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| author | John MacFarlane <jgm@berkeley.edu> | 2017-06-29 10:01:34 +0200 |
|---|---|---|
| committer | John MacFarlane <jgm@berkeley.edu> | 2017-06-29 10:03:55 +0200 |
| commit | f8737b1c82981624b3263224dbf92fa6627f7205 (patch) | |
| tree | 56cbf6eb574aaf2230e560c950a13a8339bc9f27 | |
| parent | 09d96cd0b6f352227f741c4fc9b0d82cbefcc012 (diff) | |
latex writer: fix memory overflow.
We got an array overflow in enumerated lists nested more than
10 deep with start number =/= 1.
Found by google/oss-fuzz.
https://oss-fuzz.com/v2/testcase-detail/5546760854306816
This commit also ensures that we don't try to set `enum_` counters
that aren't defined by LaTeX (generally up to enumv).
Closes #210.
| -rw-r--r-- | src/latex.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/src/latex.c b/src/latex.c index 22052d7..f372a13 100644 --- a/src/latex.c +++ b/src/latex.c @@ -220,11 +220,10 @@ static int S_get_enumlevel(cmark_node *node) { static int S_render_node(cmark_renderer *renderer, cmark_node *node, cmark_event_type ev_type, int options) { int list_number; + int enumlevel; char list_number_string[LIST_NUMBER_STRING_SIZE]; bool entering = (ev_type == CMARK_EVENT_ENTER); cmark_list_type list_type; - const char *roman_numerals[] = {"", "i", "ii", "iii", "iv", "v", - "vi", "vii", "viii", "ix", "x"}; bool allow_wrap = renderer->width > 0 && !(CMARK_OPT_NOBREAKS & options); // avoid warning about unused parameter: @@ -253,13 +252,24 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node, CR(); list_number = cmark_node_get_list_start(node); if (list_number > 1) { - snprintf(list_number_string, LIST_NUMBER_STRING_SIZE, "%d", - list_number); - LIT("\\setcounter{enum"); - LIT((char *)roman_numerals[S_get_enumlevel(node)]); - LIT("}{"); - OUT(list_number_string, false, NORMAL); - LIT("}"); + enumlevel = S_get_enumlevel(node); + // latex normally supports only five levels + if (enumlevel >= 1 && enumlevel <= 5) { + snprintf(list_number_string, LIST_NUMBER_STRING_SIZE, "%d", + list_number); + LIT("\\setcounter{enum"); + switch(enumlevel) { + case 1: LIT("i"); break; + case 2: LIT("ii"); break; + case 3: LIT("iii"); break; + case 4: LIT("iv"); break; + case 5: LIT("v"); break; + default: LIT("i"); break; + } + LIT("}{"); + OUT(list_number_string, false, NORMAL); + LIT("}"); + } CR(); } } else { |