From: Alexei Starovoitov <ast@fb.com>
Date: Wed, 1 Nov 2017 00:08:04 -0700
Subject: bpf: fix verifier memory leaks
Patch-mainline: v4.15-rc1
Git-commit: 1969db47f8d0e800397abd4ee4e8d27d2b578587
References: bsc#1083647
fix verifier memory leaks
Fixes: 638f5b90d460 ("bpf: reduce verifier memory consumption")
Signed-off-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Gary Lin <glin@suse.com>
---
kernel/bpf/verifier.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -334,10 +334,12 @@ static int realloc_verifier_state(struct
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
@@ -375,6 +377,7 @@ static int pop_stack(struct bpf_verifier
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--;
@@ -392,14 +395,14 @@ static struct bpf_verifier_state *push_s
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;
@@ -3502,7 +3505,7 @@ static int is_state_visited(struct bpf_v
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)
@@ -3540,7 +3543,12 @@ static int is_state_visited(struct bpf_v
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 */
@@ -4262,6 +4270,7 @@ static void free_states(struct bpf_verif
if (sl)
while (sl != STATE_LIST_MARK) {
sln = sl->next;
+ free_verifier_state(&sl->state, false);
kfree(sl);
sl = sln;
}
@@ -4332,7 +4341,7 @@ int bpf_check(struct bpf_prog **prog, un
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:
@@ -4439,7 +4448,7 @@ int bpf_analyzer(struct bpf_prog *prog,
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: