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.
References
Configurations
Configuration 1 (hide)
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History
19 Oct 2026, 21:10
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| Summary |
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Information
Published : 2025-10-01 08:15
Updated : 2026-10-19 21:10
NVD link : CVE-2025-39917
Mitre link : CVE-2025-39917
CVE.ORG link : CVE-2025-39917
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-787
Out-of-bounds Write