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bpf: fix verifier memory leaks 

fix verifier memory leaks

Fixes: 638f5b90d4 ("bpf: reduce verifier memory consumption")
Signed-off-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov 2017-11-01 00:08:04 -07:00 committed by David S. Miller
parent 4bfbe53f41
commit 1969db47f8
1 changed files with 18 additions and 9 deletions
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27
kernel/bpf/verifier.c
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@ -341,10 +341,12 @@ static int realloc_verifier_state(struct bpf_verifier_state *state, int size,
return 0;
}
static void free_verifier_state(struct bpf_verifier_state *state)
static void free_verifier_state(struct bpf_verifier_state *state,
bool free_self)
{
kfree(state->stack);
kfree(state);
if (free_self)
kfree(state);
}
/* copy verifier state from src to dst growing dst stack space
@ -382,6 +384,7 @@ static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx,
if (prev_insn_idx)
*prev_insn_idx = head->prev_insn_idx;
elem = head->next;
free_verifier_state(&head->st, false);
kfree(head);
env->head = elem;
env->stack_size--;
@ -399,14 +402,14 @@ static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env,
if (!elem)
goto err;
err = copy_verifier_state(&elem->st, cur);
if (err)
return NULL;
elem->insn_idx = insn_idx;
elem->prev_insn_idx = prev_insn_idx;
elem->next = env->head;
env->head = elem;
env->stack_size++;
err = copy_verifier_state(&elem->st, cur);
if (err)
goto err;
if (env->stack_size > BPF_COMPLEXITY_LIMIT_STACK) {
verbose(env, "BPF program is too complex\n");
goto err;
@ -3641,7 +3644,7 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
struct bpf_verifier_state_list *new_sl;
struct bpf_verifier_state_list *sl;
struct bpf_verifier_state *cur = env->cur_state;
int i;
int i, err;
sl = env->explored_states[insn_idx];
if (!sl)
@ -3679,7 +3682,12 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
return -ENOMEM;
/* add new state to the head of linked list */
copy_verifier_state(&new_sl->state, cur);
err = copy_verifier_state(&new_sl->state, cur);
if (err) {
free_verifier_state(&new_sl->state, false);
kfree(new_sl);
return err;
}
new_sl->next = env->explored_states[insn_idx];
env->explored_states[insn_idx] = new_sl;
/* connect new state to parentage chain */
@ -4424,6 +4432,7 @@ static void free_states(struct bpf_verifier_env *env)
if (sl)
while (sl != STATE_LIST_MARK) {
sln = sl->next;
free_verifier_state(&sl->state, false);
kfree(sl);
sl = sln;
}
@ -4494,7 +4503,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
env->allow_ptr_leaks = capable(CAP_SYS_ADMIN);
ret = do_check(env);
free_verifier_state(env->cur_state);
free_verifier_state(env->cur_state, true);
env->cur_state = NULL;
skip_full_check:
@ -4601,7 +4610,7 @@ int bpf_analyzer(struct bpf_prog *prog, const struct bpf_ext_analyzer_ops *ops,
env->allow_ptr_leaks = capable(CAP_SYS_ADMIN);
ret = do_check(env);
free_verifier_state(env->cur_state);
free_verifier_state(env->cur_state, true);
env->cur_state = NULL;
skip_full_check: