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CVE-2021-47365

Опубликовано: 21 мая 2024
Источник: nvd
CVSS3: 5.5
EPSS Низкий

Описание

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".

Уязвимые конфигурации

Конфигурация 1

Одно из

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 5.13 (включая) до 5.14.9 (исключая)
cpe:2.3:o:linux:linux_kernel:5.14.9:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*

EPSS

Процентиль: 1%
0.00008
Низкий

5.5 Medium

CVSS3

Дефекты

CWE-459

Связанные уязвимости

CVSS3: 5.5
ubuntu
больше 1 года назад

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".

CVSS3: 5.5
redhat
больше 1 года назад

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".

CVSS3: 5.5
debian
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: a ...

CVSS3: 5.5
github
больше 1 года назад

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".

CVSS3: 5.5
fstec
больше 4 лет назад

Уязвимость функции afs_extend_writeback() модуля fs/afs/write.c поддержки файловой системы ядра операционной системы Linux, позволяющая нарушителю получить доступ к защищаемой информации

EPSS

Процентиль: 1%
0.00008
Низкий

5.5 Medium

CVSS3

Дефекты

CWE-459