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authorLinus Torvalds <torvalds@linux-foundation.org>2015-11-04 09:41:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-04 09:41:05 -0800
commitb0f85fa11aefc4f3e03306b4cd47f113bd57dcba (patch)
tree1333d36d99fde3f97210795941fc246f0ad08a75 /kernel/bpf/verifier.c
parentccc9d4a6d640cbde05d519edeb727881646cf71b (diff)
parentf32bfb9a8ca083f8d148ea90ae5ba66f4831836e (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: Changes of note: 1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell. 2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from David Ahern. 3) Allow the user to ask for the statistics to be filtered out of ipv4/ipv6 address netlink dumps. From Sowmini Varadhan. 4) More work to pass the network namespace context around deep into various packet path APIs, starting with the netfilter hooks. From Eric W Biederman. 5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas Richter. 6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng. 7) Support Very High Throughput in wireless MESH code, from Bob Copeland. 8) Allow setting the ageing_time in switchdev/rocker. From Scott Feldman. 9) Properly autoload L2TP type modules, from Stephen Hemminger. 10) Fix and enable offload features by default in 8139cp driver, from David Woodhouse. 11) Support both ipv4 and ipv6 sockets in a single vxlan device, from Jiri Benc. 12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning Opstad. 13) Fix IPSEC flowcache overflows on large systems, from Steffen Klassert. 14) Convert bridging to track VLANs using rhashtable entries rather than a bitmap. From Nikolay Aleksandrov. 15) Make TCP listener handling completely lockless, this is a major accomplishment. Incoming request sockets now live in the established hash table just like any other socket too. From Eric Dumazet. 15) Provide more bridging attributes to netlink, from Nikolay Aleksandrov. 16) Use hash based algorithm for ipv4 multipath routing, this was very long overdue. From Peter Nørlund. 17) Several y2038 cures, mostly avoiding timespec. From Arnd Bergmann. 18) Allow non-root execution of EBPF programs, from Alexei Starovoitov. 19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet. This influences the port binding selection logic used by SO_REUSEPORT. 20) Add ipv6 support to VRF, from David Ahern. 21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko. 22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen. 23) Implement RACK loss recovery in TCP, from Yuchung Cheng. 24) Support multipath routes in MPLS, from Roopa Prabhu. 25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric Dumazet. 26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and Sudarsana Kalluru. 27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic Sowa. 28) Support ipv6 geneve tunnels, from John W Linville. 29) Add flood control support to switchdev layer, from Ido Schimmel. 30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from Hannes Frederic Sowa. 31) Support persistent maps and progs in bpf, from Daniel Borkmann. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits) sh_eth: use DMA barriers switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion net: sched: kill dead code in sch_choke.c irda: Delete an unnecessary check before the function call "irlmp_unregister_service" net: dsa: mv88e6xxx: include DSA ports in VLANs net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports net/core: fix for_each_netdev_feature vlan: Invoke driver vlan hooks only if device is present arcnet/com20020: add LEDS_CLASS dependency bpf, verifier: annotate verbose printer with __printf dp83640: Only wait for timestamps for packets with timestamping enabled. ptp: Change ptp_class to a proper bitmask dp83640: Prune rx timestamp list before reading from it dp83640: Delay scheduled work. dp83640: Include hash in timestamp/packet matching ipv6: fix tunnel error handling net/mlx5e: Fix LSO vlan insertion net/mlx5e: Re-eanble client vlan TX acceleration net/mlx5e: Return error in case mlx5e_set_features() fails net/mlx5e: Don't allow more than max supported channels ...
Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c116
1 files changed, 102 insertions, 14 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b074b23000d6..c6073056badf 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -199,6 +199,7 @@ struct verifier_env {
struct verifier_state_list **explored_states; /* search pruning optimization */
struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */
u32 used_map_cnt; /* number of used maps */
+ bool allow_ptr_leaks;
};
/* verbose verifier prints what it's seeing
@@ -213,7 +214,7 @@ static DEFINE_MUTEX(bpf_verifier_lock);
* verbose() is used to dump the verification trace to the log, so the user
* can figure out what's wrong with the program
*/
-static void verbose(const char *fmt, ...)
+static __printf(1, 2) void verbose(const char *fmt, ...)
