In the Linux kernel, the following vulnerability has been resolved:
bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
For all non-tracing helpers which formerly had ARG_PTR_TO_{LONG,INT} as input
arguments, zero the value for the case of an error as otherwise it could leak
memory. For tracing, it is not needed given CAP_PERFMON can already read all
kernel memory anyway hence bpf_get_func_arg() and bpf_get_func_ret() is skipped
in here.
Also, the MTU helpers mtu_len pointer value is being written but also read.
Technically, the MEM_UNINIT should not be there in order to always force init.
Removing MEM_UNINIT needs more verifier rework though: MEM_UNINIT right now
implies two things actually: i) write into memory, ii) memory does not have
to be initialized. If we lift MEM_UNINIT, it then becomes: i) read into memory,
ii) memory must be initialized. This means that for bpf_*_check_mtu() we're
readding the issue we're trying to fix, that is, it would then be able to
write back into things like .rodata BPF maps. Follow-up work will rework the
MEM_UNINIT semantics such that the intent can be better expressed. For now
just clear the *mtu_len on error path which can be lifted later again.
References
Configurations
Configuration 1 (hide)
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History
No history.
Information
Published : 2024-10-21 13:15
Updated : 2024-10-23 20:36
NVD link : CVE-2024-47728
Mitre link : CVE-2024-47728
CVE.ORG link : CVE-2024-47728
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-459
Incomplete Cleanup