From 6b8cc1d11ef75c5b9c530b3d0d148f3c2dd25f93 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 12 Jan 2017 11:51:32 +0100 Subject: bpf: pass original insn directly to convert_ctx_access Currently, when calling convert_ctx_access() callback for the various program types, we pass in insn->dst_reg, insn->src_reg, insn->off from the original instruction. This information is needed to rewrite the instruction that is based on the user ctx structure into a kernel representation for the ctx. As we'd like to allow access size beyond just BPF_W, we'd need also insn->code for that in order to decode the original access size. Given that, lets just pass insn directly to the convert_ctx_access() callback and work on that to not clutter the callback with even more arguments we need to pass when everything is already contained in insn. So lets go through that once, no functional change. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/linux/bpf.h | 7 ++- kernel/bpf/verifier.c | 3 +- kernel/trace/bpf_trace.c | 15 ++--- net/core/filter.c | 139 +++++++++++++++++++++++++---------------------- 4 files changed, 87 insertions(+), 77 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 94ea8d2383e6..f8c3560b01db 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -161,9 +161,10 @@ struct bpf_verifier_ops { enum bpf_reg_type *reg_type); int (*gen_prologue)(struct bpf_insn *insn, bool direct_write, const struct bpf_prog *prog); - u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg, - int src_reg, int ctx_off, - struct bpf_insn *insn, struct bpf_prog *prog); + u32 (*convert_ctx_access)(enum bpf_access_type type, + const struct bpf_insn *src, + struct bpf_insn *dst, + struct bpf_prog *prog); }; struct bpf_prog_type_list { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 2efdc9128e3c..df7e47244e75 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3177,8 +3177,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) if (env->insn_aux_data[i].ptr_type != PTR_TO_CTX) continue; - cnt = ops->convert_ctx_access(type, insn->dst_reg, insn->src_reg, - insn->off, insn_buf, env->prog); + cnt = ops->convert_ctx_access(type, insn, insn_buf, env->prog); if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf)) { verbose("bpf verifier is misconfigured\n"); return -EINVAL; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f883c43c96f3..1860e7f1e5a8 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -572,28 +572,29 @@ static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type return true; } -static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, int dst_reg, - int src_reg, int ctx_off, +static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, struct bpf_insn *insn_buf, struct bpf_prog *prog) { struct bpf_insn *insn = insn_buf; - switch (ctx_off) { + switch (si->off) { case offsetof(struct bpf_perf_event_data, sample_period): BUILD_BUG_ON(FIELD_SIZEOF(struct perf_sample_data, period) != sizeof(u64)); *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, - data), dst_reg, src_reg, + data), si->dst_reg, si->src_reg, offsetof(struct bpf_perf_event_data_kern, data)); - *insn++ = BPF_LDX_MEM(BPF_DW, dst_reg, dst_reg, + *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, offsetof(struct perf_sample_data, period)); break; default: *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, - regs), dst_reg, src_reg, + regs), si->dst_reg, si->src_reg, offsetof(struct bpf_perf_event_data_kern, regs)); - *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), dst_reg, dst_reg, ctx_off); + *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, + si->off); break; } diff --git a/net/core/filter.c b/net/core/filter.c index f4d16a905754..8cfbdefbfb1c 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2972,32 +2972,33 @@ void bpf_warn_invalid_xdp_action(u32 act) } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); -static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, - int src_reg, int ctx_off, +static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, struct bpf_insn *insn_buf, struct bpf_prog *prog) { struct bpf_insn *insn = insn_buf; + int off; - switch (ctx_off) { + switch (si->off) { case offsetof(struct __sk_buff, len): BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, len)); break; case offsetof(struct __sk_buff, protocol): BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); - *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, offsetof(struct sk_buff, protocol)); break; case offsetof(struct __sk_buff, vlan_proto): BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); - *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, offsetof(struct sk_buff, vlan_proto)); break; @@ -3005,17 +3006,17 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, priority)); else - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, priority)); break; case offsetof(struct __sk_buff, ingress_ifindex): BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, skb_iif) != 4); - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, skb_iif)); break; @@ -3023,17 +3024,17 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev), - dst_reg, src_reg, + si->dst_reg, si->src_reg, offsetof(struct sk_buff, dev)); - *insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1); - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, dst_reg, + *insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 1); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, offsetof(struct net_device, ifindex)); break; case offsetof(struct __sk_buff, hash): BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, hash)); break; @@ -3041,63 +3042,74 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, mark)); else - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sk_buff, mark)); break; case offsetof(struct __sk_buff, pkt_type): - return convert_skb_access(SKF_AD_PKTTYPE, dst_reg, src_reg, insn); + return convert_skb_access(SKF_AD_PKTTYPE, si->dst_reg, + si->src_reg, insn); case offsetof(struct __sk_buff, queue_mapping): - return convert_skb_access(SKF_AD_QUEUE, dst_reg, src_reg, insn); + return convert_skb_access(SKF_AD_QUEUE, si->dst_reg, + si->src_reg, insn); case offsetof(struct __sk_buff, vlan_present): return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT, - dst_reg, src_reg, insn); + si->dst_reg, si->src_reg, insn); case offsetof(struct __sk_buff, vlan_tci): return convert_skb_access(SKF_AD_VLAN_TAG, - dst_reg, src_reg, insn); + si->dst_reg, si->src_reg, insn); case offsetof(struct __sk_buff, cb[0]) ... offsetof(struct __sk_buff, cb[4]): BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20); prog->cb_access = 1; - ctx_off -= offsetof(struct __sk_buff, cb[0]); - ctx_off += offsetof(struct sk_buff, cb); - ctx_off += offsetof(struct qdisc_skb_cb, data); + off = si->off; + off -= offsetof(struct __sk_buff, cb[0]); + off += offsetof(struct sk_buff, cb); + off += offsetof(struct qdisc_skb_cb, data); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, ctx_off); + *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, + si->src_reg, off); else - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, ctx_off); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, + si->src_reg, off); break; case offsetof(struct __sk_buff, tc_classid): - ctx_off -= offsetof(struct __sk_buff, tc_classid); - ctx_off += offsetof(struct sk_buff, cb); - ctx_off += offsetof(struct qdisc_skb_cb, tc_classid); + BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, tc_classid) != 2); + + off = si->off; + off -= offsetof(struct __sk_buff, tc_classid); + off += offsetof(struct sk_buff, cb); + off += offsetof(struct qdisc_skb_cb, tc_classid); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, ctx_off); + *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg, + si->src_reg, off); else - *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, ctx_off); + *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, + si->src_reg, off); break; case offsetof(struct __sk_buff, data): *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, data), - dst_reg, src_reg, + si->dst_reg, si->src_reg, offsetof(struct sk_buff, data)); break; case offsetof(struct __sk_buff, data_end): - ctx_off -= offsetof(struct __sk_buff, data_end); - ctx_off += offsetof(struct sk_buff, cb); - ctx_off += offsetof(struct bpf_skb_data_end, data_end); - *insn++ = BPF_LDX_MEM(BPF_SIZEOF(void *), dst_reg, src_reg, - ctx_off); + off = si->off; + off -= offsetof(struct __sk_buff, data_end); + off += offsetof(struct sk_buff, cb); + off += offsetof(struct bpf_skb_data_end, data_end); + *insn++ = BPF_LDX_MEM(BPF_SIZEOF(void *), si->dst_reg, + si->src_reg, off); break; case offsetof(struct __sk_buff, tc_index): @@ -3105,110 +3117,107 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, tc_index) != 2); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, + *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg, si->src_reg, offsetof(struct sk_buff, tc_index)); else - *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, offsetof(struct sk_buff, tc_index)); - break; #else if (type == BPF_WRITE) - *insn++ = BPF_MOV64_REG(dst_reg, dst_reg); + *insn++ = BPF_MOV64_REG(si->dst_reg, si->dst_reg); else - *insn++ = BPF_MOV64_IMM(dst_reg, 0); - break; + *insn++ = BPF_MOV64_IMM(si->dst_reg, 0); #endif + break; } return insn - insn_buf; } static u32 sock_filter_convert_ctx_access(enum bpf_access_type type, - int dst_reg, int src_reg, - int ctx_off, + const struct bpf_insn *si, struct bpf_insn *insn_buf, struct bpf_prog *prog) { struct bpf_insn *insn = insn_buf; - switch (ctx_off) { + switch (si->off) { case offsetof(struct bpf_sock, bound_dev_if): BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_bound_dev_if) != 4); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sock, sk_bound_dev_if)); else - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sock, sk_bound_dev_if)); break; case offsetof(struct bpf_sock, family): BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_family) != 2); - *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, offsetof(struct sock, sk_family)); break; case offsetof(struct bpf_sock, type): - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sock, __sk_flags_offset)); - *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, SK_FL_TYPE_MASK); - *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, SK_FL_TYPE_SHIFT); + *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_TYPE_MASK); + *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_TYPE_SHIFT); break; case offsetof(struct bpf_sock, protocol): - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, offsetof(struct sock, __sk_flags_offset)); - *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, SK_FL_PROTO_MASK); - *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, SK_FL_PROTO_SHIFT); + *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK); + *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_PROTO_SHIFT); break; } return insn - insn_buf; } -static u32 tc_cls_act_convert_ctx_access(enum bpf_access_type type, int dst_reg, - int src_reg, int ctx_off, +static u32 tc_cls_act_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, struct bpf_insn *insn_buf, struct bpf_prog *prog) { struct bpf_insn *insn = insn_buf; - switch (ctx_off) { + switch (si->off) { case offsetof(struct __sk_buff, ifindex): BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev), - dst_reg, src_reg, + si->dst_reg, si->src_reg, offsetof(struct sk_buff, dev)); - *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, dst_reg, + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, offsetof(struct net_device, ifindex)); break; default: - return sk_filter_convert_ctx_access(type, dst_reg, src_reg, - ctx_off, insn_buf, prog); + return sk_filter_convert_ctx_access(type, si, insn_buf, prog); } return insn - insn_buf; } -static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg, - int src_reg, int ctx_off, +static u32 xdp_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, struct bpf_insn *insn_buf, struct bpf_prog *prog) { struct bpf_insn *insn = insn_buf; - switch (ctx_off) { + switch (si->off) { case offsetof(struct xdp_md, data): *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data), - dst_reg, src_reg, + si->dst_reg, si->src_reg, offsetof(struct xdp_buff, data)); break; case offsetof(struct xdp_md, data_end): *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data_end), - dst_reg, src_reg, + si->dst_reg, si->src_reg, offsetof(struct xdp_buff, data_end)); break; } -- cgit v1.2.3 From 62c7989b24dbd348c2507ee6458ebf5637d6ddb5 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 12 Jan 2017 11:51:33 +0100 Subject: bpf: allow b/h/w/dw access for bpf's cb in ctx When structs are used to store temporary state in cb[] buffer that is used with programs and among tail calls, then the generated code will not always access the buffer in bpf_w chunks. We can ease programming of it and let this act more natural by allowing for aligned b/h/w/dw sized access for cb[] ctx member. Various test cases are attached as well for the selftest suite. Potentially, this can also be reused for other program types to pass data around. