CVE-2024-49888

MEDIUM EPSS 14.2%
Published Oct 21, 20241y ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
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Published Oct 21, 2024 1y ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a sdiv overflow issue Zac Ecob reported a problem where a bpf program may cause kernel crash due to the following error: Oops: divide error: 0000 [#1] PREEMPT SMP KASAN PTI The failure is due to the below signed divide: LLONG_MIN/-1 where LLONG_MIN equals to -9,223,372,036,854,775,808. LLONG_MIN/-1 is supposed to give a positive number 9,223,372,036,854,775,808, but it is impossible since for 64-bit system, the maximum positive number is 9,223,372,036,854,775,807. On x86_64, LLONG_MIN/-1 will cause a kernel exception. On arm64, the result for LLONG_MIN/-1 is LLONG_MIN. Further investigation found all the following sdiv/smod cases may trigger an exception when bpf program is running on x86_64 platform: - LLONG_MIN/-1 for 64bit operation - INT_MIN/-1 for 32bit operation - LLONG_MIN%-1 for 64bit operation - INT_MIN%-1 for 32bit operation where -1 can be an immediate or in a register. On arm64, there are no exceptions: - LLONG_MIN/-1 = LLONG_MIN - INT_MIN/-1 = INT_MIN - LLONG_MIN%-1 = 0 - INT_MIN%-1 = 0 where -1 can be an immediate or in a register. Insn patching is needed to handle the above cases and the patched codes produced results aligned with above arm64 result. The below are pseudo codes to handle sdiv/smod exceptions including both divisor -1 and divisor 0 and the divisor is stored in a register. sdiv: tmp = rX tmp += 1 /* [-1, 0] -> [0, 1] if tmp >(unsigned) 1 goto L2 if tmp == 0 goto L1 rY = 0 L1: rY = -rY; goto L3 L2: rY /= rX L3: smod: tmp = rX tmp += 1 /* [-1, 0] -> [0, 1] if tmp >(unsigned) 1 goto L1 if tmp == 1 (is64 ? goto L2 : goto L3) rY = 0; goto L2 L1: rY %= rX L2: goto L4 // only when !is64 L3: wY = wY // only when !is64 L4: [1] https://lore.kernel.org/bpf/tPJLTEh7S_DxFEqAI2Ji5MBSoZVg7_G-Py2iaZpAaWtM961fFTWtsnlzwvTbzBzaUzwQAoNATXKUlt0LZOFgnDcIyKCswAnAGdUF3LBrhGQ=@protonmail.com/

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
14.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-190 Integer Overflow or Wraparound Numeric Error

Affected Products 2

VendorProductVersionRange
linuxlinux_kernel* <6.10.14
linuxlinux_kernel*≥6.11  –  <6.11.3

References 3

  • git.kernel.org https://git.kernel.org/stable/c/4902a6a0dc593c82055fc8c9ada371bafe26c9cc
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7dd34d7b7dcf9309fc6224caf4dd5b35bedddcb7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/d22e45a369afc7c28f11acfa5b5e8e478227ca5d
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/4902a6a0dc593c82055fc8c9ada371bafe26c9cc
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7dd34d7b7dcf9309fc6224caf4dd5b35bedddcb7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/d22e45a369afc7c28f11acfa5b5e8e478227ca5d
    Patch