Описание
In the Linux kernel, the following vulnerability has been resolved:
jbd2: bound shrinker scans by examined checkpoint buffers
The jbd2 shrinker currently accounts only checkpoint buffers that it
successfully releases against nr_to_scan. Busy buffers therefore do not
consume the scan budget.
If a checkpoint transaction contains mostly busy buffers, the shrinker
can scan its entire checkpoint list while holding journal->j_list_lock.
Large checkpoint lists can result in excessive lock hold times and leave
other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls.
Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for
every buffer examined, including busy buffers. Pass NULL from checkpoint
cleanup paths so their existing full-list behavior is preserved.
This restores the scan-budget semantics that existed before
journal_shrink_one_cp_list() was changed to always scan a complete
checkpoint list.
A flaw was found in the Linux kernel's jbd2 shrinker. This component, which manages journal buffers, does not correctly account for busy checkpoint buffers. This oversight can cause the shrinker to hold a critical system lock for an extended period when processing many busy buffers. The prolonged lock contention can lead to system unresponsiveness, such as soft lockups or RCU stalls, ultimately resulting in a Denial of Service (DoS).
Ссылки на источники
Дополнительная информация
Статус:
EPSS
4.7 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: jbd2: bound shrinker scans by examined checkpoint buffers The jbd2 shrinker currently accounts only checkpoint buffers that it successfully releases against nr_to_scan. Busy buffers therefore do not consume the scan budget. If a checkpoint transaction contains mostly busy buffers, the shrinker can scan its entire checkpoint list while holding journal->j_list_lock. Large checkpoint lists can result in excessive lock hold times and leave other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls. Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for every buffer examined, including busy buffers. Pass NULL from checkpoint cleanup paths so their existing full-list behavior is preserved. This restores the scan-budget semantics that existed before journal_shrink_one_cp_list() was changed to always scan a complete checkpoint list.
In the Linux kernel, the following vulnerability has been resolved: jbd2: bound shrinker scans by examined checkpoint buffers The jbd2 shrinker currently accounts only checkpoint buffers that it successfully releases against nr_to_scan. Busy buffers therefore do not consume the scan budget. If a checkpoint transaction contains mostly busy buffers, the shrinker can scan its entire checkpoint list while holding journal->j_list_lock. Large checkpoint lists can result in excessive lock hold times and leave other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls. Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for every buffer examined, including busy buffers. Pass NULL from checkpoint cleanup paths so their existing full-list behavior is preserved. This restores the scan-budget semantics that existed before journal_shrink_one_cp_list() was changed to always scan a complete checkpoint list.
In the Linux kernel, the following vulnerability has been resolved: j ...
In the Linux kernel, the following vulnerability has been resolved: jbd2: bound shrinker scans by examined checkpoint buffers The jbd2 shrinker currently accounts only checkpoint buffers that it successfully releases against nr_to_scan. Busy buffers therefore do not consume the scan budget. If a checkpoint transaction contains mostly busy buffers, the shrinker can scan its entire checkpoint list while holding journal->j_list_lock. Large checkpoint lists can result in excessive lock hold times and leave other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls. Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for every buffer examined, including busy buffers. Pass NULL from checkpoint cleanup paths so their existing full-list behavior is preserved. This restores the scan-budget semantics that existed before journal_shrink_one_cp_list() was changed to always scan a complete checkpoint list.
EPSS
4.7 Medium
CVSS3