From: Björn Töpel <bjorn@kernel.org>
Date: Thu, 28 Oct 2021 12:51:15 +0000 (+0200)
Subject: riscv, bpf: Fix potential NULL dereference
X-Git-Tag: xarray-5.18~775^2~2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=27de809a3d83a6199664479ebb19712533d6fd9b;p=users%2Fwilly%2Fxarray.git

riscv, bpf: Fix potential NULL dereference

The bpf_jit_binary_free() function requires a non-NULL argument. When
the RISC-V BPF JIT fails to converge in NR_JIT_ITERATIONS steps,
jit_data->header will be NULL, which triggers a NULL
dereference. Avoid this by checking the argument, prior calling the
function.

Fixes: ca6cb5447cec ("riscv, bpf: Factor common RISC-V JIT code")
Signed-off-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20211028125115.514587-1-bjorn@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c
index 0fee2cbaaf53..753d85bdfad0 100644
--- a/arch/riscv/net/bpf_jit_core.c
+++ b/arch/riscv/net/bpf_jit_core.c
@@ -125,7 +125,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 
 	if (i == NR_JIT_ITERATIONS) {
 		pr_err("bpf-jit: image did not converge in <%d passes!\n", i);
-		bpf_jit_binary_free(jit_data->header);
+		if (jit_data->header)
+			bpf_jit_binary_free(jit_data->header);
 		prog = orig_prog;
 		goto out_offset;
 	}