Skip to content

[3.15] gh-156939: Fix xmlcharrefreplace() buffer overflow (GH-157109) #157232

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
miss-islington wants to merge 1 commit into
base: 3.15
Choose a base branch
from
+10 −4
Open

[3.15] gh-156939: Fix xmlcharrefreplace() buffer overflow (GH-157109) #157232

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 10 additions & 4 deletions Objects/unicodeobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -875,10 +875,16 @@ xmlcharrefreplace(PyBytesWriter *writer, char *str,

/* generate replacement */
for (i = collstart; i < collend; ++i) {
size = sprintf(str, "&#%d;", PyUnicode_READ(kind, data, i));
if (size < 0) {
return NULL;
}
// Use snprintf() with a temporary buffer to not write the trailing
// NUL byte in the writer buffer.
Py_BUILD_ASSERT(_Py_MAX_UNICODE <= 0x10ffff);
// len('&#1114111;\0') is 11 bytes.
char buffer[11];
Py_UCS4 ch = PyUnicode_READ(kind, data, i);
size = snprintf(buffer, sizeof(buffer), "&#%d;", ch);
assert(4 <= size && (size_t)size <= (sizeof(buffer) - 1));

memcpy(str, buffer, size);
str += size;
}
return str;
Expand Down
Loading