tee: Prevent size calculation wraparound on 32-bit kernels

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[ Upstream commit 39bb67edcc ]

The current code around TEE_IOCTL_PARAM_SIZE() is a bit wrong on
32-bit kernels: Multiplying a user-provided 32-bit value with the
size of a structure can wrap around on such platforms.

Fix it by using saturating arithmetic for the size calculation.

This has no security consequences because, in all users of
TEE_IOCTL_PARAM_SIZE(), the subsequent kcalloc() implicitly checks
for wrapping.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Tested-by: Rouven Czerwinski <rouven.czerwinski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

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Jann Horn 2025-04-28 15:06:43 +02:00 • committed by Greg Kroah-Hartman

parent a5cc6ccac4

commit dd89a7e18c

1 changed files with 6 additions and 5 deletions

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drivers/tee/tee_core.c

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