CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of certain BPF kfunc arguments, specifically rdonly_buf_size and rdwr_buf_size, which can exceed the maximum value for a 32-bit unsigned integer (U32_MAX). This oversight allows for potential memory allocation issues, as the kernel may incorrectly truncate values, leading to improper access checks and possible exploitation. Organizations using the Linux kernel, particularly those relying on BPF for network or system performance enhancements, should prioritize addressing this vulnerability to mitigate risks of memory corruption or denial-of-service scenarios.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max check_kfunc_args() detects a kfunc argument named rdonly_buf_size or rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64, and does not bound it. check_kfunc_call() later copies that value into the returned register's mem_size field: meta->r0_size = reg->var_off.value; ... regs[BPF_REG_0].mem_size = meta.r0_size; regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set gets truncated instead of causing a load-time rejection, so the verifier records a PTR_TO_MEM register with an approximately 4 GiB mem_size for whatever allocation the kfunc returned. A later access check against that register uses the truncated, wrong bound. Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the point meta->r0_size is set.