IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
Now kfunc call uses s32 to represent the offset between the address of
kfunc and __bpf_call_base, but it doesn't check whether or not s32 will
be overflowed. The overflow is possible when kfunc is in module and the
offset between module and kernel is greater than 2GB. Take arm64 as an
example, before commit b2eed9b588 ("arm64/kernel: kaslr: reduce module
randomization range to 2 GB"), the offset between module symbol and
__bpf_call_base will in 4GB range due to KASLR and may overflow s32.
So add an extra checking to reject these invalid kfunc calls.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220215065732.3179408-1-houtao1@huawei.com