Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Stop remote reader update when page swap fails
The remote swap_reader_page callback can return -EBUSY when the writer moves the head before the remote catches it, particularly during an event storm on a small buffer. __rb_get_reader_page_from_remote() currently warns about that failure but continues with the unchanged reader ID and rearranges the local page list as though the swap succeeded.
Handle the callback failure as a recoverable error. Report it with pr_warn_ratelimited() and return NULL. Callers already handle a NULL reader page as a failed attempt. This avoids splicing the same page as both the previous and new reader without flooding the log under contention.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS
- Affected packages:
- linux @ 5.10.259 (+1 more)