projects / pve-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 035dbe67 FG |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| 2 | From: Elena Reshetova <elena.reshetova@intel.com> | |
| 3 | Date: Mon, 4 Sep 2017 13:11:44 +0300 | |
| 4 | Subject: [PATCH] bpf: prevent speculative execution in eBPF interpreter | |
| 5 | MIME-Version: 1.0 | |
| 6 | Content-Type: text/plain; charset=UTF-8 | |
| 7 | Content-Transfer-Encoding: 8bit | |
| 8 | ||
| 9 | CVE-2017-5753 | |
| 10 | CVE-2017-5715 | |
| 11 | ||
| 12 | This adds a generic memory barrier before LD_IMM_DW and | |
| 13 | LDX_MEM_B/H/W/DW eBPF instructions during eBPF program | |
| 14 | execution in order to prevent speculative execution on out | |
| 15 | of bound BFP_MAP array indexes. This way an arbitary kernel | |
| 16 | memory is not exposed through side channel attacks. | |
| 17 | ||
| 18 | For more details, please see this Google Project Zero report: tbd | |
| 19 | ||
| 20 | Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> | |
| 21 | Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> | |
| 22 | Signed-off-by: Andy Whitcroft <apw@canonical.com> | |
| 23 | Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> | |
| 24 | (cherry picked from commit dd13f73106c260dea7a689d33d1457639af820aa) | |
| 25 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
| 26 | --- | |
| 27 | kernel/bpf/core.c | 3 +++ | |
| 28 | 1 file changed, 3 insertions(+) | |
| 29 | ||
| 30 | diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c | |
| 31 | index 9a1bed1f3029..3f83c60e3e86 100644 | |
| 32 | --- a/kernel/bpf/core.c | |
| 33 | +++ b/kernel/bpf/core.c | |
| 34 | @@ -33,6 +33,7 @@ | |
| 35 | #include <linux/rcupdate.h> | |
| 36 | ||
| 37 | #include <asm/unaligned.h> | |
| 38 | +#include <asm/barrier.h> | |
| 39 | ||
| 40 | /* Registers */ | |
| 41 | #define BPF_R0 regs[BPF_REG_0] | |
| 42 | @@ -920,6 +921,7 @@ static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, | |
| 43 | DST = IMM; | |
| 44 | CONT; | |
| 45 | LD_IMM_DW: | |
| 46 | + gmb(); | |
| 47 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
| 48 | insn++; | |
| 49 | CONT; | |
| 50 | @@ -1133,6 +1135,7 @@ static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, | |
| 51 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
| 52 | CONT; \ | |
| 53 | LDX_MEM_##SIZEOP: \ | |
| 54 | + gmb(); \ | |
| 55 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
| 56 | CONT; | |
| 57 | ||
| 58 | -- | |
| 59 | 2.14.2 | |
| 60 |