19.308; 4.20 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; 6.84.19.308, 5.4.270, 5.10.211, 5.15.150, 6.1.80, 6.6.19
DebianDebian Linux10.0Not stated

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: gtp: fix use-after-free and null-ptr-deref in gtp_genl_dump_pdp() The gtp_net_ops pernet operations structure for the subsystem must be registered before registering the generic netlink family. Syzkaller hit 'general protection fault in gtp_genl_dump_pdp' bug: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 5826 Comm: gtp Not tainted 6.8.0-rc3-std-def-alt1 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-alt1 04/01/2014 RIP: 0010:gtp_genl_dump_pdp+0x1be/0x800 [gtp] Code: c6 89 c6 e8 64 e9 86 df 58 45 85 f6 0f 85 4e 04 00 00 e8 c5 ee 86 df 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 de 05 00 00 48 8b 44 24 18 4c 8b 30 4c 39 f0 74 RSP: 0018:ffff888014107220 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88800fcda588 R14: 0000000000000001 R15: 0000000000000000 FS: 00007f1be4eb05c0(0000) GS:ffff88806ce80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1be4e766cf CR3: 000000000c33e000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? show_regs+0x90/0xa0 ? die_addr+0x50/0xd0 ? exc_general_protection+0x148/0x220 ? asm_exc_general_protection+0x22/0x30 ? gtp_genl_dump_pdp+0x1be/0x800 [gtp] ? __alloc_skb+0x1dd/0x350 ? __pfx___alloc_skb+0x10/0x10 genl_dumpit+0x11d/0x230 netlink_dump+0x5b9/0xce0 ? lockdep_hardirqs_on_prepare+0x253/0x430 ? __pfx_netlink_dump+0x10/0x10 ? kasan_save_track+0x10/0x40 ? __kasan_kmalloc+0x9b/0xa0 ? genl_start+0x675/0x970 __netlink_dump_start+0x6fc/0x9f0 genl_family_rcv_msg_dumpit+0x1bb/0x2d0 ? __pfx_genl_family_rcv_msg_dumpit+0x10/0x10 ? genl_op_from_small+0x2a/0x440 ? cap_capable+0x1d0/0x240 ? __pfx_genl_start+0x10/0x10 ? __pfx_genl_dumpit+0x10/0x10 ? __pfx_genl_done+0x10/0x10 ? security_capable+0x9d/0xe0

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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