Closed shinmao closed 8 months ago
Hi, we found that the function from_bytes might cover unsound transmute: https://github.com/rust-util-collections/vsdb/blob/50a45dc4d4b2f563153a514327ec1009957daa13/wrappers/src/common/ende.rs#L405-L417 From my understanding, the deallocator should keep the same layout as it was allocated with; otherwise it could lead to UB. In from_bytes, Vec<u8> is allowed to transmute to Vec<u16>, Vec<u32> Vec<usize>, Vec<u128> and so on. However, we can see that the clippy lint of transmute was suppressed, https://github.com/rust-util-collections/vsdb/blob/50a45dc4d4b2f563153a514327ec1009957daa13/wrappers/src/common/ende.rs#L372 Could you explain more about how you guarantee the transmute between different layout of allocator and deallocator? Thanks!
from_bytes
Vec<u8>
Vec<u16>
Vec<u32>
Vec<usize>
Vec<u128>
they are well aligned types
haxjump
commented
1 year ago haxjump
commented
1 year ago
Hi, we found that the function
from_bytesmight cover unsound transmute: https://github.com/rust-util-collections/vsdb/blob/50a45dc4d4b2f563153a514327ec1009957daa13/wrappers/src/common/ende.rs#L405-L417 From my understanding, the deallocator should keep the same layout as it was allocated with; otherwise it could lead to UB. Infrom_bytes,Vec<u8>is allowed to transmute toVec<u16>,Vec<u32>Vec<usize>,Vec<u128>and so on. However, we can see that the clippy lint of transmute was suppressed, https://github.com/rust-util-collections/vsdb/blob/50a45dc4d4b2f563153a514327ec1009957daa13/wrappers/src/common/ende.rs#L372 Could you explain more about how you guarantee the transmute between different layout of allocator and deallocator? Thanks!