The __is_valid_access() test for cb[] from
62c7989b24db ("bpf: allow
b/h/w/dw access for bpf's cb in ctx") was done unnecessarily complex,
we can just simplify it the same way as recent fix from
2d071c643f1c
("bpf, trace: make ctx access checks more robust") did. Overflow can
never happen as size is 1/2/4/8 depending on access.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
switch (off) {
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
switch (off) {
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
- if (size == sizeof(__u16) &&
- off > offsetof(struct __sk_buff, cb[4]) + sizeof(__u16))
- return false;
- if (size == sizeof(__u32) &&
- off > offsetof(struct __sk_buff, cb[4]))
- return false;
- if (size == sizeof(__u64) &&
- off > offsetof(struct __sk_buff, cb[2]))
- return false;
- if (size != sizeof(__u8) &&
- size != sizeof(__u16) &&
- size != sizeof(__u32) &&
- size != sizeof(__u64))
+ if (off + size >
+ offsetof(struct __sk_buff, cb[4]) + sizeof(__u32))
return false;
break;
default:
return false;
break;
default: