> On Oct 26, 2022, at 19:32, Kees Cook <[email protected]> wrote:
>
> On Sun, Oct 16, 2022 at 09:36:50PM -0700, Kees Cook wrote:
>> The 'nfs_server' and 'mount_server' structures include a union of
>> 'struct sockaddr' (with the older 16 bytes max address size) and
>> 'struct sockaddr_storage' which is large enough to hold all the
>> supported sa_family types (128 bytes max size). The runtime memcpy()
>> buffer overflow checker is seeing attempts to write beyond the 16
>> bytes as an overflow, but the actual expected size is that of 'struct
>> sockaddr_storage'. Plumb the use of 'struct sockaddr_storage' more
>> completely through-out NFS, which results in adjusting the memcpy()
>> buffers to the correct union members. Avoids this false positive run-time
>> warning under CONFIG_FORTIFY_SOURCE:
>>
>> memcpy: detected field-spanning write (size 28) of single field "&ctx->nfs_server.address" at fs/nfs/namespace.c:178 (size 16)
>>
>> Reported-by: kernel test robot <[email protected]>
>> Link: https://lore.kernel.org/all/[email protected]
>> Cc: Trond Myklebust <[email protected]>
>> Cc: Anna Schumaker <[email protected]>
>
> Friendly ping -- this needs to land in v6.1 to avoid these warnings.
> Should I carry this in the hardening tree instead?
>
> Thanks!
Anna, this is your call since you’re the ‘6.1 nfs client maintainer’...
_________________________________
Trond Myklebust
Linux NFS client maintainer, Hammerspace
[email protected]