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[2.7] bpo-34395: Fix memory leaks caused by incautious usage of PyMem_Resize(). (GH-8756) #8785

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Merged
merged 5 commits into from
Aug 17, 2018
Merged

[2.7] bpo-34395: Fix memory leaks caused by incautious usage of PyMem_Resize(). (GH-8756) #8785

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b1dc0a4
bpo-34395: Fix memory leaks in csv module.
sir-sigurd Aug 16, 2018
5315d2f
Fix var name.
sir-sigurd Aug 16, 2018
458c8b3
Move variable declarations for C89 compliance.
sir-sigurd Aug 16, 2018
d83927a
Add forgotten semicolon.
sir-sigurd Aug 16, 2018
9ebc70b
Use PyMem_Realloc().
serhiy-storchaka Aug 16, 2018
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56 changes: 24 additions & 32 deletions Modules/_csv.c
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Original file line number Diff line number Diff line change
Expand Up @@ -565,24 +565,23 @@ parse_save_field(ReaderObj *self)
static int
parse_grow_buff(ReaderObj *self)
{
if (self->field_size == 0) {
self->field_size = 4096;
if (self->field != NULL)
PyMem_Free(self->field);
self->field = PyMem_Malloc(self->field_size);
}
else {
if (self->field_size > INT_MAX / 2) {
PyErr_NoMemory();
return 0;
}
self->field_size *= 2;
self->field = PyMem_Realloc(self->field, self->field_size);
unsigned field_size_new;
char *field_new;

assert((unsigned)self->field_size <= INT_MAX);

field_size_new = self->field_size ? 2 * (unsigned)self->field_size : 4096;
if (field_size_new > INT_MAX) {
PyErr_NoMemory();
return 0;
}
if (self->field == NULL) {
field_new = (char *)PyMem_Realloc(self->field, field_size_new);
if (field_new == NULL) {
PyErr_NoMemory();
return 0;
}
self->field = field_new;
self->field_size = (int)field_size_new;
return 1;
}

Expand Down Expand Up @@ -1088,31 +1087,24 @@ join_append_data(WriterObj *self, char *field, int quote_empty,
static int
join_check_rec_size(WriterObj *self, int rec_len)
{
unsigned rec_size_new;
char *rec_new;

if (rec_len < 0 || rec_len > INT_MAX - MEM_INCR) {
PyErr_NoMemory();
return 0;
}
assert(rec_len >= 0);

if (rec_len > self->rec_size) {
if (self->rec_size == 0) {
self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;
if (self->rec != NULL)
PyMem_Free(self->rec);
self->rec = PyMem_Malloc(self->rec_size);
}
else {
char *old_rec = self->rec;

self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;
self->rec = PyMem_Realloc(self->rec, self->rec_size);
if (self->rec == NULL)
PyMem_Free(old_rec);
rec_size_new = (unsigned)(rec_len / MEM_INCR + 1) * MEM_INCR;
if (rec_size_new > INT_MAX) {
PyErr_NoMemory();
return 0;
}
if (self->rec == NULL) {
rec_new = (char *)PyMem_Realloc(self->rec, rec_size_new);
if (rec_new == NULL) {
PyErr_NoMemory();
return 0;
}
self->rec = rec_new;
self->rec_size = (int)rec_size_new;
}
return 1;
}
Expand Down