Fix null dereference and iface overrun in getifaddrs path#158
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andy5995 wants to merge 1 commit intolibsdl-org:mainfrom
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Fix null dereference and iface overrun in getifaddrs path#158andy5995 wants to merge 1 commit intolibsdl-org:mainfrom
andy5995 wants to merge 1 commit intolibsdl-org:mainfrom
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POSIX allows ifa_addr to be NULL (e.g. interfaces with no assigned address). Add an explicit NULL check and skip such entries, adjusting new_num_interfaces since they were counted in the first pass. The loop also had iface++ in the for-header, so any continue — including the ifa_name == NULL early-out — would still advance the pointer past an unfilled slot. Since NULL-named entries were not counted in the sizing pass, this caused subsequent slot writes to go out of bounds. Fix by moving iface++ to the bottom of the loop body so it only fires when a slot is actually filled, and remove the now-unnecessary iface-- that was compensating for the old premature increment. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Here's what @claude found. Looks ok to me...
POSIX allows ifa_addr to be NULL (e.g. interfaces with no assigned address). Add an explicit NULL check and skip such entries, adjusting new_num_interfaces since they were counted in the first pass.
The loop also had iface++ in the for-header, so any continue — including the ifa_name == NULL early-out — would still advance the pointer past an unfilled slot. Since NULL-named entries were not counted in the sizing pass, this caused subsequent slot writes to go out of bounds. Fix by moving iface++ to the bottom of the loop body so it only fires when a slot is actually filled, and remove the now-unnecessary iface-- that was compensating for the old premature increment.