CVE-2024-35917
What it is
In the Linux kernel, the following vulnerability has been resolved: s390/bpf: Fix bpf_plt pointer arithmetic Kui-Feng Lee reported a crash on s390x triggered by the dummy_st_ops/dummy_init_ptr_arg test [1]: [<0000000000000002>] 0x2 [<00000000009d5cde>] bpf_struct_ops_test_run+0x156/0x250 [<000000000033145a>] __sys_bpf+0xa1a/0xd00 [<00000000003319dc>] __s390x_sys_bpf+0x44/0x50 [<0000000000c4382c>] __do_syscall+0x244/0x300 [<0000000000c59a40>] system_call+0x70/0x98 This is caused by GCC moving memcpy() after assignments in bpf_jit_plt(), resulting in NULL pointers being written instead of the return and the target addresses. Looking at the GCC internals, the reordering is allowed because the alias analysis thinks that the memcpy() destination and the assignments' left-hand-sides are based on different objects: new_plt and bpf_plt_ret/bpf_plt_target respectively, and therefore they cannot alias. This is in turn due to a violation of the C standard: When two pointers are subtracted, both shall point to elements of the same array object, or one past the last element of the array object ... From the C's perspective, bpf_plt_ret and bpf_plt are distinct objects and cannot be subtracted. In the practical terms, doing so confuses the GCC's alias analysis. The code was written this way in order to let the C side know a few offsets defined in the assembly. While nice, this is by no means necessary. Fix the noncompliance by hardcoding these offsets. [1] https://lore.kernel.org/bpf/[email protected]/
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Analyzed
Affected
- Linux Kernel < 6.6.26
- Linux Kernel < 6.8.5
- Linux Kernel 6.9
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2024-35917.md and follow it. Check whether this project is affected by CVE-2024-35917. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/7ded842b356d151ece8ac4985940438e6d3998bb
- https://git.kernel.org/stable/c/c3062bdb859b6e2567e7f5c8cde20c0250bb130f
- https://git.kernel.org/stable/c/d3d74e45a060d218fe4b0c9174f0a77517509d8e
- https://git.kernel.org/stable/c/7ded842b356d151ece8ac4985940438e6d3998bb
- https://git.kernel.org/stable/c/c3062bdb859b6e2567e7f5c8cde20c0250bb130f
- https://git.kernel.org/stable/c/d3d74e45a060d218fe4b0c9174f0a77517509d8e
References
- https://git.kernel.org/stable/c/7ded842b356d151ece8ac4985940438e6d3998bb
- https://git.kernel.org/stable/c/c3062bdb859b6e2567e7f5c8cde20c0250bb130f
- https://git.kernel.org/stable/c/d3d74e45a060d218fe4b0c9174f0a77517509d8e
- https://git.kernel.org/stable/c/7ded842b356d151ece8ac4985940438e6d3998bb
- https://git.kernel.org/stable/c/c3062bdb859b6e2567e7f5c8cde20c0250bb130f
- https://git.kernel.org/stable/c/d3d74e45a060d218fe4b0c9174f0a77517509d8e