CVSS 7.8 · High EPSS 0,14%
Kerentanan Off-by-one Error pada linux kernel. Skor CVSS 3.1 7.8 (High) menurut CNA.
In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix off-by-one in check_imm signed range check check_imm(bits, imm) is used in the arm64 BPF JIT to verify that a branch displacement (in arm64 instruction units) fits into the signed N-bit immediate field of a B, B.cond or CBZ/CBNZ encoding before it is handed to the encoder. The macro currently tests for (imm > 0 && imm >> bits) || (imm < 0 && ~imm >> bits) which admits values in [-2^N, 2^N) — effectively a signed (N+1)-bit range. A signed N-bit field only holds [-2^(N-1), 2^(N-1)), so the check admits one extra bit of range on each side. In particular, for check_imm19(), values in [2^18, 2^19) slip past the check but do not fit into the 19-bit signed imm19 field of B.cond. aarch64_insn_encode_immediate() then masks the raw value into the 19-bit field, setting bit 18 (the sign bit) and flipping a forward branch into a backward one. Same class of issue exists for check_imm26() and the B/BL encoding. Shift by (bits - 1) instead of bits so the actual signed N-bit range is enforced.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 3.18 hingga sebelum 6.1.175 |
| linux | linux kernel | Versi 6.2 hingga sebelum 6.6.141 |
| linux | linux kernel | Versi 6.7 hingga sebelum 6.12.91 |
| linux | linux kernel | Versi 6.13 hingga sebelum 6.18.33 |
| linux | linux kernel | Versi 6.19 hingga sebelum 7.0.10 |