s390/zcrypt: Validate length in reply before using it

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The length information in the reply is used to copy the key token to
the target buffer. An invalid information in t->len of the reply may
cause an over-read of the target buffer and also a over-write of the
target buffer. To prevent that, check t->len before using it.

As the available space in destination and source buffer is always
larger than the valid length value in the parameter block in the
reply, compare t->len with this (already validated) length
information. As a side effect, this check also prevents buffer
over-read and over-write.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

...

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Holger Dengler 2026-08-20 17:50:03 +02:00 • committed by Heiko Carstens

parent 8ac60ae2a3

commit a91a5c25a2

1 changed files with 14 additions and 1 deletions

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drivers/s390/crypto/zcrypt_ccamisc.c

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