CVE-2024-49888

CVE-2024-49888 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

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/

Frequently asked questions

What is CVE-2024-49888?
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/
How severe is CVE-2024-49888?
CVE-2024-49888 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-49888 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-49888?
CVE-2024-49888 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-49888?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-49888 have an EU (EUVD) identifier?
Yes. CVE-2024-49888 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-43588.
When was CVE-2024-49888 published?
CVE-2024-49888 was published on 2024-10-21 and last updated on 2026-06-17.

References

Affected products (1)

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