CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of the Block Translation Table (BTT) in non-volatile memory, where insufficient validation of the nfree field can lead to out-of-bounds writes in the freelist and rtt arrays. This flaw could potentially allow an attacker to manipulate memory allocation, leading to data corruption or system instability. Organizations using Linux systems that leverage nvdimm technology should prioritize patching this vulnerability to mitigate the risk of exploitation.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: nvdimm/btt: reject an arena whose nfree is below the lane count The BTT info block's nfree field, the number of reserve free blocks, is read from the medium without validation. btt_freelist_init() and btt_rtt_init() size the per-lane freelist[] and rtt[] arrays by nfree, but the I/O path indexes them by the lane from nd_region_acquire_lane(), which is bounded by nd_region->num_lanes (ND_MAX_LANES), not by nfree. A crafted or foreign arena whose nfree is below the lane count makes freelist[lane]/rtt[lane] run past the allocation: an out-of-bounds write. btt.rst documents the nlanes = min(nfree, num_cpus) invariant, which the code does not currently honor: num_lanes is ND_MAX_LANES regardless of nfree. Reject an arena whose nfree is below num_lanes at discovery, before the per-lane arrays are allocated, enforcing that invariant.