CVE Vulnerabilities

CVE-2024-26591

NULL Pointer Dereference

Published: Feb 22, 2024 | Modified: Mar 18, 2024
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

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

bpf: Fix re-attachment branch in bpf_tracing_prog_attach

The following case can cause a crash due to missing attach_btf:

  1. load rawtp program
  2. load fentry program with rawtp as target_fd
  3. create tracing link for fentry program with target_fd = 0
  4. repeat 3

In the end we have:

  • prog->aux->dst_trampoline == NULL

  • tgt_prog == NULL (because we did not provide target_fd to link_create)

  • prog->aux->attach_btf == NULL (the program was loaded with attach_prog_fd=X)

  • the program was loaded for tgt_prog but we have no way to find out which one

    BUG: kernel NULL pointer dereference, address: 0000000000000058 Call Trace: ? __die+0x20/0x70 ? page_fault_oops+0x15b/0x430 ? fixup_exception+0x22/0x330 ? exc_page_fault+0x6f/0x170 ? asm_exc_page_fault+0x22/0x30 ? bpf_tracing_prog_attach+0x279/0x560 ? btf_obj_id+0x5/0x10 bpf_tracing_prog_attach+0x439/0x560 __sys_bpf+0x1cf4/0x2de0 __x64_sys_bpf+0x1c/0x30 do_syscall_64+0x41/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76

Return -EINVAL in this situation.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Name Vendor Start Version End Version
Linux_kernel Linux * *
Linux_kernel Linux 5.16.0 *
Linux_kernel Linux 6.2.0 *
Linux_kernel Linux 6.7.0 *

Potential Mitigations

References