Skip to content

gh-101178: Fix UB in binascii.b2a_ascii85#148166

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

Merged
StanFromIreland merged 1 commit into from
Apr 7, 2026
Merged

gh-101178: Fix UB in binascii.b2a_ascii85#148166

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
4 changes: 2 additions & 2 deletions Modules/binascii.c
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1240,7 +1240,7 @@ binascii_b2a_ascii85_impl(PyObject *module, Py_buffer *data, int foldspaces,

/* Encode all full-length chunks. */
for (; bin_len >= 4; bin_len -= 4, bin_data += 4) {
uint32_t leftchar = (bin_data[0] << 24) | (bin_data[1] << 16) |
uint32_t leftchar = ((uint32_t)bin_data[0] << 24) | (bin_data[1] << 16) |
(bin_data[2] << 8) | bin_data[3];
if (leftchar == BASE85_A85_Z) {
*ascii_data++ = 'z';
Expand DownExpand Up@@ -1481,7 +1481,7 @@ binascii_b2a_base85_impl(PyObject *module, Py_buffer *data, int pad,

/* Encode all full-length chunks. */
for (; bin_len >= 4; bin_len -= 4, bin_data += 4) {
uint32_t leftchar = (bin_data[0] << 24) | (bin_data[1] << 16) |
uint32_t leftchar = ((uint32_t)bin_data[0] << 24) | (bin_data[1] << 16) |
(bin_data[2] << 8) | bin_data[3];

ascii_data[4] = table_b2a[leftchar % 85];
Expand Down
Loading