[ Upstream commit e5c5f3596de224422561d48eba6ece5210d967b3 ]
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].
As the "ids" variable is a pointer to "struct sctp_assoc_ids" and this
structure ends in a flexible array:
struct sctp_assoc_ids {
[...]
sctp_assoc_t gaids_assoc_id[];
};
the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the calculation "size + size * count" in
the kmalloc() function.
Also, refactor the code adding the "ids_size" variable to avoid sizing
twice.
This way, the code is more readable and safer.
This code was detected with the help of Coccinelle, and audited and
modified manually.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/160 [2]
Signed-off-by: Erick Archer <erick.archer@outlook.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/PAXPR02MB724871DB78375AB06B5171C88B152@PAXPR02MB7248.eurprd02.prod.outlook.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
