CVE-2025-39917

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt Stanislav reported that in bpf_crypto_crypt() the destination dynptr's size is not validated to be at least as large as the source dynptr's size before calling into the crypto backend with 'len = src_len'. This can result in an OOB write when the destination is smaller than the source. Concretely, in mentioned function, psrc and pdst are both linear buffers fetched from each dynptr: psrc = __bpf_dynptr_data(src, src_len); [...] pdst = __bpf_dynptr_data_rw(dst, dst_len); [...] err = decrypt ? ctx->type->decrypt(ctx->tfm, psrc, pdst, src_len, piv) : ctx->type->encrypt(ctx->tfm, psrc, pdst, src_len, piv); The crypto backend expects pdst to be large enough with a src_len length that can be written. Add an additional src_len > dst_len check and bail out if it's the case. Note that these kfuncs are accessible under root privileges only.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/0126358df12d6f476f79251d9c398ac5c1b3062d ↗
• https://git.kernel.org/stable/c/c4be24ef0510c146dca4671effb127e97631534b ↗
• https://git.kernel.org/stable/c/f9bb6ffa7f5ad0f8ee0f53fc4a10655872ee4a14 ↗