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- kernel/bpf/verifier.c | 8 +- net/core/filter.c | 41 ++- tools/testing/selftests/bpf/test_verifier.c | 442 +++++++++++++++++++++++++++- 3 files changed, 478 insertions(+), 13 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index df7e47244e75..d60e12c67266 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3165,10 +3165,14 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) insn = env->prog->insnsi + delta; for (i = 0; i < insn_cnt; i++, insn++) { - if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) || + if (insn->code == (BPF_LDX | BPF_MEM | BPF_B) || + insn->code == (BPF_LDX | BPF_MEM | BPF_H) || + insn->code == (BPF_LDX | BPF_MEM | BPF_W) || insn->code == (BPF_LDX | BPF_MEM | BPF_DW)) type = BPF_READ; - else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) || + else if (insn->code == (BPF_STX | BPF_MEM | BPF_B) || + insn->code == (BPF_STX | BPF_MEM | BPF_H) || + insn->code == (BPF_STX | BPF_MEM | BPF_W) || insn->code == (BPF_STX | BPF_MEM | BPF_DW)) type = BPF_WRITE; else diff --git a/net/core/filter.c b/net/core/filter.c index 8cfbdefbfb1c..90383860e224 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2776,11 +2776,33 @@ static bool __is_valid_access(int off, int size) { if (off < 0 || off >= sizeof(struct __sk_buff)) return false; + /* The verifier guarantees that size > 0. */ if (off % size != 0) return false; - if (size != sizeof(__u32)) - return false; + + switch (off) { + case offsetof(struct __sk_buff, cb[0]) ... + offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1: + if (size == sizeof(__u16) && + off > offsetof(struct __sk_buff, cb[4]) + sizeof(__u16)) + return false; + if (size == sizeof(__u32) && + off > offsetof(struct __sk_buff, cb[4])) + return false; + if (size == sizeof(__u64) && + off > offsetof(struct __sk_buff, cb[2])) + return false; + if (size != sizeof(__u8) && + size != sizeof(__u16) && + size != sizeof(__u32) && + size != sizeof(__u64)) + return false; + break; + default: + if (size != sizeof(__u32)) + return false; + } return true; } @@ -2799,7 +2821,7 @@ static bool sk_filter_is_valid_access(int off, int size, if (type == BPF_WRITE) { switch (off) { case offsetof(struct __sk_buff, cb[0]) ... - offsetof(struct __sk_buff, cb[4]): + offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1: break; default: return false; @@ -2823,7 +2845,7 @@ static bool lwt_is_valid_access(int off, int size, case offsetof(struct __sk_buff, mark): case offsetof(struct __sk_buff, priority): case offsetof(struct __sk_buff, cb[0]) ... - offsetof(struct __sk_buff, cb[4]): + offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1: break; default: return false; @@ -2915,7 +2937,7 @@ static bool tc_cls_act_is_valid_access(int off, int size, case offsetof(struct __sk_buff, tc_index): case offsetof(struct __sk_buff, priority): case offsetof(struct __sk_buff, cb[0]) ... - offsetof(struct __sk_buff, cb[4]): + offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1: case offsetof(struct __sk_buff, tc_classid): break; default: @@ -3066,8 +3088,11 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, si->dst_reg, si->src_reg, insn); case offsetof(struct __sk_buff, cb[0]) ... - offsetof(struct __sk_buff, cb[4]): + offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1: BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20); + BUILD_BUG_ON((offsetof(struct sk_buff, cb) + + offsetof(struct qdisc_skb_cb, data)) % + sizeof(__u64)); prog->cb_access = 1; off = si->off; @@ -3075,10 +3100,10 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, off += offsetof(struct sk_buff, cb); off += offsetof(struct qdisc_skb_cb, data); if (type == BPF_WRITE) - *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, + *insn++ = BPF_STX_MEM(BPF_SIZE(si->code), si->dst_reg, si->src_reg, off); else - *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, + *insn++ = BPF_LDX_MEM(BPF_SIZE(si->code), si->dst_reg, si->src_reg, off); break; diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 9bb45346dc72..1aa73241c999 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -859,15 +859,451 @@ static struct bpf_test tests[] = { .result = REJECT, }, { - "check non-u32 access to cb", + "check cb access: byte", .insns = { - BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_1, + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0])), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) + 1), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) + 2), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) + 3), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1])), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1]) + 1), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1]) + 2), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1]) + 3), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2])), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2]) + 1), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2]) + 2), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2]) + 3), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3])), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3]) + 1), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3]) + 2), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3]) + 3), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4])), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 1), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 2), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 3), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0])), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) + 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) + 2), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) + 3), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1])), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1]) + 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1]) + 2), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1]) + 3), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2])), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2]) + 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2]) + 2), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2]) + 3), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3])), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3]) + 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3]) + 2), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3]) + 3), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4])), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 2), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 3), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "check cb access: byte, oob 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 4), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: byte, oob 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) - 1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: byte, oob 3", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 4), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: byte, oob 4", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) - 1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: byte, wrong type", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0])), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK, + }, + { + "check cb access: half", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0])), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) + 2), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1])), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1]) + 2), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2])), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2]) + 2), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3])), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3]) + 2), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4])), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 2), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0])), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) + 2), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1])), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1]) + 2), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2])), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2]) + 2), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3])), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3]) + 2), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4])), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 2), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "check cb access: half, unaligned", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) + 1), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: half, oob 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 4), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: half, oob 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) - 2), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: half, oob 3", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 4), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: half, oob 4", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) - 2), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: half, wrong type", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0])), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK, + }, + { + "check cb access: word", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4])), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0])), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[1])), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2])), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[3])), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4])), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "check cb access: word, unaligned 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) + 2), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: word, unaligned 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 1), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: word, unaligned 3", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 2), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: word, unaligned 4", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 3), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: double", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0])), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[2])), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0])), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[2])), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "check cb access: double, unaligned 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[1])), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: double, unaligned 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[3])), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "check cb access: double, oob 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4])), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: double, oob 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[4]) + 8), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: double, oob 3", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, + offsetof(struct __sk_buff, cb[0]) - 8), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: double, oob 4", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4])), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: double, oob 5", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[4]) + 8), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: double, oob 6", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, cb[0]) - 8), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_context access", + .result = REJECT, + }, + { + "check cb access: double, wrong type", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, offsetof(struct __sk_buff, cb[0])), BPF_EXIT_INSN(), }, .errstr = "invalid bpf_context access", - .errstr_unpriv = "R1 leaks addr", .result = REJECT, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK, }, { "check out of range skb->cb access", -- cgit v1.2.3