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| author | Florian Weimer <fweimer@redhat.com> | 2018-07-10 11:18:26 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2018-07-10 11:18:26 +0200 |
| commit | 7b2f4cedf044ea83f53f6b43a5bf6871eb9ce969 (patch) | |
| tree | 4e579c9471bc1d2d1a799ba005023fc7a7f4440b | |
| parent | 4fa34da6793c442255fc003cf659c85b197ab29a (diff) | |
| download | glibc-7b2f4cedf044ea83f53f6b43a5bf6871eb9ce969.tar.gz glibc-7b2f4cedf044ea83f53f6b43a5bf6871eb9ce969.tar.xz glibc-7b2f4cedf044ea83f53f6b43a5bf6871eb9ce969.zip | |
regexec: Fix off-by-one bug in weight comparison [BZ #23036]
Each weight is prefixed by its length, and the length does not include itself in the count. This can be seen clearly from the find_idx function in string/strxfrm_l.c, for example. The old code behaved as if the length itself counted, thus comparing an additional byte after the weight, leading to spurious comparison failures and incorrect further partitioning of character equivalence classes.
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | posix/regexec.c | 43 |
2 files changed, 27 insertions, 23 deletions
diff --git a/ChangeLog b/ChangeLog index 8068171e2b..d18c24453f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,12 @@ 2018-07-10 Florian Weimer <fweimer@redhat.com> + [BZ #23036] + * posix/regexec.c (check_node_accept_bytes): When comparing + weights, do not compare an extra byte after the end of the + weights. + +2018-07-10 Florian Weimer <fweimer@redhat.com> + * libio/readline.c: Fix copyright year. * libio/tst-readline.c Likewise. * nss/tst-nss-files-hosts-getent.c: Likewise. diff --git a/posix/regexec.c b/posix/regexec.c index 63aef97535..73644c2341 100644 --- a/posix/regexec.c +++ b/posix/regexec.c @@ -3878,30 +3878,27 @@ check_node_accept_bytes (const re_dfa_t *dfa, Idx node_idx, indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_INDIRECTMB); int32_t idx = findidx (table, indirect, extra, &cp, elem_len); + int32_t rule = idx >> 24; + idx &= 0xffffff; if (idx > 0) - for (i = 0; i < cset->nequiv_classes; ++i) - { - int32_t equiv_class_idx = cset->equiv_classes[i]; - size_t weight_len = weights[idx & 0xffffff]; - if (weight_len == weights[equiv_class_idx & 0xffffff] - && (idx >> 24) == (equiv_class_idx >> 24)) - { - Idx cnt = 0; - - idx &= 0xffffff; - equiv_class_idx &= 0xffffff; - - while (cnt <= weight_len - && (weights[equiv_class_idx + 1 + cnt] - == weights[idx + 1 + cnt])) - ++cnt; - if (cnt > weight_len) - { - match_len = elem_len; - goto check_node_accept_bytes_match; - } - } - } + { + size_t weight_len = weights[idx]; + for (i = 0; i < cset->nequiv_classes; ++i) + { + int32_t equiv_class_idx = cset->equiv_classes[i]; + int32_t equiv_class_rule = equiv_class_idx >> 24; + equiv_class_idx &= 0xffffff; + if (weights[equiv_class_idx] == weight_len + && equiv_class_rule == rule + && memcmp (weights + idx + 1, + weights + equiv_class_idx + 1, + weight_len) == 0) + { + match_len = elem_len; + goto check_node_accept_bytes_match; + } + } + } } } else |