diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0099-bpf-arsh-is-not-supported-in-32-bit-alu-thus-reject-.patch')
-rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0099-bpf-arsh-is-not-supported-in-32-bit-alu-thus-reject-.patch | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0099-bpf-arsh-is-not-supported-in-32-bit-alu-thus-reject-.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0099-bpf-arsh-is-not-supported-in-32-bit-alu-thus-reject-.patch new file mode 100644 index 00000000..acbc5668 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0099-bpf-arsh-is-not-supported-in-32-bit-alu-thus-reject-.patch @@ -0,0 +1,50 @@ +From d4d31ba0cca574288cdaef8002d11cf27b300d0f Mon Sep 17 00:00:00 2001 +From: Daniel Borkmann <daniel@iogearbox.net> +Date: Mon, 29 Jan 2018 02:48:57 +0100 +Subject: [PATCH 099/103] bpf: arsh is not supported in 32 bit alu thus reject + it + +[ upstream commit 7891a87efc7116590eaba57acc3c422487802c6f ] + +The following snippet was throwing an 'unknown opcode cc' warning +in BPF interpreter: + + 0: (18) r0 = 0x0 + 2: (7b) *(u64 *)(r10 -16) = r0 + 3: (cc) (u32) r0 s>>= (u32) r0 + 4: (95) exit + +Although a number of JITs do support BPF_ALU | BPF_ARSH | BPF_{K,X} +generation, not all of them do and interpreter does neither. We can +leave existing ones and implement it later in bpf-next for the +remaining ones, but reject this properly in verifier for the time +being. + +Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") +Reported-by: syzbot+93c4904c5c70348a6890@syzkaller.appspotmail.com +Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> +Signed-off-by: Alexei Starovoitov <ast@kernel.org> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + kernel/bpf/verifier.c | 5 +++++ + 1 file changed, 5 insertions(+) + +diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c +index 6767670..6caf0ff1 100644 +--- a/kernel/bpf/verifier.c ++++ b/kernel/bpf/verifier.c +@@ -1753,6 +1753,11 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) + return -EINVAL; + } + ++ if (opcode == BPF_ARSH && BPF_CLASS(insn->code) != BPF_ALU64) { ++ verbose("BPF_ARSH not supported for 32 bit ALU\n"); ++ return -EINVAL; ++ } ++ + if ((opcode == BPF_LSH || opcode == BPF_RSH || + opcode == BPF_ARSH) && BPF_SRC(insn->code) == BPF_K) { + int size = BPF_CLASS(insn->code) == BPF_ALU64 ? 64 : 32; +-- +2.7.4 + |