This is a note to let you know that I've just added the patch titled
selftests/bpf: Extend verifier and bpf_sock tests for dst_port loads
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-bpf-extend-verifier-and-bpf_sock-tests-for-dst_port-loads.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Aug 3 05:24:03 PM CEST 2022
From: Ovidiu Panait <ovidiu.panait@xxxxxxxxxxxxx>
Date: Wed, 3 Aug 2022 17:50:02 +0300
Subject: selftests/bpf: Extend verifier and bpf_sock tests for dst_port loads
To: stable@xxxxxxxxxxxxxxx
Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>, Alexei Starovoitov <ast@xxxxxxxxxx>, Ovidiu Panait <ovidiu.panait@xxxxxxxxxxxxx>
Message-ID: <20220803145005.2385039-3-ovidiu.panait@xxxxxxxxxxxxx>
From: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
commit 8f50f16ff39dd4e2d43d1548ca66925652f8aff7 upstream.
Add coverage to the verifier tests and tests for reading bpf_sock fields to
ensure that 32-bit, 16-bit, and 8-bit loads from dst_port field are allowed
only at intended offsets and produce expected values.
While 16-bit and 8-bit access to dst_port field is straight-forward, 32-bit
wide loads need be allowed and produce a zero-padded 16-bit value for
backward compatibility.
Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220130115518.213259-3-jakub@xxxxxxxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
[OP: backport to 5.4: cherry-pick verifier changes only]
Signed-off-by: Ovidiu Panait <ovidiu.panait@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/include/uapi/linux/bpf.h | 3 -
tools/testing/selftests/bpf/verifier/sock.c | 81 ++++++++++++++++++++++++++--
2 files changed, 80 insertions(+), 4 deletions(-)
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3068,7 +3068,8 @@ struct bpf_sock {
__u32 src_ip4;
__u32 src_ip6[4];
__u32 src_port; /* host byte order */
- __u32 dst_port; /* network byte order */
+ __be16 dst_port; /* network byte order */
+ __u16 :16; /* zero padding */
__u32 dst_ip4;
__u32 dst_ip6[4];
__u32 state;
--- a/tools/testing/selftests/bpf/verifier/sock.c
+++ b/tools/testing/selftests/bpf/verifier/sock.c
@@ -121,7 +121,25 @@
.result = ACCEPT,
},
{
- "sk_fullsock(skb->sk): sk->dst_port [narrow load]",
+ "sk_fullsock(skb->sk): sk->dst_port [word load] (backward compatibility)",
+ .insns = {
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ .result = ACCEPT,
+},
+{
+ "sk_fullsock(skb->sk): sk->dst_port [half load]",
.insns = {
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
@@ -139,7 +157,64 @@
.result = ACCEPT,
},
{
- "sk_fullsock(skb->sk): sk->dst_port [load 2nd byte]",
+ "sk_fullsock(skb->sk): sk->dst_port [half load] (invalid)",
+ .insns = {
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ .result = REJECT,
+ .errstr = "invalid sock access",
+},
+{
+ "sk_fullsock(skb->sk): sk->dst_port [byte load]",
+ .insns = {
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_B, BPF_REG_2, BPF_REG_0, offsetof(struct bpf_sock, dst_port)),
+ BPF_LDX_MEM(BPF_B, BPF_REG_2, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 1),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ .result = ACCEPT,
+},
+{
+ "sk_fullsock(skb->sk): sk->dst_port [byte load] (invalid)",
+ .insns = {
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ .result = REJECT,
+ .errstr = "invalid sock access",
+},
+{
+ "sk_fullsock(skb->sk): past sk->dst_port [half load] (invalid)",
.insns = {
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
@@ -149,7 +224,7 @@
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
- BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 1),
+ BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_0, offsetofend(struct bpf_sock, dst_port)),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
Patches currently in stable-queue which might be from ovidiu.panait@xxxxxxxxxxxxx are
queue-5.4/bpf-verifer-adjust_scalar_min_max_vals-to-always-call-update_reg_bounds.patch
queue-5.4/selftests-bpf-fix-dubious-pointer-arithmetic-test.patch
queue-5.4/selftests-bpf-extend-verifier-and-bpf_sock-tests-for-dst_port-loads.patch
queue-5.4/selftests-bpf-fix-test_align-verifier-log-patterns.patch
queue-5.4/bpf-test_verifier-70-error-message-updates-for-32-bit-right-shift.patch
