CVE-2026-68147
Gravedad CVSS v3.1:
ALTA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
10/08/2026
Última modificación:
19/08/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
fscrypt: Avoid dynamic allocation in fscrypt_get_devices()<br />
<br />
When a blk_crypto_key starts being used or is evicted, fs/crypto/ calls<br />
fscrypt_get_devices() to get the filesystem&#39;s list of block devices,<br />
then iterates over them and calls blk_crypto_config_supported(),<br />
blk_crypto_start_using_key(), or blk_crypto_evict_key() on each one.<br />
<br />
Currently, the block device pointers are placed in a dynamically<br />
allocated array. This dynamic allocation is problematic because:<br />
<br />
- It can fail, especially at the fscrypt_destroy_inline_crypt_key() call<br />
site when it&#39;s invoked for inode eviction under direct reclaim.<br />
<br />
- fscrypt_destroy_inline_crypt_key() doesn&#39;t handle the failure. It<br />
just zeroizes and frees the blk_crypto_key without calling<br />
blk_crypto_evict_key(). That causes a use-after-free.<br />
<br />
For now, let&#39;s fix this in the straightforward and easily-backportable<br />
way by switching to an on-stack array. Currently the fscrypt<br />
multi-device functionality is used only by f2fs, which has a hardcoded<br />
limit of 8 block devices. An on-stack array works fine for that.<br />
<br />
(Of course, this solution won&#39;t scale up to large number of block<br />
devices. For that we&#39;d need a different solution, like moving the block<br />
device iteration into the filesystem. Or in the case of btrfs, which<br />
will only support blk-crypto-fallback, we should make it just call<br />
blk-crypto-fallback directly, so the block devices won&#39;t be needed.)
Impacto
Puntuación base 3.x
7.80
Gravedad 3.x
ALTA
Referencias a soluciones, herramientas e información
- https://git.kernel.org/stable/c/4462ac3d90e897dda52ce4b6af2d526ddae835a8
- https://git.kernel.org/stable/c/6fe4e4b8259e1330945b5f3c9476e08473b8e0e8
- https://git.kernel.org/stable/c/81ea8e8221853950c47dac7164f27c63a96f8f86
- https://git.kernel.org/stable/c/97a688563be71ec6fefc071aff69a66c69dbe244
- https://git.kernel.org/stable/c/bab016bb80d74a9d1f7d4121a7fc1cb529b470e0
- https://git.kernel.org/stable/c/bc2d630296e0e049210ec05ff08459a6893ae749