{
va_list args;
@@ -244,6 +245,7 @@ static const struct {
} func_limit[] = {
{BPF_MAP_TYPE_PROG_ARRAY, BPF_FUNC_tail_call},
{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_read},
+ {BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_output},
};
static void print_verifier_state(struct verifier_env *env)
@@ -538,6 +540,21 @@ static int bpf_size_to_bytes(int bpf_size)
return -EINVAL;
}
+static bool is_spillable_regtype(enum bpf_reg_type type)
+{
+ switch (type) {
+ case PTR_TO_MAP_VALUE:
+ case PTR_TO_MAP_VALUE_OR_NULL:
+ case PTR_TO_STACK:
+ case PTR_TO_CTX:
+ case FRAME_PTR:
+ case CONST_PTR_TO_MAP:
+ return true;
+ default:
+ return false;
+ }
+}
+
/* check_stack_read/write functions track spill/fill of registers,
* stack boundary and alignment are checked in check_mem_access()
*/
@@ -550,9 +567,7 @@ static int check_stack_write(struct verifier_state *state, int off, int size,
*/
if (value_regno >= 0 &&
- (state->regs[value_regno].type == PTR_TO_MAP_VALUE ||
- state->regs[value_regno].type == PTR_TO_STACK ||
- state->regs[value_regno].type == PTR_TO_CTX)) {
+ is_spillable_regtype(state->regs[value_regno].type)) {
/* register containing pointer is being spilled into stack */
if (size != BPF_REG_SIZE) {
@@ -643,6 +658,20 @@ static int check_ctx_access(struct verifier_env *env, int off, int size,
return -EACCES;
}
+static bool is_pointer_value(struct verifier_env *env, int regno)
+{
+ if (env->allow_ptr_leaks)
+ return false;
+
+ switch (env->cur_state.regs[regno].type) {
+ case UNKNOWN_VALUE:
+ case CONST_IMM:
+ return false;
+ default:
+ return true;
+ }
+}
+
/* check whether memory at (regno + off) is accessible for t = (read | write)
* if t==write, value_regno is a register which value is stored into memory
* if t==read, value_regno is a register which will receive the value from memory
@@ -669,11 +698,21 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off,
}
if (state->regs[regno].type == PTR_TO_MAP_VALUE) {
+ if (t == BPF_WRITE && value_regno >= 0 &&
+ is_pointer_value(env, value_regno)) {
+ verbose("R%d leaks addr into map\n", value_regno);
+ return -EACCES;
+ }
err = check_map_access(env, regno, off, size);
if (!err && t == BPF_READ && value_regno >= 0)
mark_reg_unknown_value(state->regs, value_regno);
} else if (state->regs[regno].type == PTR_TO_CTX) {
+ if (t == BPF_WRITE && value_regno >= 0 &&
+ is_pointer_value(env, value_regno)) {
+ verbose("R%d leaks addr into ctx\n", value_regno);
+ return -EACCES;
+ }
err = check_ctx_access(env, off, size, t);
if (!err && t == BPF_READ && value_regno >= 0)
mark_reg_unknown_value(state->regs, value_regno);
@@ -684,10 +723,17 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off,
verbose("invalid stack off=%d size=%d\n", off, size);
return -EACCES;
}
- if (t == BPF_WRITE)
+ if (t == BPF_WRITE) {
+ if (!env->allow_ptr_leaks &&
+ state->stack_slot_type[MAX_BPF_STACK + off] == STACK_SPILL &&
+ size != BPF_REG_SIZE) {
+ verbose("attempt to corrupt spilled pointer on stack\n");
+ return -EACCES;
+ }
err = check_stack_write(state, off, size, value_regno);
- else
+ } else {
err = check_stack_read(state, off, size, value_regno);
+ }
} else {
verbose("R%d invalid mem access '%s'\n",
regno, reg_type_str[state->regs[regno].type]);
@@ -775,8 +821,13 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
return -EACCES;
}
- if (arg_type == ARG_ANYTHING)
+ if (arg_type == ARG_ANYTHING) {
+ if (is_pointer_value(env, regno)) {
+ verbose("R%d leaks addr into helper function\n", regno);
+ return -EACCES;
+ }
return 0;
+ }
if (arg_type == ARG_PTR_TO_STACK || arg_type == ARG_PTR_TO_MAP_KEY ||
arg_type == ARG_PTR_TO_MAP_VALUE) {
@@ -860,7 +911,7 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id)
* don't allow any other map type to be passed into
* the special func;
*/
- if (bool_map != bool_func)
+ if (bool_func && bool_map != bool_func)
