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-rw-r--r--kernel/bpf/verifier.c525
1 files changed, 312 insertions, 213 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 757476c91c98..be38bb930bf1 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -47,7 +47,7 @@ static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
* - unreachable insns exist (shouldn't be a forest. program = one function)
* - out of bounds or malformed jumps
* The second pass is all possible path descent from the 1st insn.
- * Since it's analyzing all pathes through the program, the length of the
+ * Since it's analyzing all paths through the program, the length of the
* analysis is limited to 64k insn, which may be hit even if total number of
* insn is less then 4K, but there are too many branches that change stack/regs.
* Number of 'branches to be analyzed' is limited to 1k
@@ -132,7 +132,7 @@ static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
* If it's ok, then verifier allows this BPF_CALL insn and looks at
* .ret_type which is RET_PTR_TO_MAP_VALUE_OR_NULL, so it sets
* R0->type = PTR_TO_MAP_VALUE_OR_NULL which means bpf_map_lookup_elem() function
- * returns ether pointer to map value or NULL.
+ * returns either pointer to map value or NULL.
*
* When type PTR_TO_MAP_VALUE_OR_NULL passes through 'if (reg != 0) goto +off'
* insn, the register holding that pointer in the true branch changes state to
@@ -737,81 +737,104 @@ static void print_verifier_state(struct bpf_verifier_env *env,
verbose(env, "\n");
}
-#define COPY_STATE_FN(NAME, COUNT, FIELD, SIZE) \
-static int copy_##NAME##_state(struct bpf_func_state *dst, \
- const struct bpf_func_state *src) \
-{ \
- if (!src->FIELD) \
- return 0; \
- if (WARN_ON_ONCE(dst->COUNT < src->COUNT)) { \
- /* internal bug, make state invalid to reject the program */ \
- memset(dst, 0, sizeof(*dst)); \
- return -EFAULT; \
- } \
- memcpy(dst->FIELD, src->FIELD, \
- sizeof(*src->FIELD) * (src->COUNT / SIZE)); \
- return 0; \
-}
-/* copy_reference_state() */
-COPY_STATE_FN(reference, acquired_refs, refs, 1)
-/* copy_stack_state() */
-COPY_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
-#undef COPY_STATE_FN
-
-#define REALLOC_STATE_FN(NAME, COUNT, FIELD, SIZE) \
-static int realloc_##NAME##_state(struct bpf_func_state *state, int size, \
- bool copy_old) \
-{ \
- u32 old_size = state->COUNT; \
- struct bpf_##NAME##_state *new_##FIELD; \
- int slot = size / SIZE; \
- \
- if (size <= old_size || !size) { \
- if (copy_old) \
- return 0; \
- state->COUNT = slot * SIZE; \
- if (!size && old_size) { \
- kfree(state->FIELD); \
- state->FIELD = NULL; \
- } \
- return 0; \
- } \
- new_##FIELD = kmalloc_array(slot, sizeof(struct bpf_##NAME##_state), \
- GFP_KERNEL); \
- if (!new_##FIELD) \
- return -ENOMEM; \
- if (copy_old) { \
- if (state->FIELD) \
- memcpy(new_##FIELD, state->FIELD, \
- sizeof(*new_##FIELD) * (old_size / SIZE)); \
- memset(new_##FIELD + old_size / SIZE, 0, \
- sizeof(*new_##FIELD) * (size - old_size) / SIZE); \
- } \
- state->COUNT = slot * SIZE; \
- kfree(state->FIELD); \
- state->FIELD = new_##FIELD; \
- return 0; \
-}
-/* realloc_reference_state() */
-REALLOC_STATE_FN(reference, acquired_refs, refs, 1)
-/* realloc_stack_state() */
-REALLOC_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
-#undef REALLOC_STATE_FN
-
-/* do_check() starts with zero-sized stack in struct bpf_verifier_state to
- * make it consume minimal amount of memory. check_stack_write() access from
- * the program calls into realloc_func_state() to grow the stack size.
- * Note there is a non-zero 'parent' pointer inside bpf_verifier_state
- * which realloc_stack_state() copies over. It points to previous
- * bpf_verifier_state which is never reallocated.
+/* copy array src of length n * size bytes to dst. dst is reallocated if it's too
+ * small to hold src. This is different from krealloc since we don't want to preserve
+ * the contents of dst.
+ *
+ * Leaves dst untouched if src is NULL or length is zero. Returns NULL if memory could
+ * not be allocated.
