1.5 KiB
CVE-2024-42072
Description
In the Linux kernel, the following vulnerability has been resolved:bpf: Fix may_goto with negative offset.Zac's syzbot crafted a bpf prog that exposed two bugs in may_goto.The 1st bug is the way may_goto is patched. When offset is negativeit should be patched differently.The 2nd bug is in the verifier:when current state may_goto_depth is equal to visited state may_goto_depthit means there is an actual infinite loop. It's not correct to pruneexploration of the program at this point.Note, that this check doesn't limit the program to only one may_goto insn,since 2nd and any further may_goto will increment may_goto_depth onlyin the queued state pushed for future exploration. The current statewill have may_goto_depth == 0 regardless of number of may_goto insnsand the verifier has to explore the program until bpf_exit.
POC
Reference
No PoCs from references.