0001295: Apache crashes (SIGSEGV) when trying to establish connection when sockfd is large

ID	Project	Category	View Status	Date Submitted	Last Update
0001295	Xdebug	Uncategorized	public	2016-04-18 18:05	2016-11-12 16:53

Reporter	pkunyavskiy	Assigned To
Priority	normal	Severity	crash	Reproducibility	always
Status	closed	Resolution	fixed
Platform	Linux	OS	Debian	OS Version	7
Product Version	2.2.7
Fixed in Version	2.5.0RC1

Summary	0001295: Apache crashes (SIGSEGV) when trying to establish connection when sockfd is large
Description	In function xdebug_create_socket, you are using select function. If socket returns sockfd greater than or equals to 1024, select and other FD_ macroses will put garbage on system stack, which causes apache to SIGSEGV. Probably, it's actual to all versions later (current github version 2bfc4982b40622ea792da276f2d1c3bc8b6e8f98 has this bug).
Steps To Reproduce	Probably, have too many sites (with many ports to listen) on single apache.
Additional Information	Solution is simple: replace select with poll or epoll.
Tags	No tags attached.

Operating System
PHP Version	5.3.7

derick 2016-05-10 19:44 administrator ~0003589	Fixed in master on GitHub, as the code now uses poll() instead of select, which doesn't have this FD limit. As that PR also introduces a new feature, this won't be part of the 2.4.x series.