CVE-2026-98547

CVE-2026-98547CVE-2026-98547

Description

In the Linux kernel, the following vulnerability has been resolved: af_packet: fix integer overflow in prb_calc_retire_blk_tmo() prb_calc_retire_blk_tmo() computes in 32-bit int arithmetic: mbits = (blk_size_in_bytes * 8) / (1024 * 1024); If I'm reading the validation right, tp_block_size is user controlled and packet_set_ring() only rejects values that are <= 0 as int or not page aligned, so a 256MiB block goes right through (and alloc_one_pg_vec_page() even has a vzalloc fallback for it). 0x10000000 * 8 wraps to INT_MIN, and on a NIC reporting 1 Gbps (div == 1) the function ends up returning -2047. The condition is actually (8 * size) mod 2^32 >= 2^31 && div == 1, so the trigger set is [256,512), [768,1024), [1280,1536) and [1792,2048) MiB. Other sizes wrap to non-negative values and faster links divide the unsigned value back below 2^31, which is why this doesn't blow up for everyone. What makes it fatal is what happens next in init_prb_bdqc(): p1->interval_kt

Scoring

Last modified2026-10-18
Sourced from NVD. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.