cbcvebase.
CVE-2021-47365
published 2024-05-21

CVE-2021-47365: In the Linux kernel, the following vulnerability has been resolved: afs: Fix page leak There's a loop in afs_extend_writeback() that adds extra pages to a…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.21%
11.0th percentile
In the Linux kernel, the following vulnerability has been resolved: afs: Fix page leak There's a loop in afs_extend_writeback() that adds extra pages to a write we want to make to improve the efficiency of the writeback by making it larger. This loop stops, however, if we hit a page we can't write back from immediately, but it doesn't get rid of the page ref we speculatively acquired. This was caused by the removal of the cleanup loop when the code switched from using find_get_pages_contig() to xarray scanning as the latter only gets a single page at a time, not a batch. Fix this by putting the page on a ref on an early break from the loop. Unfortunately, we can't just add that page to the pagevec we're employing as we'll go through that and add those pages to the RPC call. This was found by the generic/074 test. It leaks ~4GiB of RAM each time it is run - which can be observed with "top".

Affected

10 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.14.9-1 (bookworm)linux 5.14.9-1 (bookworm)
linuxlinux
linuxlinux>= e87b03f5830ecd8ca21836d3ee48c74f8d58fa31 < d130b5fdd42254d92948d06347940276140c927ed130b5fdd42254d92948d06347940276140c927e
linuxlinux>= e87b03f5830ecd8ca21836d3ee48c74f8d58fa31 < 581b2027af0018944ba301d68e7af45c6d1128b5581b2027af0018944ba301d68e7af45c6d1128b5
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.14.9-15.14.9-1
linuxlinux_kernel>= 0 < 5.14.9-15.14.9-1
linuxlinux_kernel>= 0 < 5.14.9-15.14.9-1
linuxlinux_kernel>= 5.13 < 5.14.95.14.9

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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