Skip to content

Fix apply na overflow #56000

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
merged 4 commits into from
Nov 17, 2023
Merged

Fix apply na overflow #56000

Changes from 3 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
9e3d15f
fix groupby and apply UB
WillAyd Nov 16, 2023
01b2752
fix/skip parser overflow
WillAyd Nov 16, 2023
bc474ba
revert unneeded
WillAyd Nov 16, 2023
7152098
feedback
WillAyd Nov 17, 2023
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
5 changes: 4 additions & 1 deletion pandas/core/methods/selectn.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -139,7 +139,10 @@ def compute(self, method: str) -> Series:

# arr passed into kth_smallest must be contiguous. We copy
# here because kth_smallest will modify its input
kth_val = libalgos.kth_smallest(arr.copy(order="C"), n - 1)
if n == 0: # avoid OOB access with kth_smallest_c
kth_val = 0
else:
kth_val = libalgos.kth_smallest(arr.copy(order="C"), n - 1)
Copy link
Member

Choose a reason for hiding this comment

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

Suggested change
if n == 0: # avoid OOB access with kth_smallest_c
kth_val = 0
else:
kth_val = libalgos.kth_smallest(arr.copy(order="C"), n - 1)
# avoid OOB access with kth_smallest_c
kth_val = libalgos.kth_smallest(arr.copy(order="C"), max(n - 1, 0))

I would be more comfortable with this change. Since kth_val is a value in the array and comparisons are made with this value, this may be incorrect if values in arr were all negative for example

Copy link
Member Author

Choose a reason for hiding this comment

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

Nice idea

(ns,) = np.nonzero(arr <= kth_val)
inds = ns[arr[ns].argsort(kind="mergesort")]

Expand Down