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| author | Gustavo Niemeyer <gustavo@niemeyer.net> | 2002-11-07 03:28:56 (GMT) |
|---|---|---|
| committer | Gustavo Niemeyer <gustavo@niemeyer.net> | 2002-11-07 03:28:56 (GMT) |
| commit | c523b04b0f5cf76b503cfbed17fec95f61c1bd2e (patch) | |
| tree | 7017f4c0a06d96cce4af10ae4916fb9d032c2628 /Modules/_sre.c | |
| parent | 65fe8dda1588017bb5f15c8ab2fdbfb3b3c0bac7 (diff) | |
| download | cpython-c523b04b0f5cf76b503cfbed17fec95f61c1bd2e.zip cpython-c523b04b0f5cf76b503cfbed17fec95f61c1bd2e.tar.gz cpython-c523b04b0f5cf76b503cfbed17fec95f61c1bd2e.tar.bz2 | |
Fixed sre bug "[#581080] Provoking infinite scanner loops".
This bug happened because: 1) the scanner_search and scanner_match methods
were not checking the buffer limits before increasing the current pointer;
and 2) SRE_SEARCH was using "if (ptr == end)" as a loop break, instead of
"if (ptr >= end)".
* Modules/_sre.c
(SRE_SEARCH): Check for "ptr >= end" to break loops, so that we don't
hang forever if a pointer passing the buffer limit is used.
(scanner_search,scanner_match): Don't increment the current pointer
if we're going to pass the buffer limit.
* Misc/NEWS
Mention the fix.
Diffstat (limited to 'Modules/_sre.c')
| -rw-r--r-- | Modules/_sre.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/Modules/_sre.c b/Modules/_sre.c index 4440a6e..0357764 100644 --- a/Modules/_sre.c +++ b/Modules/_sre.c @@ -1237,7 +1237,7 @@ SRE_SEARCH(SRE_STATE* state, SRE_CODE* pattern) for (;;) { while (ptr < end && (SRE_CODE) ptr[0] != chr) ptr++; - if (ptr == end) + if (ptr >= end) return 0; TRACE(("|%p|%p|SEARCH LITERAL\n", pattern, ptr)); state->start = ptr; @@ -1254,7 +1254,7 @@ SRE_SEARCH(SRE_STATE* state, SRE_CODE* pattern) for (;;) { while (ptr < end && !SRE_CHARSET(charset, ptr[0])) ptr++; - if (ptr == end) + if (ptr >= end) return 0; TRACE(("|%p|%p|SEARCH CHARSET\n", pattern, ptr)); state->start = ptr; @@ -2896,7 +2896,8 @@ scanner_match(ScannerObject* self, PyObject* args) match = pattern_new_match((PatternObject*) self->pattern, state, status); - if (status == 0 || state->ptr == state->start) + if ((status == 0 || state->ptr == state->start) && + state->ptr < state->end) state->start = (void*) ((char*) state->ptr + state->charsize); else state->start = state->ptr; @@ -2927,7 +2928,8 @@ scanner_search(ScannerObject* self, PyObject* args) match = pattern_new_match((PatternObject*) self->pattern, state, status); - if (status == 0 || state->ptr == state->start) + if ((status == 0 || state->ptr == state->start) && + state->ptr < state->end) state->start = (void*) ((char*) state->ptr + state->charsize); else state->start = state->ptr; |