In the Linux kernel, the following vulnerability has been resolved:
xsk: Use a 32-bit compare in xsk_map_gen_lookup
xsk_map_gen_lookup() loads a u32 key and compares it with max_entries
using BPF_JMP_IMM. BPF immediates are sign-extended to 64 bits, so a
max_entries value of 0x80000000 or higher becomes a threshold larger
than every zero-extended 32-bit key. An out-of-range index then skips
the bounds check and the generated lookup reads past xsk_map[].
Compare with BPF_JMP32_IMM so the check stays in 32-bit unsigned range.
