Threats Tagged 'cve-2025-40159'

A vulnerability in the Linux kernel's xsk (AF_XDP socket) subsystem related to insufficient validation of userspace-supplied xdp_desc structures has been resolved. Invalid values in xdp_desc can bypass validation checks, potentially causing undefined behavior or queuing invalid frames for transmission. Specifically, desc->len values near the maximum 32-bit unsigned integer with non-zero tx_metadata_len can cause integer overflow, and low desc->addr values can cause negative overflow, both allowing invalid data to pass validation. The issue does not affect valid XSk applications but could be exploited by crafted inputs. The fix involves promoting desc->len to 64-bit and using explicit overflow checks for desc->addr. No affected versions are explicitly stated. The vulnerability has a high severity rating based on CVSS 3.1 metrics.

In the Linux kernel, the following vulnerability has been resolved: xsk: Harden userspace-supplied xdp_desc validation Turned out certain clearly invalid values passed in xdp_desc from userspace can pass xp_{,un}aligned_validate_desc() and then lead to UBs or just invalid frames to be queued for xmit. desc->len close to ``U32_MAX`` with a non-zero pool->tx_metadata_len can cause positive integer overflow and wraparound, the same way low enough desc->addr with a non-zero pool->tx_metadata_len can cause negative integer overflow. Both scenarios can then pass the validation successfully. This doesn't happen with valid XSk applications, but can be used to perform attacks. Always promote desc->len to ``u64`` first to exclude positive overflows of it. Use explicit check_{add,sub}_overflow() when validating desc->addr (which is ``u64`` already). bloat-o-meter reports a little growth of the code size: add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-16 (44) Function old new delta xskq_cons_peek_desc 299 330 +31 xsk_tx_peek_release_desc_batch 973 1002 +29 xsk_generic_xmit 3148 3132 -16 but hopefully this doesn't hurt the performance much.