ilusha/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython synced 2026-09-29 12:10:30 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

Close #16742: Fix misuse of memory allocations in PyOS_Readline()

Browse source 
The GIL must be held to call PyMem_Malloc(), whereas PyOS_Readline() releases
the GIL to read input.

The result of the C callback PyOS_ReadlineFunctionPointer must now be a string
allocated by PyMem_RawMalloc() or PyMem_RawRealloc() (or NULL if an error
occurred), instead of a string allocated by PyMem_Malloc() or PyMem_Realloc().

Fixing this issue was required to setup a hook on PyMem_Malloc(), for example
using the tracemalloc module.

PyOS_Readline() copies the result of PyOS_ReadlineFunctionPointer() into a new
buffer allocated by PyMem_Malloc(). So the public API of PyOS_Readline() does
not change.
This commit is contained in:
Victor Stinner 2013-10-10 16:18:20 +02:00
parent 6cf185dc06
commit 2fe9bac4dc
5 changed files with 41 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

26
Parser/myreadline.c
View file

@ -113,18 +113,22 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
{
size_t n;
char *p, *pr;
n = 100;
if ((p = (char *)PyMem_MALLOC(n)) == NULL)
p = (char *)PyMem_RawMalloc(n);
if (p == NULL)
return NULL;
fflush(sys_stdout);
if (prompt)
fprintf(stderr, "%s", prompt);
fflush(stderr);
switch (my_fgets(p, (int)n, sys_stdin)) {
case 0: /* Normal case */
break;
case 1: /* Interrupt */
PyMem_FREE(p);
PyMem_RawFree(p);
return NULL;
case -1: /* EOF */
case -2: /* Error */
@ -140,7 +144,7 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
PyErr_SetString(PyExc_OverflowError, "input line too long");
return NULL;
}
pr = (char *)PyMem_REALLOC(p, n + incr);
pr = (char *)PyMem_RawRealloc(p, n + incr);
if (pr == NULL) {
PyMem_FREE(p);
PyErr_NoMemory();
@ -151,7 +155,7 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
break;
n += strlen(p+n);
}
pr = (char *)PyMem_REALLOC(p, n+1);
pr = (char *)PyMem_RawRealloc(p, n+1);
if (pr == NULL) {
PyMem_FREE(p);
PyErr_NoMemory();
@ -174,7 +178,8 @@ char *(*PyOS_ReadlineFunctionPointer)(FILE *, FILE *, char *);
char *
PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
{
char *rv;
char *rv, *res;
size_t len;
if (_PyOS_ReadlineTState == PyThreadState_GET()) {
PyErr_SetString(PyExc_RuntimeError,
@ -221,5 +226,14 @@ PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
_PyOS_ReadlineTState = NULL;
return rv;
if (rv == NULL)
return NULL;
len = strlen(rv) + 1;
res = PyMem_Malloc(len);
if (res != NULL)
memcpy(res, rv, len);
PyMem_RawFree(rv);
return res;
}