From: Hengqi Chen Date: Wed, 31 Dec 2025 07:19:20 +0000 (+0800) Subject: LoongArch: BPF: Zero-extend bpf_tail_call() index X-Git-Tag: v6.19-rc4~11^2~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eb71f5c433e1c6dff089b315881dec40a88a7baf;p=thirdparty%2Flinux.git 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 Signed-off-by: Huacai Chen --- diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 5352d0c30fb2..766ded335fd8 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -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 */