return -EINVAL;
}
@@ -950,8 +1001,9 @@ static int check_call(struct verifier_env *env, int func_id)
}
/* check validity of 32-bit and 64-bit arithmetic operations */
-static int check_alu_op(struct reg_state *regs, struct bpf_insn *insn)
+static int check_alu_op(struct verifier_env *env, struct bpf_insn *insn)
{
+ struct reg_state *regs = env->cur_state.regs;
u8 opcode = BPF_OP(insn->code);
int err;
@@ -976,6 +1028,12 @@ static int check_alu_op(struct reg_state *regs, struct bpf_insn *insn)
if (err)
return err;
+ if (is_pointer_value(env, insn->dst_reg)) {
+ verbose("R%d pointer arithmetic prohibited\n",
+ insn->dst_reg);
+ return -EACCES;
+ }
+
/* check dest operand */
err = check_reg_arg(regs, insn->dst_reg, DST_OP);
if (err)
@@ -1012,6 +1070,11 @@ static int check_alu_op(struct reg_state *regs, struct bpf_insn *insn)
*/
regs[insn->dst_reg] = regs[insn->src_reg];
} else {
+ if (is_pointer_value(env, insn->src_reg)) {
+ verbose("R%d partial copy of pointer\n",
+ insn->src_reg);
+ return -EACCES;
+ }
regs[insn->dst_reg].type = UNKNOWN_VALUE;
regs[insn->dst_reg].map_ptr = NULL;
}
@@ -1061,8 +1124,18 @@ static int check_alu_op(struct reg_state *regs, struct bpf_insn *insn)
/* pattern match 'bpf_add Rx, imm' instruction */
if (opcode == BPF_ADD && BPF_CLASS(insn->code) == BPF_ALU64 &&
regs[insn->dst_reg].type == FRAME_PTR &&
- BPF_SRC(insn->code) == BPF_K)
+ BPF_SRC(insn->code) == BPF_K) {
stack_relative = true;
+ } else if (is_pointer_value(env, insn->dst_reg)) {
+ verbose("R%d pointer arithmetic prohibited\n",
+ insn->dst_reg);
+ return -EACCES;
+ } else if (BPF_SRC(insn->code) == BPF_X &&
+ is_pointer_value(env, insn->src_reg)) {
+ verbose("R%d pointer arithmetic prohibited\n",
+ insn->src_reg);
+ return -EACCES;
+ }
/* check dest operand */
err = check_reg_arg(regs, insn->dst_reg, DST_OP);
@@ -1101,6 +1174,12 @@ static int check_cond_jmp_op(struct verifier_env *env,
err = check_reg_arg(regs, insn->src_reg, SRC_OP);
if (err)
return err;
+
+ if (is_pointer_value(env, insn->src_reg)) {
+ verbose("R%d pointer comparison prohibited\n",
+ insn->src_reg);
+ return -EACCES;
+ }
} else {
if (insn->src_reg != BPF_REG_0) {
verbose("BPF_JMP uses reserved fields\n");
@@ -1155,6 +1234,9 @@ static int check_cond_jmp_op(struct verifier_env *env,
regs[insn->dst_reg].type = CONST_IMM;
regs[insn->dst_reg].imm = 0;
}
+ } else if (is_pointer_value(env, insn->dst_reg)) {
+ verbose("R%d pointer comparison prohibited\n", insn->dst_reg);
+ return -EACCES;
} else if (BPF_SRC(insn->code) == BPF_K &&
(opcode == BPF_JEQ || opcode == BPF_JNE)) {
@@ -1658,7 +1740,7 @@ static int do_check(struct verifier_env *env)
}
if (class == BPF_ALU || class == BPF_ALU64) {
- err = check_alu_op(regs, insn);
+ err = check_alu_op(env, insn);
if (err)
return err;
@@ -1816,6 +1898,11 @@ static int do_check(struct verifier_env *env)
if (err)
return err;
+ if (is_pointer_value(env, BPF_REG_0)) {
+ verbose("R0 leaks addr as return value\n");
+ return -EACCES;
+ }
+
process_bpf_exit:
insn_idx = pop_stack(env, &prev_insn_idx);
if (insn_idx < 0) {
@@ -1902,8 +1989,7 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env)
}
f = fdget(insn->imm);
-
- map = bpf_map_get(f);
+ map = __bpf_map_get(f);
if (IS_ERR(map)) {
verbose("fd %d is not pointing to valid bpf_map\n",
insn->imm);
@@ -2024,7 +2110,7 @@ static int convert_ctx_accesses(struct verifier_env *env)
cnt = env->prog->aux->ops->
convert_ctx_access(type, insn->dst_reg, insn->src_reg,
- insn->off, insn_buf);
+ insn->off, insn_buf, env->prog);
if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf)) {
verbose("bpf verifier is misconfigured\n");
return -EINVAL;
@@ -2144,6 +2230,8 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
if (ret < 0)
goto skip_full_check;
+ env->allow_ptr_leaks = capable(CAP_SYS_ADMIN);
+
ret = do_check(env);
skip_full_check: