From 792f23c878fb0000e521ba43aba32d2cafdddd2b Mon Sep 17 00:00:00 2001 From: John Johansen Date: Thu, 18 Jul 2024 06:29:44 -0700 Subject: [PATCH] chfa: get not-flextable size and padding correct The kernel does not expect a name and it is not used even within the parser so drop it. Correct the padding calculation. sizeof(th_version) includes the trailing \0 in the count so we should not be adding it explicitly. Doing so made it seem like we were writing an extra byte and messing things up, because the string write below did not include the \0 which we had to add explicitly. Switch to writing the th_version using size_of() bytes as is used in the pad calculation, to avoid confusion around the header padding. Signed-off-by: John Johansen --- parser/libapparmor_re/aare_rules.cc | 2 +- parser/libapparmor_re/chfa.cc | 9 +++++---- parser/libapparmor_re/chfa.h | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/parser/libapparmor_re/aare_rules.cc b/parser/libapparmor_re/aare_rules.cc index c344117f5..410953cc8 100644 --- a/parser/libapparmor_re/aare_rules.cc +++ b/parser/libapparmor_re/aare_rules.cc @@ -307,7 +307,7 @@ void *aare_rules::create_dfa(size_t *size, int *min_match_len, optflags const &o CHFA chfa(dfa, eq, opts); if (opts.dump & DUMP_DFA_TRANS_TABLE) chfa.dump(cerr); - chfa.flex_table(stream, ""); + chfa.flex_table(stream); } catch(int error) { *size = 0; diff --git a/parser/libapparmor_re/chfa.cc b/parser/libapparmor_re/chfa.cc index 658218958..205c697c2 100644 --- a/parser/libapparmor_re/chfa.cc +++ b/parser/libapparmor_re/chfa.cc @@ -368,7 +368,7 @@ template os << fill64(sizeof(td) + sizeof(*pos) * size); } -void CHFA::flex_table(ostream &os, const char *name) +void CHFA::flex_table(ostream &os) { const char th_version[] = "notflex"; struct table_set_header th = { 0, 0, 0, 0 }; @@ -419,7 +419,8 @@ void CHFA::flex_table(ostream &os, const char *name) /* Write the actual flex parser table. */ /* TODO: add max_oob */ - size_t hsize = pad64(sizeof(th) + sizeof(th_version) + strlen(name) + 1); + // sizeof(th_version) includes trailing \0 + size_t hsize = pad64(sizeof(th) + sizeof(th_version)); th.th_magic = htonl(YYTH_REGEX_MAGIC); th.th_flags = htons(chfaflags); th.th_hsize = htonl(hsize); @@ -432,8 +433,8 @@ void CHFA::flex_table(ostream &os, const char *name) flex_table_size(next_vec.begin(), next_vec.end()) + flex_table_size(check_vec.begin(), check_vec.end())); os.write((char *)&th, sizeof(th)); - os << th_version << (char)0 << name << (char)0; - os << fill64(sizeof(th) + sizeof(th_version) + strlen(name) + 1); + os.write(th_version, sizeof(th_version)); + os << fill64(sizeof(th) + sizeof(th_version)); write_flex_table(os, YYTD_ID_ACCEPT, accept.begin(), accept.end()); write_flex_table(os, YYTD_ID_ACCEPT2, accept2.begin(), accept2.end()); diff --git a/parser/libapparmor_re/chfa.h b/parser/libapparmor_re/chfa.h index 9548080b2..7d6a6f4af 100644 --- a/parser/libapparmor_re/chfa.h +++ b/parser/libapparmor_re/chfa.h @@ -39,7 +39,7 @@ class CHFA { public: CHFA(DFA &dfa, map &eq, optflags const &opts); void dump(ostream & os); - void flex_table(ostream &os, const char *name); + void flex_table(ostream &os); void init_free_list(vector > &free_list, size_t prev, size_t start); bool fits_in(vector > &free_list, size_t base,