Dan Carpenter reported [1] a static checker warning that ctx->offsets[] may be accessed off by one from build_body(), since it's allocated with fp->len * sizeof(*ctx.offsets) as length. The cBPF arm and ppc code doesn't have this issue as claimed, so only mips seems to be affected and should like most other JITs allocate with fp->len + 1. A few number of JITs (x86, sparc, arm64) handle this differently, where they only require fp->len array elements. [1] http://www.spinics.net/lists/mips/msg64193.html Fixes: c6610de353da ("MIPS: net: Add BPF JIT") Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Cc: Markos Chandras <markos.chandras@xxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx --- arch/mips/net/bpf_jit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c index 1a8c960..a04c393 100644 --- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -1199,7 +1199,7 @@ void bpf_jit_compile(struct bpf_prog *fp) memset(&ctx, 0, sizeof(ctx)); - ctx.offsets = kcalloc(fp->len, sizeof(*ctx.offsets), GFP_KERNEL); + ctx.offsets = kcalloc(fp->len + 1, sizeof(*ctx.offsets), GFP_KERNEL); if (ctx.offsets == NULL) return; -- 1.9.3
