This reverts commits 6d04fe15f7 and
a31edb2059.
It turns out the idea to share a single pointer for both kernel and user
space address causes various kinds of problems. So use the slightly less
optimal version that uses an extra bit, but which is guaranteed to be safe
everywhere.
Fixes: 6d04fe15f7 ("net: optimize the sockptr_t for unified kernel/user address spaces")
Reported-by: Eric Dumazet <edumazet@google.com>
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sure not just the pointer itself but the whole range lies in
the user address space. For that pass the length and then use
the access_ok helper to do the check.
Fixes: 6d04fe15f7 ("net: optimize the sockptr_t for unified kernel/user address spaces")
Reported-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
sockptr_advance never properly worked. Replace it with _offset variants
of copy_from_sockptr and copy_to_sockptr.
Fixes: ba423fdaa5 ("net: add a new sockptr_t type")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While the kernel in general is not strict aliasing safe we can trivially
do that in sockptr_is_null without affecting code generation, so always
check the actually assigned union member.
Reported-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
For architectures like x86 and arm64 we don't need the separate bit to
indicate that a pointer is a kernel pointer as the address spaces are
unified. That way the sockptr_t can be reduced to a union of two
pointers, which leads to nicer calling conventions.
The only caveat is that we need to check that users don't pass in kernel
address and thus gain access to kernel memory. Thus the USER_SOCKPTR
helper is replaced with a init_user_sockptr function that does this check
and returns an error if it fails.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a uptr_t type that can hold a pointer to either a user or kernel
memory region, and simply helpers to copy to and from it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
