From: Daniel Borkmann daniel@iogearbox.net
commit b4e76f7e6d3200462c6354a6ad4ae167459e61f8 upstream.
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@oracle.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Cc: Alexei Starovoitov ast@kernel.org Cc: ast@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13814/ Signed-off-by: Ralf Baechle ralf@linux-mips.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/mips/net/bpf_jit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -1207,7 +1207,7 @@ 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;