nginx/nginx

Potential null dereference in ngx_time.c

Closed

#169 opened on Sep 12, 2024

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 (3 comments) (0 reactions) (1 assignee)C (7,903 forks)batch import
Complexity - hardbuggood first issue

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Description

In results of static analyze of nginx sources I founded potential null dereference

https://github.com/nginx/nginx/blob/00637cce366f17b78fe1ed5c1ef0e534143045f6/src/os/unix/ngx_time.c#L48-L50

localtime() function potentially can return NULL value, which will dereference in strftime(). How about to add check for this case?

Contributor guide

Research direction
Review the code at the provided link (ngx time.c lines 48-50). Implement a null check for the return value of localtime() before passing to strftime(). Consider using localtime r() if thread safety is a concern. Ensure the fix does not introduce any regression.
Tech stack
c
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C programmingunderstanding of localtime()
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70