LoongArch: BPF: Zero-extend bpf_tail_call() index

The bpf_tail_call() index should be treated as a u32 value. Let's
zero-extend it to avoid calling wrong BPF progs. See similar fixes
for x86 [1]) and arm64 ([2]) for more details.

  [1]: https://github.com/torvalds/linux/commit/90caccdd8cc0215705f18b92771b449b01e2474a
  [2]: https://github.com/torvalds/linux/commit/16338a9b3ac30740d49f5dfed81bac0ffa53b9c7

Cc: stable@vger.kernel.org
Fixes: 5dc615520c4d ("LoongArch: Add BPF JIT support")
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
This commit is contained in:
Hengqi Chen
2026-02-04 16:41:29 +08:00
committed by maoxiaochuan
parent e49a3e7382
commit 290577b9a2
+2
View File
@@ -280,6 +280,8 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int insn)
* goto out;
*/
tc_ninsn = insn ? ctx->offset[insn+1] - ctx->offset[insn] : ctx->offset[0];
emit_zext_32(ctx, a2, true);
off = offsetof(struct bpf_array, map.max_entries);
emit_insn(ctx, ldwu, t1, a1, off);
/* bgeu $a2, $t1, jmp_offset */