lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 26 Oct 2022 16:32:40 -0700
From:   Kees Cook <>
To:     Trond Myklebust <>
Cc:     kernel test robot <>,
        Anna Schumaker <>,,
        Dave Jones <>,
        Bagas Sanjaya <>,,
Subject: Re: [PATCH v2] NFS: Avoid memcpy() run-time warning for struct
 sockaddr overflows

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 <>
> Link:
> Cc: Trond Myklebust <>
> Cc: Anna Schumaker <>

Friendly ping -- this needs to land in v6.1 to avoid these warnings.
Should I carry this in the hardening tree instead?



Kees Cook

Powered by blists - more mailing lists