*/
-static int realloc_func_state(struct bpf_func_state *state, int stack_size,
- int refs_size, bool copy_old)
+static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t flags)
{
- int err = realloc_reference_state(state, refs_size, copy_old);
- if (err)
- return err;
- return realloc_stack_state(state, stack_size, copy_old);
+ size_t bytes;
+
+ if (ZERO_OR_NULL_PTR(src))
+ goto out;
+
+ if (unlikely(check_mul_overflow(n, size, &bytes)))
+ return NULL;
+
+ if (ksize(dst) < bytes) {
+ kfree(dst);
+ dst = kmalloc_track_caller(bytes, flags);
+ if (!dst)
+ return NULL;
+ }
+
+ memcpy(dst, src, bytes);
+out:
+ return dst ? dst : ZERO_SIZE_PTR;
+}
+
+/* resize an array from old_n items to new_n items. the array is reallocated if it's too
+ * small to hold new_n items. new items are zeroed out if the array grows.
+ *
+ * Contrary to krealloc_array, does not free arr if new_n is zero.
+ */
+static void *realloc_array(void *arr, size_t old_n, size_t new_n, size_t size)
+{
+ if (!new_n || old_n == new_n)
+ goto out;
+
+ arr = krealloc_array(arr, new_n, size, GFP_KERNEL);
+ if (!arr)
+ return NULL;
+
+ if (new_n > old_n)
+ memset(arr + old_n * size, 0, (new_n - old_n) * size);
+
+out:
+ return arr ? arr : ZERO_SIZE_PTR;
+}
+
+static int copy_reference_state(struct bpf_func_state *dst, const struct bpf_func_state *src)
+{
+ dst->refs = copy_array(dst->refs, src->refs, src->acquired_refs,
+ sizeof(struct bpf_reference_state), GFP_KERNEL);
+ if (!dst->refs)
+ return -ENOMEM;
+
+ dst->acquired_refs = src->acquired_refs;
+ return 0;
+}
+
+static int copy_stack_state(struct bpf_func_state *dst, const struct bpf_func_state *src)
+{
+ size_t n = src->allocated_stack / BPF_REG_SIZE;
+
+ dst->stack = copy_array(dst->stack, src->stack, n, sizeof(struct bpf_stack_state),
+ GFP_KERNEL);
+ if (!dst->stack)
+ return -ENOMEM;
+
+ dst->allocated_stack = src->allocated_stack;
+ return 0;
+}
+
+static int resize_reference_state(struct bpf_func_state *state, size_t n)
+{
+ state->refs = realloc_array(state->refs, state->acquired_refs, n,
+ sizeof(struct bpf_reference_state));
+ if (!state->refs)
+ return -ENOMEM;
+
+ state->acquired_refs = n;
+ return 0;
+}
+
+static int grow_stack_state(struct bpf_func_state *state, int size)
+{
+ size_t old_n = state->allocated_stack / BPF_REG_SIZE, n = size / BPF_REG_SIZE;
+
+ if (old_n >= n)
+ return 0;
+
+ state->stack = realloc_array(state->stack, old_n, n, sizeof(struct bpf_stack_state));
+ if (!state->stack)
+ return -ENOMEM;
+
+ state->allocated_stack = size;
+ return 0;
}
/* Acquire a pointer id from the env and update the state->refs to include
@@ -825,7 +848,7 @@ static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx)
int new_ofs = state->acquired_refs;
int id, err;
- err = realloc_reference_state(state, state->acquired_refs + 1, true);
+ err = resize_reference_state(state, state->acquired_refs + 1);
if (err)
return err;
id = ++env->id_gen;
@@ -854,18 +877,6 @@ static int release_reference_state(struct bpf_func_state *state, int ptr_id)
return -EINVAL;
}
-static int transfer_reference_state(struct bpf_func_state *dst,
- struct bpf_func_state *src)
-{
- int err = realloc_reference_state(dst, src->acquired_refs, false);
- if (err)
- return err;
- err = copy_reference_state(dst, src);
- if (err)
- return err;
- return 0;
-}
-
static void free_func_state(struct bpf_func_state *state)
{
if (!state)
@@ -904,10 +915,6 @@ static int copy_func_state(struct bpf_func_state *dst,
{
int err;
- err = realloc_func_state(dst, src->allocated_stack, src->acquired_refs,
- false);
- if (err)
- return err;
memcpy(dst, src, offsetof(struct bpf_func_state, acquired_refs));
err = copy_reference_state(dst, src);
if (err)
@@ -919,16 +926,13 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
const struct bpf_verifier_state *src)
{
struct bpf_func_state *dst;
- u32 jmp_sz = sizeof(struct bpf_idx_pair) * src->jmp_history_cnt;
int i, err;
- if (dst_state->jmp_history_cnt < src->jmp_history_cnt) {
- kfree(dst_state->jmp_history);
- dst_state->jmp_history = kmalloc(jmp_sz, GFP_USER);
- if (!dst_state->jmp_history)
- return -ENOMEM;
- }
- memcpy(dst_state->jmp_history, src->jmp_history, jmp_sz);
+ dst_state->jmp_history = copy_array(dst_state->jmp_history, src->jmp_history,
+ src->jmp_history_cnt, sizeof(struct bpf_idx_pair),
+ GFP_USER);
+ if (!dst_state->jmp_history)
+ return -ENOMEM;
dst_state->jmp_history_cnt = src->jmp_history_cnt;
/* if dst has more stack frames then src frame, free them */
@@ -2590,8 +2594,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
u32 dst_reg = env->prog->insnsi[insn_idx].dst_reg;
struct bpf_reg_state *reg = NULL;
- err = realloc_func_state(state, round_up(slot + 1, BPF_REG_SIZE),
- state->acquired_refs, true);
+ err = grow_stack_state(state, round_up(slot + 1, BPF_REG_SIZE));
if (err)
return err;
/* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0,
@@ -2613,7 +2616,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
if (dst_reg != BPF_REG_FP) {
/* The backtracking logic can only recognize explicit
* stack slot address like [fp - 8]. Other spill of
- * scalar via different register has to be conervative.
