Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1639847

[PATCH 4.11 12/28] bpf, arm64: fix jit branch offset related to ldimm64

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 4.11 12/28] bpf, arm64: fix jit branch offset related to ldimm64
Date 2017-05-11 18:10 +0200
Message-ID <tFYP9-7g-55@gated-at.bofh.it> (permalink)
References <tFX6H-7p4-31@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daniel Borkmann <daniel@iogearbox.net>


[ Upstream commit ddc665a4bb4b728b4e6ecec8db1b64efa9184b9c ]

When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539ddea0 ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/net/bpf_jit_comp.c |    8 +++----
 lib/test_bpf.c                |   45 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 4 deletions(-)

--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -779,14 +779,14 @@ static int build_body(struct jit_ctx *ct
 		int ret;
 
 		ret = build_insn(insn, ctx);
-
-		if (ctx->image == NULL)
-			ctx->offset[i] = ctx->idx;
-
 		if (ret > 0) {
 			i++;
+			if (ctx->image == NULL)
+				ctx->offset[i] = ctx->idx;
 			continue;
 		}
+		if (ctx->image == NULL)
+			ctx->offset[i] = ctx->idx;
 		if (ret)
 			return ret;
 	}
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4656,6 +4656,51 @@ static struct bpf_test tests[] = {
 		{ },
 		{ { 0, 1 } },
 	},
+	{
+		/* Mainly testing JIT + imm64 here. */
+		"JMP_JGE_X: ldimm64 test 1",
+		.u.insns_int = {
+			BPF_ALU32_IMM(BPF_MOV, R0, 0),
+			BPF_LD_IMM64(R1, 3),
+			BPF_LD_IMM64(R2, 2),
+			BPF_JMP_REG(BPF_JGE, R1, R2, 2),
+			BPF_LD_IMM64(R0, 0xffffffffffffffffUL),
+			BPF_LD_IMM64(R0, 0xeeeeeeeeeeeeeeeeUL),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL,
+		{ },
+		{ { 0, 0xeeeeeeeeU } },
+	},
+	{
+		"JMP_JGE_X: ldimm64 test 2",
+		.u.insns_int = {
+			BPF_ALU32_IMM(BPF_MOV, R0, 0),
+			BPF_LD_IMM64(R1, 3),
+			BPF_LD_IMM64(R2, 2),
+			BPF_JMP_REG(BPF_JGE, R1, R2, 0),
+			BPF_LD_IMM64(R0, 0xffffffffffffffffUL),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL,
+		{ },
+		{ { 0, 0xffffffffU } },
+	},
+	{
+		"JMP_JGE_X: ldimm64 test 3",
+		.u.insns_int = {
+			BPF_ALU32_IMM(BPF_MOV, R0, 1),
+			BPF_LD_IMM64(R1, 3),
+			BPF_LD_IMM64(R2, 2),
+			BPF_JMP_REG(BPF_JGE, R1, R2, 4),
+			BPF_LD_IMM64(R0, 0xffffffffffffffffUL),
+			BPF_LD_IMM64(R0, 0xeeeeeeeeeeeeeeeeUL),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL,
+		{ },
+		{ { 0, 1 } },
+	},
 	/* BPF_JMP | BPF_JNE | BPF_X */
 	{
 		"JMP_JNE_X: if (3 != 2) return 1",

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 4.11 00/28] 4.11.1-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 13/28] tcp: fix wraparound issue in tcp_lp Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 27/28] xen: Revert commits da72ff5bfcb0 and 72a9b186292d Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 18/28] rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 26/28] xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..." Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 06/28] sparc64: fix fault handling in NGbzero.S and GENbzero.S Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 28/28] block: get rid of blk_integrity_revalidate() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 08/28] net: macb: fix phy interrupt parsing Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 23/28] bpf: dont let ldimm64 leak map addresses on unprivileged Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 22/28] bnxt_en: allocate enough space for ->ntp_fltr_bmap Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 21/28] tcp: randomize timestamps on syncookies Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 14/28] net: ipv6: Do not duplicate DAD on link up Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 16/28] tcp: do not inherit fastopen_req from parent Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 20/28] ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 09/28] tcp: fix access to sk->sk_state in tcp_poll() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 24/28] net: mdio-mux: bcm-iproc: call mdiobus_free() in error path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 12/28] bpf, arm64: fix jit branch offset related to ldimm64 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 17/28] ipv4, ipv6: ensure raw socket message is big enough to hold an IP header Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  [PATCH 4.11 19/28] ipv6: initialize route null entry in addrconf_init() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-11 18:10 +0200
  Re: [PATCH 4.11 00/28] 4.11.1-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-05-12 17:30 +0200
    Re: [PATCH 4.11 00/28] 4.11.1-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-12 17:50 +0200
    Re: [PATCH 4.11 00/28] 4.11.1-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-05-12 18:10 +0200
      Re: [PATCH 4.11 00/28] 4.11.1-stable review Matt Fleming <matt@codeblueprint.co.uk> - 2017-05-15 16:40 +0200
  Re: [PATCH 4.11 00/28] 4.11.1-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-12 22:00 +0200
    Re: [PATCH 4.11 00/28] 4.11.1-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-14 13:10 +0200

csiph-web