[PATCH bpf] riscv, bpf: Fix potential NULL dereference
From: Björn Töpel <bjorn@kernel.org>
Date: 2021-10-28 12:52:50
Also in:
bpf, linux-riscv
Subsystem:
bpf jit for risc-v (32-bit), bpf jit for risc-v (64-bit), bpf [general] (safe dynamic programs and tools), risc-v architecture, the rest · Maintainers:
Luke Nelson, Xi Wang, Björn Töpel, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
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>
---
arch/riscv/net/bpf_jit_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
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; }
base-commit: 72f898ca0ab85fde6facf78b14d9f67a4a7b32d1 -- 2.32.0