+ * scalar via different register has to be conservative.
* Backtrack from here and mark all registers as precise
* that contributed into 'reg' being a constant.
*/
@@ -2753,8 +2756,7 @@ static int check_stack_write_var_off(struct bpf_verifier_env *env,
if (value_reg && register_is_null(value_reg))
writing_zero = true;
- err = realloc_func_state(state, round_up(-min_off, BPF_REG_SIZE),
- state->acquired_refs, true);
+ err = grow_stack_state(state, round_up(-min_off, BPF_REG_SIZE));
if (err)
return err;
@@ -5629,7 +5631,7 @@ static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn
subprog /* subprog number within this prog */);
/* Transfer references to the callee */
- err = transfer_reference_state(callee, caller);
+ err = copy_reference_state(callee, caller);
if (err)
return err;
@@ -5780,7 +5782,7 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
}
/* Transfer references to the caller */
- err = transfer_reference_state(caller, callee);
+ err = copy_reference_state(caller, callee);
if (err)
return err;
@@ -6409,18 +6411,10 @@ enum {
};
static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg,
- const struct bpf_reg_state *off_reg,
- u32 *alu_limit, u8 opcode)
+ u32 *alu_limit, bool mask_to_left)
{
- bool off_is_neg = off_reg->smin_value < 0;
- bool mask_to_left = (opcode == BPF_ADD && off_is_neg) ||
- (opcode == BPF_SUB && !off_is_neg);
u32 max = 0, ptr_limit = 0;
- if (!tnum_is_const(off_reg->var_off) &&
- (off_reg->smin_value < 0) != (off_reg->smax_value < 0))
- return REASON_BOUNDS;
-
switch (ptr_reg->type) {
case PTR_TO_STACK:
/* Offset 0 is out-of-bounds, but acceptable start for the
@@ -6486,15 +6480,41 @@ static bool sanitize_needed(u8 opcode)
return opcode == BPF_ADD || opcode == BPF_SUB;
}
+struct bpf_sanitize_info {
+ struct bpf_insn_aux_data aux;
+ bool mask_to_left;
+};
+
+static struct bpf_verifier_state *
+sanitize_speculative_path(struct bpf_verifier_env *env,
+ const struct bpf_insn *insn,
+ u32 next_idx, u32 curr_idx)
+{
+ struct bpf_verifier_state *branch;
+ struct bpf_reg_state *regs;
+
+ branch = push_stack(env, next_idx, curr_idx, true);
+ if (branch && insn) {
+ regs = branch->frame[branch->curframe]->regs;
+ if (BPF_SRC(insn->code) == BPF_K) {
+ mark_reg_unknown(env, regs, insn->dst_reg);
+ } else if (BPF_SRC(insn->code) == BPF_X) {
+ mark_reg_unknown(env, regs, insn->dst_reg);
+ mark_reg_unknown(env, regs, insn->src_reg);
+ }
+ }
+ return branch;
+}
+
static int sanitize_ptr_alu(struct bpf_verifier_env *env,
struct bpf_insn *insn,
const struct bpf_reg_state *ptr_reg,
const struct bpf_reg_state *off_reg,
struct bpf_reg_state *dst_reg,
- struct bpf_insn_aux_data *tmp_aux,
+ struct bpf_sanitize_info *info,
const bool commit_window)
{
- struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : tmp_aux;
+ struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : &info->aux;
struct bpf_verifier_state *vstate = env->cur_state;
bool off_is_imm = tnum_is_const(off_reg->var_off);
bool off_is_neg = off_reg->smin_value < 0;
@@ -6515,7 +6535,16 @@ static int sanitize_ptr_alu(struct bpf_verifier_env *env,
if (vstate->speculative)
goto do_sim;
- err = retrieve_ptr_limit(ptr_reg, off_reg, &alu_limit, opcode);
+ if (!commit_window) {
+ if (!tnum_is_const(off_reg->var_off) &&
+ (off_reg->smin_value < 0) != (off_reg->smax_value < 0))
+ return REASON_BOUNDS;
+
+ info->mask_to_left = (opcode == BPF_ADD && off_is_neg) ||
+ (opcode == BPF_SUB && !off_is_neg);
+ }
+
+ err = retrieve_ptr_limit(ptr_reg, &alu_limit, info->mask_to_left);
if (err < 0)
return err;
@@ -6523,8 +6552,8 @@ static int sanitize_ptr_alu(struct bpf_verifier_env *env,
/* In commit phase we narrow the masking window based on
* the observed pointer move after the simulated operation.
*/
- alu_state = tmp_aux->alu_state;
- alu_limit = abs(tmp_aux->alu_limit - alu_limit);
+ alu_state = info->aux.alu_state;
+ alu_limit = abs(info->aux.alu_limit - alu_limit);
} else {
alu_state = off_is_neg ? BPF_ALU_NEG_VALUE : 0;
alu_state |= off_is_imm ? BPF_ALU_IMMEDIATE : 0;
@@ -6539,8 +6568,12 @@ do_sim:
/* If we're in commit phase, we're done here given we already
* pushed the truncated dst_reg into the speculative verification
* stack.
+ *
+ * Also, when register is a known constant, we rewrite register-based
+ * operation to immediate-based, and thus do not need masking (and as
+ * a consequence, do not need to simulate the zero-truncation either).
*/
- if (commit_window)
+ if (commit_window || off_is_imm)
return 0;
/* Simulate and find potential out-of-bounds access under
@@ -6556,12 +6589,26 @@ do_sim:
tmp = *dst_reg;
*dst_reg = *ptr_reg;
}
- ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true);
+ ret = sanitize_speculative_path(env, NULL, env->insn_idx + 1,
+ env->insn_idx);
if (!ptr_is_dst_reg && ret)
*dst_reg = tmp;
return !ret ? REASON_STACK : 0;
}
+static void sanitize_mark_insn_seen(struct bpf_verifier_env *env)
+{
+ struct bpf_verifier_state *vstate = env->cur_state;
+
+ /* If we simulate paths under speculation, we don't update the
+ * insn as 'seen' such that when we verify unreachable paths in
+ * the non-speculative domain, sanitize_dead_code() can still
+ * rewrite/sanitize them.
+ */
+ if (!vstate->speculative)
+ env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+}
+
static int sanitize_err(struct bpf_verifier_env *env,
const struct bpf_insn *insn, int reason,
const struct bpf_reg_state *off_reg,
@@ -6685,7 +6732,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
smin_ptr = ptr_reg->smin_value, smax_ptr = ptr_reg->smax_value;
u64 umin_val = off_reg->umin_value, umax_val = off_reg->umax_value,
umin_ptr = ptr_reg->umin_value, umax_ptr = ptr_reg->umax_value;
- struct bpf_insn_aux_data tmp_aux = {};
+ struct bpf_sanitize_info info = {};
u8 opcode = BPF_OP(insn->code);
u32 dst = insn->dst_reg;
int ret;
@@ -6754,7 +6801,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
if (sanitize_needed(opcode)) {
ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg,
- &tmp_aux, false);
+ &info, false);
if (ret < 0)
return sanitize_err(env, insn, ret, off_reg, dst_reg);
}
@@ -6895,7 +6942,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
return -EACCES;
if (sanitize_needed(opcode)) {
ret = sanitize_ptr_alu(env, insn, dst_reg, off_reg, dst_reg,
- &tmp_aux, true);
+ &info, true);
if (ret < 0)
return sanitize_err(env, insn, ret, off_reg, dst_reg);
}
@@ -7084,11 +7131,10 @@ static void scalar32_min_max_and(struct bpf_reg_state *dst_reg,
s32 smin_val = src_reg->s32_min_value;
u32 umax_val = src_reg->u32_max_value;
- /* Assuming scalar64_min_max_and will be called so its safe
- * to skip updating register for known 32-bit case.
- */
- if (src_known && dst_known)
+ if (src_known && dst_known) {
+ __mark_reg32_known(dst_reg, var32_off.value);
return;
+ }
/* We get our minimum from the var_off, since that's inherently
* bitwise. Our maximum is the minimum of the operands' maxima.
@@ -7108,7 +7154,6 @@ static void scalar32_min_max_and(struct bpf_reg_state *dst_reg,
dst_reg->s32_min_value = dst_reg->u32_min_value;
dst_reg->s32_max_value = dst_reg->u32_max_value;
}
-
}
static void scalar_min_max_and(struct bpf_reg_state *dst_reg,
@@ -7155,11 +7200,10 @@ static void scalar32_min_max_or(struct bpf_reg_state *dst_reg,
s32 smin_val = src_reg->s32_min_value;
u32 umin_val = src_reg->u32_min_value;
- /* Assuming scalar64_min_max_or will be called so it is safe
- * to skip updating register for known case.
- */
- if (src_known && dst_known)
+ if (src_known && dst_known) {
+ __mark_reg32_known(dst_reg, var32_off.value);
return;
+ }
/* We get our maximum from the var_off, and our minimum is the
* maximum of the operands' minima
@@ -7224,11 +7268,10 @@ static void scalar32_min_max_xor(struct bpf_reg_state *dst_reg,
struct tnum var32_off = tnum_subreg(dst_reg->var_off);
s32 smin_val = src_reg->s32_min_value;
- /* Assuming scalar64_min_max_xor will be called so it is safe
- * to skip updating register for known case.
- */
- if (src_known && dst_known)
+ if (src_known && dst_known) {
+ __mark_reg32_known(dst_reg, var32_off.value);
return;
+ }
/* We get both minimum and maximum from the var32_off. */
dst_reg->u32_min_value = var32_off.value;
@@ -8744,14 +8787,28 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
if (err)
return err;
}
+
if (pred == 1) {
- /* only follow the goto, ignore fall-through */
+ /* Only follow the goto, ignore fall-through. If needed, push
+ * the fall-through branch for simulation under speculative
+ * execution.
+ */
+ if (!env->bypass_spec_v1 &&
+ !sanitize_speculative_path(env, insn, *insn_idx + 1,
+ *insn_idx))
+ return -EFAULT;
*insn_idx += insn->off;
return 0;
} else if (pred == 0) {
- /* only follow fall-through branch, since
- * that's where the program will go
+ /* Only follow the fall-through branch, since that's where the
+ * program will go. If needed, push the goto branch for
+ * simulation under speculative execution.
*/
+ if (!env->bypass_spec_v1 &&
+ !sanitize_speculative_path(env, insn,
+ *insn_idx + insn->off + 1,
+ *insn_idx))
+ return -EFAULT;
return 0;
}
@@ -8913,12 +8970,14 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
mark_reg_known_zero(env, regs, insn->dst_reg);
dst_reg->map_ptr = map;
- if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
+ if (insn->src_reg == BPF_PSEUDO_MAP_VALUE ||
+ insn->src_reg == BPF_PSEUDO_MAP_IDX_VALUE) {
dst_reg->type = PTR_TO_MAP_VALUE;
dst_reg->off = aux->map_off;
if (map_value_has_spin_lock(map))
dst_reg->id = ++env->id_gen;
- } else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+ } else if (insn->src_reg == BPF_PSEUDO_MAP_FD ||
+ insn->src_reg == BPF_PSEUDO_MAP_IDX) {
dst_reg->type = CONST_PTR_TO_MAP;
} else {
verbose(env, "bpf verifier is misconfigured\n");
@@ -9049,7 +9108,7 @@ static int check_return_code(struct bpf_verifier_env *env)
!prog->aux->attach_func_proto->type)
return 0;
- /* eBPF calling convetion is such that R0 is used
+ /* eBPF calling convention is such that R0 is used
* to return the value from eBPF program.
* Make sure that it's readable at this time
* of bpf_exit, which means that program wrote
@@ -9434,7 +9493,7 @@ static int check_abnormal_return(struct bpf_verifier_env *env)
static int check_btf_func(struct bpf_verifier_env *env,
const union bpf_attr *attr,
- union bpf_attr __user *uattr)
+ bpfptr_t uattr)
{
const struct btf_type *type, *func_proto, *ret_type;
u32 i, nfuncs, urec_size, min_size;
@@ -9443,7 +9502,7 @@ static int check_btf_func(struct bpf_verifier_env *env,
struct bpf_func_info_aux *info_aux = NULL;
struct bpf_prog *prog;
const struct btf *btf;
- void __user *urecord;
+ bpfptr_t urecord;
u32 prev_offset = 0;
bool scalar_return;
int ret = -ENOMEM;
@@ -9471,7 +9530,7 @@ static int check_btf_func(struct bpf_verifier_env *env,
prog = env->prog;
btf = prog->aux->btf;
- urecord = u64_to_user_ptr(attr->func_info);
+ urecord = make_bpfptr(attr->func_info, uattr.is_kernel);
min_size = min_t(u32, krec_size, urec_size);
krecord = kvcalloc(nfuncs, krec_size, GFP_KERNEL | __GFP_NOWARN);
@@ -9489,13 +9548,15 @@ static int check_btf_func(struct bpf_verifier_env *env,
/* set the size kernel expects so loader can zero
* out the rest of the record.
*/
- if (put_user(min_size, &uattr->func_info_rec_size))
+ if (copy_to_bpfptr_offset(uattr,
+ offsetof(union bpf_attr, func_info_rec_size),
+ &min_size, sizeof(min_size)))
ret = -EFAULT;
}
goto err_free;
}
- if (copy_from_user(&krecord[i], urecord, min_size)) {
+ if (copy_from_bpfptr(&krecord[i], urecord, min_size)) {
ret = -EFAULT;
goto err_free;
}
@@ -9547,7 +9608,7 @@ static int check_btf_func(struct bpf_verifier_env *env,
}
prev_offset = krecord[i].insn_off;
- urecord += urec_size;
+ bpfptr_add(&urecord, urec_size);
}
prog->aux->func_info = krecord;
@@ -9579,14 +9640,14 @@ static void adjust_btf_func(struct bpf_verifier_env *env)
static int check_btf_line(struct bpf_verifier_env *env,
const union bpf_attr *attr,
- union bpf_attr __user *uattr)
+ bpfptr_t uattr)
{
u32 i, s, nr_linfo, ncopy, expected_size, rec_size, prev_offset = 0;
struct bpf_subprog_info *sub;
struct bpf_line_info *linfo;
struct bpf_prog *prog;
const struct btf *btf;
- void __user *ulinfo;
+ bpfptr_t ulinfo;
int err;
nr_linfo = attr->line_info_cnt;
@@ -9612,7 +9673,7 @@ static int check_btf_line(struct bpf_verifier_env *env,
s = 0;
sub = env->subprog_info;
- ulinfo = u64_to_user_ptr(attr->line_info);
+ ulinfo = make_bpfptr(attr->line_info, uattr.is_kernel);
expected_size = sizeof(struct bpf_line_info);
ncopy = min_t(u32, expected_size, rec_size);
for (i = 0; i < nr_linfo; i++) {
@@ -9620,14 +9681,15 @@ static int check_btf_line(struct bpf_verifier_env *env,
if (err) {
if (err == -E2BIG) {
verbose(env, "nonzero tailing record in line_info");
- if (put_user(expected_size,
- &uattr->line_info_rec_size))
+ if (copy_to_bpfptr_offset(uattr,
+ offsetof(union bpf_attr, line_info_rec_size),
+ &expected_size, sizeof(expected_size)))
err = -EFAULT;
}
goto err_free;
}
- if (copy_from_user(&linfo[i], ulinfo, ncopy)) {
+ if (copy_from_bpfptr(&linfo[i], ulinfo, ncopy)) {
err = -EFAULT;
goto err_free;
}
@@ -9679,7 +9741,7 @@ static int check_btf_line(struct bpf_verifier_env *env,
}
prev_offset = linfo[i].insn_off;
- ulinfo += rec_size;
+ bpfptr_add(&ulinfo, rec_size);
}
if (s != env->subprog_cnt) {
@@ -9701,7 +9763,7 @@ err_free:
static int check_btf_info(struct bpf_verifier_env *env,
const union bpf_attr *attr,
- union bpf_attr __user *uattr)
+ bpfptr_t uattr)
{
struct btf *btf;
int err;
@@ -9746,13 +9808,6 @@ static bool range_within(struct bpf_reg_state *old,
old->s32_max_value >= cur->s32_max_value;
}
-/* Maximum number of register states that can exist at once */
-#define ID_MAP_SIZE (MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE)
-struct idpair {
- u32 old;
- u32 cur;
-};
-
/* If in the old state two registers had the same id, then they need to have
* the same id in the new state as well. But that id could be different from
* the old state, so we need to track the mapping from old to new ids.
@@ -9763,11 +9818,11 @@ struct idpair {
* So we look through our idmap to see if this old id has been seen before. If
* so, we require the new id to match; otherwise, we add the id pair to the map.
*/
-static bool check_ids(u32 old_id, u32 cur_id, struct idpair *idmap)
+static bool check_ids(u32 old_id, u32 cur_id, struct bpf_id_pair *idmap)
{
unsigned int i;
- for (i = 0; i < ID_MAP_SIZE; i++) {
+ for (i = 0; i < BPF_ID_MAP_SIZE; i++) {
if (!idmap[i].old) {
/* Reached an empty slot; haven't seen this id before */
idmap[i].old = old_id;
@@ -9844,7 +9899,7 @@ static void clean_verifier_state(struct bpf_verifier_env *env,
* Since the verifier pushes the branch states as it sees them while exploring
* the program the condition of walking the branch instruction for the second
* time means that all states below this branch were already explored and
- * their final liveness markes are already propagated.
+ * their final liveness marks are already propagated.
* Hence when the verifier completes the search of state list in is_state_visited()
* we can call this clean_live_states() function to mark all liveness states
* as REG_LIVE_DONE to indicate that 'parent' pointers of 'struct bpf_reg_state'
@@ -9880,7 +9935,7 @@ next:
/* Returns true if (rold safe implies rcur safe) */
static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
- struct idpair *idmap)
+ struct bpf_id_pair *idmap)
{
bool equal;
@@ -9998,7 +10053,7 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
static bool stacksafe(struct bpf_func_state *old,
struct bpf_func_state *cur,
- struct idpair *idmap)
+ struct bpf_id_pair *idmap)
{
int i, spi;
@@ -10095,32 +10150,23 @@ static bool refsafe(struct bpf_func_state *old, struct bpf_func_state *cur)
* whereas register type in current state is meaningful, it means that
* the current state will reach 'bpf_exit' instruction safely
*/
-static bool func_states_equal(struct bpf_func_state *old,
+static bool func_states_equal(struct bpf_verifier_env *env, struct bpf_func_state *old,
struct bpf_func_state *cur)
{
- struct idpair *idmap;
- bool ret = false;
int i;
- idmap = kcalloc(ID_MAP_SIZE, sizeof(struct idpair), GFP_KERNEL);
- /* If we failed to allocate the idmap, just say it's not safe */
- if (!idmap)
- return false;
-
- for (i = 0; i < MAX_BPF_REG; i++) {
- if (!regsafe(&old->regs[i], &cur->regs[i], idmap))
- goto out_free;
- }
+ memset(env->idmap_scratch, 0, sizeof(env->idmap_scratch));
+ for (i = 0; i < MAX_BPF_REG; i++)
+ if (!regsafe(&old->regs[i], &cur->regs[i], env->idmap_scratch))
+ return false;
- if (!stacksafe(old, cur, idmap))
- goto out_free;
+ if (!stacksafe(old, cur, env->idmap_scratch))
+ return false;
if (!refsafe(old, cur))
- goto out_free;
- ret = true;
-out_free:
- kfree(idmap);
- return ret;
+ return false;
+
+ return true;
}
static bool states_equal(struct bpf_verifier_env *env,
@@ -10147,7 +10193,7 @@ static bool states_equal(struct bpf_verifier_env *env,
for (i = 0; i <= old->curframe; i++) {
if (old->frame[i]->callsite != cur->frame[i]->callsite)
return false;
- if (!func_states_equal(old->frame[i], cur->frame[i]))
+ if (!func_states_equal(env, old->frame[i], cur->frame[i]))
return false;
}
return true;
@@ -10624,7 +10670,7 @@ static int do_check(struct bpf_verifier_env *env)
}
regs = cur_regs(env);
- env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+ sanitize_mark_insn_seen(env);
prev_insn_idx = env->insn_idx;
if (class == BPF_ALU || class == BPF_ALU64) {
@@ -10851,7 +10897,7 @@ process_bpf_exit:
return err;
env->insn_idx++;
- env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+ sanitize_mark_insn_seen(env);
} else {
verbose(env, "invalid BPF_LD mode\n");
return -EINVAL;
@@ -11184,6 +11230,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
struct bpf_map *map;
struct fd f;
u64 addr;
+ u32 fd;
if (i == insn_cnt - 1 || insn[1].code != 0 ||
insn[1].dst_reg != 0 || insn[1].src_reg != 0 ||
@@ -11213,16 +11260,38 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
/* In final convert_pseudo_ld_imm64() step, this is
* converted into regular 64-bit imm load insn.
*/
- if ((insn[0].src_reg != BPF_PSEUDO_MAP_FD &&
- insn[0].src_reg != BPF_PSEUDO_MAP_VALUE) ||
- (insn[0].src_reg == BPF_PSEUDO_MAP_FD &&
- insn[1].imm != 0)) {
- verbose(env,
- "unrecognized bpf_ld_imm64 insn\n");
+ switch (insn[0].src_reg) {
+ case BPF_PSEUDO_MAP_VALUE:
+ case BPF_PSEUDO_MAP_IDX_VALUE:
+ break;
+ case BPF_PSEUDO_MAP_FD:
+ case BPF_PSEUDO_MAP_IDX:
+ if (insn[1].imm == 0)
+ break;
+ fallthrough;
+ default:
+ verbose(env, "unrecognized bpf_ld_imm64 insn\n");
return -EINVAL;
}
- f = fdget(insn[0].imm);
+ switch (insn[0].src_reg) {
+ case BPF_PSEUDO_MAP_IDX_VALUE:
+ case BPF_PSEUDO_MAP_IDX:
+ if (bpfptr_is_null(env->fd_array)) {
+ verbose(env, "fd_idx without fd_array is invalid\n");
+ return -EPROTO;
+ }
+ if (copy_from_bpfptr_offset(&fd, env->fd_array,
+ insn[0].imm * sizeof(fd),
+ sizeof(fd)))
+ return -EFAULT;
+ break;
+ default:
+ fd = insn[0].imm;
+ break;
+ }
+
+ f = fdget(fd);
map = __bpf_map_get(f);
if (IS_ERR(map)) {
verbose(env, "fd %d is not pointing to valid bpf_map\n",
@@ -11237,7 +11306,8 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
}
aux = &env->insn_aux_data[i];
- if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+ if (insn[0].src_reg == BPF_PSEUDO_MAP_FD ||
+ insn[0].src_reg == BPF_PSEUDO_MAP_IDX) {
addr = (unsigned long)map;
} else {
u32 off = insn[1].imm;
@@ -11360,6 +11430,7 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env,
{
struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
struct bpf_insn *insn = new_prog->insnsi;
+ u32 old_seen = old_data[off].seen;
u32 prog_len;
int i;
@@ -11380,7 +11451,8 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env,
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 = env->pass_cnt;
+ /* Expand insni[off]'s seen count to the patched range. */
+ new_data[i].seen = old_seen;
new_data[i].zext_dst = insn_has_def32(env, insn + i);
}
env->insn_aux_data = new_data;
@@ -11402,7 +11474,7 @@ static void adjust_subprog_starts(struct bpf_verifier_env *env, u32 off, u32 len
}
}
-static void adjust_poke_descs(struct bpf_prog *prog, u32 len)
+static void adjust_poke_descs(struct bpf_prog *prog, u32 off, u32 len)
{
struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
int i, sz = prog->aux->size_poke_tab;
@@ -11410,6 +11482,8 @@ static void adjust_poke_descs(struct bpf_prog *prog, u32 len)
for (i = 0; i < sz; i++) {
desc = &tab[i];
+ if (desc->insn_idx <= off)
+ continue;
desc->insn_idx += len - 1;
}
}
@@ -11430,7 +11504,7 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
if (adjust_insn_aux_data(env, new_prog, off, len))
return NULL;
adjust_subprog_starts(env, off, len);
- adjust_poke_descs(new_prog, len);
+ adjust_poke_descs(new_prog, off, len);
return new_prog;
}
@@ -12449,7 +12523,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
prog->aux->max_pkt_offset = MAX_PACKET_OFF;
/* mark bpf_tail_call as different opcode to avoid
- * conditional branch in the interpeter for every normal
+ * conditional branch in the interpreter for every normal
* call and to prevent accidental JITing by JIT compiler
* that doesn't support bpf_tail_call yet
*/
@@ -12704,6 +12778,9 @@ static void free_states(struct bpf_verifier_env *env)
* insn_aux_data was touched. These variables are compared to clear temporary
* data from failed pass. For testing and experiments do_check_common() can be
* run multiple times even when prior attempt to verify is unsuccessful.
+ *
+ * Note that special handling is needed on !env->bypass_spec_v1 if this is
+ * ever called outside of error path with subsequent program rejection.
*/
static void sanitize_insn_aux_data(struct bpf_verifier_env *env)
{
@@ -13200,6 +13277,17 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
return 0;
}
+BTF_SET_START(btf_id_deny)
+BTF_ID_UNUSED
+#ifdef CONFIG_SMP
+BTF_ID(func, migrate_disable)
+BTF_ID(func, migrate_enable)
+#endif
+#if !defined CONFIG_PREEMPT_RCU && !defined CONFIG_TINY_RCU
+BTF_ID(func, rcu_read_unlock_strict)
+#endif
+BTF_SET_END(btf_id_deny)
+
static int check_attach_btf_id(struct bpf_verifier_env *env)
{
struct bpf_prog *prog = env->prog;
@@ -13210,6 +13298,14 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
int ret;
u64 key;
+ if (prog->type == BPF_PROG_TYPE_SYSCALL) {
+ if (prog->aux->sleepable)
+ /* attach_btf_id checked to be zero already */
+ return 0;
+ verbose(env, "Syscall programs can only be sleepable\n");
+ return -EINVAL;
+ }
+
if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING &&
prog->type != BPF_PROG_TYPE_LSM) {
verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n");
@@ -13259,6 +13355,9 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
ret = bpf_lsm_verify_prog(&env->log, prog);
if (ret < 0)
return ret;
+ } else if (prog->type == BPF_PROG_TYPE_TRACING &&
+ btf_id_set_contains(&btf_id_deny, btf_id)) {
+ return -EINVAL;
}
key = bpf_trampoline_compute_key(tgt_prog, prog->aux->attach_btf, btf_id);
@@ -13281,8 +13380,7 @@ struct btf *bpf_get_btf_vmlinux(void)
return btf_vmlinux;
}
-int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
- union bpf_attr __user *uattr)
+int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr)
{
u64 start_time = ktime_get_ns();
struct bpf_verifier_env *env;
@@ -13312,6 +13410,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
env->insn_aux_data[i].orig_idx = i;
env->prog = *prog;
env->ops = bpf_verifier_ops[env->prog->type];
+ env->fd_array = make_bpfptr(attr->fd_array, uattr.is_kernel);
is_priv = bpf_capable();
bpf_get_btf_vmlinux();
@@ -13358,12 +13457,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (is_priv)
env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
- if (bpf_prog_is_dev_bound(env->prog->aux)) {
- ret = bpf_prog_offload_verifier_prep(env->prog);
- if (ret)
- goto skip_full_check;
- }
-
env->explored_states = kvcalloc(state_htab_size(env),
sizeof(struct bpf_verifier_state_list *),
GFP_USER);
@@ -13391,6 +13484,12 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (ret < 0)
goto skip_full_check;
+ if (bpf_prog_is_dev_bound(env->prog->aux)) {
+ ret = bpf_prog_offload_verifier_prep(env->prog);
+ if (ret)
+ goto skip_full_check;
+ }
+
ret = check_cfg(env);
if (ret < 0)
goto skip_full_check;