android_kernel_google_msm/include
Lorenzo Colitti d3cd043531 net: core: Add a UID field to struct sock.
Protocol sockets (struct sock) don't have UIDs, but most of the
time, they map 1:1 to userspace sockets (struct socket) which do.

Various operations such as the iptables xt_owner match need
access to the "UID of a socket", and do so by following the
backpointer to the struct socket. This involves taking
sk_callback_lock and doesn't work when there is no socket
because userspace has already called close().

Simplify this by adding a sk_uid field to struct sock whose value
matches the UID of the corresponding struct socket. The semantics
are as follows:

1. Whenever sk_socket is non-null: sk_uid is the same as the UID
   in sk_socket, i.e., matches the return value of sock_i_uid.
   Specifically, the UID is set when userspace calls socket(),
   fchown(), or accept().
2. When sk_socket is NULL, sk_uid is defined as follows:
   - For a socket that no longer has a sk_socket because
     userspace has called close(): the previous UID.
   - For a cloned socket (e.g., an incoming connection that is
     established but on which userspace has not yet called
     accept): the UID of the socket it was cloned from.
   - For a socket that has never had an sk_socket: UID 0 inside
     the user namespace corresponding to the network namespace
     the socket belongs to.

Kernel sockets created by sock_create_kern are a special case
of #1 and sk_uid is the user that created them. For kernel
sockets created at network namespace creation time, such as the
per-processor ICMP and TCP sockets, this is the user that created
the network namespace.

[Backport of net-next 86741ec25462e4c8cdce6df2f41ead05568c7d5e]

Bug: 16355602
Change-Id: I73e1a57dfeedf672f4c2dfc9ce6867838b55974b
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>
2023-02-18 18:37:04 +01:00
..
acpi
asm-generic locks: rename file-private locks to "open file description locks" 2021-01-24 09:56:22 +00:00
crypto
drm
keys
linux BACKPORT: ipc: add COMPAT_SHMLBA support 2023-02-18 18:32:08 +01:00
math-emu
media
misc
mtd
net net: core: Add a UID field to struct sock. 2023-02-18 18:37:04 +01:00
pcmcia
rdma
rxrpc
scsi
sound
target
trace
uapi/linux shm: add memfd_create() syscall 2020-10-25 02:37:54 -04:00
video
xen
Kbuild Revert "shm: add memfd.h to export list" 2020-12-12 13:05:55 +03:00