FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

gh-145376: Fix reference leaks in _collectionsmodule.c by eendebakpt · Pull Request #145421 · python/cpython · GitHub

  1. python
  2. cpython

Repository navigation

gh-145376: Fix reference leaks in _collectionsmodule.c #145421

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
vstinner merged 1 commit into from
Mar 4, 2026
+6 −3
Conversation 7 Commits 1 Checks 51 Files changed 1
Merged

gh-145376: Fix reference leaks in _collectionsmodule.c #145421

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

Filter by extension

Filter by extension .c  (1) All 1 file type selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
9 changes: 6 additions & 3 deletions Modules/_collectionsmodule.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -342,8 +342,10 @@ deque_append_lock_held(dequeobject *deque, PyObject *item, Py_ssize_t maxlen)
{
if (deque->rightindex == BLOCKLEN - 1) {
block *b = newblock(deque);
if (b == NULL)
if (b == NULL) {
Py_DECREF(item);
return -1;
}
b->leftlink = deque->rightblock;
CHECK_END(deque->rightblock->rightlink);
deque->rightblock->rightlink = b;
Expand Down Expand Up @@ -389,8 +391,10 @@ deque_appendleft_lock_held(dequeobject *deque, PyObject *item,
{
if (deque->leftindex == 0) {
block *b = newblock(deque);
if (b == NULL)
if (b == NULL) {
Py_DECREF(item);
return -1;
}
b->rightlink = deque->leftblock;
CHECK_END(deque->leftblock->leftlink);
deque->leftblock->leftlink = b;
Expand Down Expand Up @@ -564,7 +568,6 @@ deque_extendleft_impl(dequeobject *deque, PyObject *iterable)
iternext = *Py_TYPE(it)->tp_iternext;
while ((item = iternext(it)) != NULL) {
if (deque_appendleft_lock_held(deque, item, maxlen) == -1) {
Py_DECREF(item);

sergey-miryanov Mar 4, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

iternext returns a new reference. Should we leave this line unchanged?

encukou Mar 4, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

I agree, this is fishy. Does deque_append[left]_lock_held steal item, or not?

vstinner Mar 4, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

With this change, deque_appendleft_lock_held() always steal its item argument. So removing Py_DECREF(item) here is correct.

eendebakpt Mar 4, 2026

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

The deque_appendleft_lock_held indeed steals the second argument reference. I wrote this in the OP, but did not add a comment in the code.
If you agree, I will add a comment to the start of deque_append_lock_held/deque_appendleft_lock_held.

sergey-miryanov Mar 4, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

I see now, thanks!
Maybe it is worth to add a comment, that deque_appendleft_lock_held steals reference to the second argument?
Py_DECREF(it);
return NULL;
}
Expand Down
Loading
Back | FazBrowse Home | New Git URL