From 9b38c4056b2736bb5902e8b0911832db666fd19b Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 19 Dec 2018 22:13:06 -0800 Subject: [PATCH] bpf: verifier: reorder stack size check with dead code sanitization Reorder the calls to check_max_stack_depth() and sanitize_dead_code() to separate functions which can rewrite instructions from pure checks. No functional changes. Signed-off-by: Jakub Kicinski Reviewed-by: Jiong Wang Signed-off-by: Daniel Borkmann --- kernel/bpf/verifier.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 98ed27bbd045..d27d5a880015 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6982,12 +6982,13 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, while (!pop_stack(env, NULL, NULL)); free_states(env); - if (ret == 0) - sanitize_dead_code(env); - if (ret == 0) ret = check_max_stack_depth(env); + /* instruction rewrites happen after this point */ + if (ret == 0) + sanitize_dead_code(env); + if (ret == 0) /* program is valid, convert *(u32*)(ctx + off) accesses */ ret = convert_ctx_accesses(env);