From: Alexei Starovoitov ast@fb.com
commit 1969db47f8d0e800397abd4ee4e8d27d2b578587 upstream.
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 Signed-off-by: Balbir Singh sblbir@amzn.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/bpf/verifier.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-)
--- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -491,10 +491,12 @@ 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 @@ -532,6 +534,7 @@ 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--; @@ -549,14 +552,14 @@ 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("BPF program is too complex\n"); goto err; @@ -3812,7 +3815,7 @@ 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) @@ -3850,7 +3853,12 @@ 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 */ @@ -4692,6 +4700,7 @@ 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; } @@ -4768,7 +4777,7 @@ 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: @@ -4878,7 +4887,7 @@ 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: