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Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/offload.c27
-rw-r--r--kernel/bpf/syscall.c40
-rw-r--r--kernel/bpf/verifier.c31
-rw-r--r--kernel/trace/bpf_trace.c12
4 files changed, 59 insertions, 51 deletions
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 2816feb38be1..68ec884440b7 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -14,8 +14,9 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
struct net *net = current->nsproxy->net_ns;
struct bpf_dev_offload *offload;
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
+ if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
+ attr->prog_type != BPF_PROG_TYPE_XDP)
+ return -EINVAL;
if (attr->prog_flags)
return -EINVAL;
@@ -28,7 +29,7 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
init_waitqueue_head(&offload->verifier_done);
rtnl_lock();
- offload->netdev = __dev_get_by_index(net, attr->prog_target_ifindex);
+ offload->netdev = __dev_get_by_index(net, attr->prog_ifindex);
if (!offload->netdev) {
rtnl_unlock();
kfree(offload);
@@ -85,6 +86,10 @@ static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
struct bpf_dev_offload *offload = prog->aux->offload;
struct netdev_bpf data = {};
+ /* Caution - if netdev is destroyed before the program, this function
+ * will be called twice.
+ */
+
data.offload.prog = prog;
if (offload->verifier_running)
@@ -144,18 +149,6 @@ int bpf_prog_offload_compile(struct bpf_prog *prog)
return bpf_prog_offload_translate(prog);
}
-u32 bpf_prog_offload_ifindex(struct bpf_prog *prog)
-{
- struct bpf_dev_offload *offload = prog->aux->offload;
- u32 ifindex;
-
- rtnl_lock();
- ifindex = offload->netdev ? offload->netdev->ifindex : 0;
- rtnl_unlock();
-
- return ifindex;
-}
-
const struct bpf_prog_ops bpf_offload_prog_ops = {
};
@@ -169,6 +162,10 @@ static int bpf_offload_notification(struct notifier_block *notifier,
switch (event) {
case NETDEV_UNREGISTER:
+ /* ignore namespace changes */
+ if (netdev->reg_state != NETREG_UNREGISTERING)
+ break;
+
list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs,
offloads) {
if (offload->netdev == netdev)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 09badc37e864..2c4cfeaa8d5e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1057,22 +1057,23 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
}
EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
-static bool bpf_prog_can_attach(struct bpf_prog *prog,
- enum bpf_prog_type *attach_type,
- struct net_device *netdev)
+static bool bpf_prog_get_ok(struct bpf_prog *prog,
+ enum bpf_prog_type *attach_type, bool attach_drv)
{
- struct bpf_dev_offload *offload = prog->aux->offload;
+ /* not an attachment, just a refcount inc, always allow */
+ if (!attach_type)
+ return true;
if (prog->type != *attach_type)
return false;
- if (offload && offload->netdev != netdev)
+ if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
return false;
return true;
}
static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
- struct net_device *netdev)
+ bool attach_drv)
{
struct fd f = fdget(ufd);
struct bpf_prog *prog;
@@ -1080,7 +1081,7 @@ static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
prog = ____bpf_prog_get(f);
if (IS_ERR(prog))
return prog;
- if (attach_type && !bpf_prog_can_attach(prog, attach_type, netdev)) {
+ if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
prog = ERR_PTR(-EINVAL);
goto out;
}
@@ -1093,23 +1094,13 @@ out:
struct bpf_prog *bpf_prog_get(u32 ufd)
{
- return __bpf_prog_get(ufd, NULL, NULL);
+ return __bpf_prog_get(ufd, NULL, false);
}
-struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
-{
- struct bpf_prog *prog = __bpf_prog_get(ufd, &type, NULL);
-
- if (!IS_ERR(prog))
- trace_bpf_prog_get_type(prog);
- return prog;
-}
-EXPORT_SYMBOL_GPL(bpf_prog_get_type);
-
struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
- struct net_device *netdev)
+ bool attach_drv)
{
- struct bpf_prog *prog = __bpf_prog_get(ufd, &type, netdev);
+ struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
if (!IS_ERR(prog))
trace_bpf_prog_get_type(prog);
@@ -1118,7 +1109,7 @@ struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
/* last field in 'union bpf_attr' used by this command */
-#define BPF_PROG_LOAD_LAST_FIELD prog_target_ifindex
+#define BPF_PROG_LOAD_LAST_FIELD prog_ifindex
static int bpf_prog_load(union bpf_attr *attr)
{
@@ -1181,7 +1172,7 @@ static int bpf_prog_load(union bpf_attr *attr)
atomic_set(&prog->aux->refcnt, 1);
prog->gpl_compatible = is_gpl ? 1 : 0;
- if (attr->prog_target_ifindex) {
+ if (attr->prog_ifindex) {
err = bpf_prog_offload_init(prog, attr);
if (err)
goto free_prog;
@@ -1625,11 +1616,6 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
return -EFAULT;
}
- if (bpf_prog_is_dev_bound(prog->aux)) {
- info.status |= BPF_PROG_STATUS_DEV_BOUND;
- info.ifindex = bpf_prog_offload_ifindex(prog);
- }
-
done:
if (copy_to_user(uinfo, &info, info_len) ||
put_user(info_len, &uattr->info.info_len))
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index dd54d20ace2f..d4593571c404 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1384,13 +1384,15 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
if (type != expected_type)
goto err_type;
} else if (arg_type == ARG_PTR_TO_MEM ||
+ arg_type == ARG_PTR_TO_MEM_OR_NULL ||
arg_type == ARG_PTR_TO_UNINIT_MEM) {
expected_type = PTR_TO_STACK;
/* One exception here. In case function allows for NULL to be
* passed in as argument, it's a SCALAR_VALUE type. Final test
* happens during stack boundary checking.
*/
- if (register_is_null(*reg))
+ if (register_is_null(*reg) &&
+ arg_type == ARG_PTR_TO_MEM_OR_NULL)
/* final test in check_stack_boundary() */;
else if (!type_is_pkt_pointer(type) &&
type != PTR_TO_MAP_VALUE &&
@@ -3825,6 +3827,7 @@ static int do_check(struct bpf_verifier_env *env)
return err;
regs = cur_regs(env);
+ env->insn_aux_data[insn_idx].seen = true;
if (class == BPF_ALU || class == BPF_ALU64) {
err = check_alu_op(env, insn);
if (err)
@@ -4020,6 +4023,7 @@ process_bpf_exit:
return err;
insn_idx++;
+ env->insn_aux_data[insn_idx].seen = true;
} else {
verbose(env, "invalid BPF_LD mode\n");
return -EINVAL;
@@ -4202,6 +4206,7 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len,
u32 off, u32 cnt)
{
struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
+ int i;
if (cnt == 1)
return 0;
@@ -4211,6 +4216,8 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len,
memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off);
memcpy(new_data + off + cnt - 1, old_data + off,
sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
+ for (i = off; i < off + cnt - 1; i++)
+ new_data[i].seen = true;
env->insn_aux_data = new_data;
vfree(old_data);
return 0;
@@ -4229,6 +4236,25 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
return new_prog;
}
+/* The verifier does more data flow analysis than llvm and will not explore
+ * branches that are dead at run time. Malicious programs can have dead code
+ * too. Therefore replace all dead at-run-time code with nops.
+ */
+static void sanitize_dead_code(struct bpf_verifier_env *env)
+{
+ struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+ struct bpf_insn nop = BPF_MOV64_REG(BPF_REG_0, BPF_REG_0);
+ struct bpf_insn *insn = env->prog->insnsi;
+ const int insn_cnt = env->prog->len;
+ int i;
+
+ for (i = 0; i < insn_cnt; i++) {
+ if (aux_data[i].seen)
+ continue;
+ memcpy(insn + i, &nop, sizeof(nop));
+ }
+}
+
/* convert load instructions that access fields of 'struct __sk_buff'
* into sequence of instructions that access fields of 'struct sk_buff'
*/
@@ -4556,6 +4582,9 @@ skip_full_check:
free_states(env);
if (ret == 0)
+ sanitize_dead_code(env);
+
+ if (ret == 0)
/* program is valid, convert *(u32*)(ctx + off) accesses */
ret = convert_ctx_accesses(env);
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index a5580c670866..27d1f4ffa3de 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -78,16 +78,12 @@ EXPORT_SYMBOL_GPL(trace_call_bpf);
BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
{
- int ret = 0;
-
- if (unlikely(size == 0))
- goto out;
+ int ret;
ret = probe_kernel_read(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
memset(dst, 0, size);
- out:
return ret;
}
@@ -407,7 +403,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto = {
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
- .arg5_type = ARG_CONST_SIZE,
+ .arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs);
@@ -498,7 +494,7 @@ static const struct bpf_func_proto bpf_probe_read_str_proto = {
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
- .arg2_type = ARG_CONST_SIZE,
+ .arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
@@ -609,7 +605,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
- .arg5_type = ARG_CONST_SIZE,
+ .arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
generated by cgit (git 2.34.1) at 2024-05-03 01:13:14 +0000