user/sven/linux.git/net/socket.c, branch v4.12.7

l2tp: device MTU setup, tunnel socket needs a lock

2017-04-17T17:01:48Z

The MTU overhead calculation in L2TP device set-up merged via commit b784e7ebfce8cfb16c6f95e14e8532d0768ab7ff needs to be adjusted to lock the tunnel socket while referencing the sub-data structures to derive the socket's IP overhead. Reported-by: Guillaume Nault Tested-by: Guillaume Nault Signed-off-by: R. Parameswaran Signed-off-by: David S. Miller

New kernel function to get IP overhead on a socket.

2017-04-06T20:43:31Z

A new function, kernel_sock_ip_overhead(), is provided to calculate the cumulative overhead imposed by the IP Header and IP options, if any, on a socket's payload. The new function returns an overhead of zero for sockets that do not belong to the IPv4 or IPv6 address families. This is used in the L2TP code path to compute the total outer IP overhead on the L2TP tunnel socket when calculating the default MTU for Ethernet pseudowires. Signed-off-by: R. Parameswaran Signed-off-by: David S. Miller

tcp: mark skbs with SCM_TIMESTAMPING_OPT_STATS

2017-03-22T01:44:17Z

SOF_TIMESTAMPING_OPT_STATS can be enabled and disabled while packets are collected on the error queue. So, checking SOF_TIMESTAMPING_OPT_STATS in sk->sk_tsflags is not enough to safely assume that the skb contains OPT_STATS data. Add a bit in sock_exterr_skb to indicate whether the skb contains opt_stats data. Fixes: 1c885808e456 ("tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING") Reported-by: JongHwan Kim Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Eric Dumazet Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

tcp: fix SCM_TIMESTAMPING_OPT_STATS for normal skbs

2017-03-22T01:44:17Z

__sock_recv_timestamp can be called for both normal skbs (for receive timestamps) and for skbs on the error queue (for transmit timestamps). Commit 1c885808e456 (tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING) assumes any skb passed to __sock_recv_timestamp are from the error queue, containing OPT_STATS in the content of the skb. This results in accessing invalid memory or generating junk data. To fix this, set skb->pkt_type to PACKET_OUTGOING for packets on the error queue. This is safe because on the receive path on local sockets skb->pkt_type is never set to PACKET_OUTGOING. With that, copy OPT_STATS from a packet, only if its pkt_type is PACKET_OUTGOING. Fixes: 1c885808e456 ("tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING") Reported-by: JongHwan Kim Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Eric Dumazet Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

net: Work around lockdep limitation in sockets that use sockets

2017-03-10T02:23:27Z

Lockdep issues a circular dependency warning when AFS issues an operation through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem. The theory lockdep comes up with is as follows: (1) If the pagefault handler decides it needs to read pages from AFS, it calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but creating a call requires the socket lock: mmap_sem must be taken before sk_lock-AF_RXRPC (2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind() binds the underlying UDP socket whilst holding its socket lock. inet_bind() takes its own socket lock: sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET (3) Reading from a TCP socket into a userspace buffer might cause a fault and thus cause the kernel to take the mmap_sem, but the TCP socket is locked whilst doing this: sk_lock-AF_INET must be taken before mmap_sem However, lockdep's theory is wrong in this instance because it deals only with lock classes and not individual locks. The AF_INET lock in (2) isn't really equivalent to the AF_INET lock in (3) as the former deals with a socket entirely internal to the kernel that never sees userspace. This is a limitation in the design of lockdep. Fix the general case by: (1) Double up all the locking keys used in sockets so that one set are used if the socket is created by userspace and the other set is used if the socket is created by the kernel. (2) Store the kern parameter passed to sk_alloc() in a variable in the sock struct (sk_kern_sock). This informs sock_lock_init(), sock_init_data() and sk_clone_lock() as to the lock keys to be used. Note that the child created by sk_clone_lock() inherits the parent's kern setting. (3) Add a 'kern' parameter to ->accept() that is analogous to the one passed in to ->create() that distinguishes whether kernel_accept() or sys_accept4() was the caller and can be passed to sk_alloc(). Note that a lot of accept functions merely dequeue an already allocated socket. I haven't touched these as the new socket already exists before we get the parameter. Note also that there are a couple of places where I've made the accepted socket unconditionally kernel-based: irda_accept() rds_rcp_accept_one() tcp_accept_from_sock() because they follow a sock_create_kern() and accept off of that. Whilst creating this, I noticed that lustre and ocfs don't create sockets through sock_create_kern() and thus they aren't marked as for-kernel, though they appear to be internal. I wonder if these should do that so that they use the new set of lock keys. Signed-off-by: David Howells Signed-off-by: David S. Miller

net: initialize msg.msg_flags in recvfrom

2017-03-10T01:21:21Z

KMSAN reports a use of uninitialized memory in put_cmsg() because msg.msg_flags in recvfrom haven't been initialized properly. The flag values don't affect the result on this path, but it's still a good idea to initialize them explicitly. Signed-off-by: Alexander Potapenko Signed-off-by: David S. Miller

net: socket: fix recvmmsg not returning error from sock_error

2017-02-21T18:35:25Z

Commit 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path"), changed the exit path of recvmmsg to always return the datagrams variable and modified the error paths to set the variable to the error code returned by recvmsg if necessary. However in the case sock_error returned an error, the error code was then ignored, and recvmmsg returned 0. Change the error path of recvmmsg to correctly return the error code of sock_error. The bug was triggered by using recvmmsg on a CAN interface which was not up. Linux 4.6 and later return 0 in this case while earlier releases returned -ENETDOWN. Fixes: 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path") Signed-off-by: Maxime Jayat Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-01-11T19:43:39Z

Two AF_* families adding entries to the lockdep tables at the same time. Signed-off-by: David S. Miller

net: socket: Make unnecessarily global sockfs_setattr() static

2017-01-10T16:29:50Z

Make sockfs_setattr() static as it is not used outside of net/socket.c This fixes the following GCC warning: net/socket.c:534:5: warning: no previous prototype for ‘sockfs_setattr’ [-Wmissing-prototypes] Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") Cc: Lorenzo Colitti Signed-off-by: Tobias Klauser Acked-by: Lorenzo Colitti Signed-off-by: David S. Miller

net: change init_inodecache() return void

2017-01-09T17:05:29Z

sock_init() call it but not check it's return value, so change it to void return and add an internal BUG_ON() check. Signed-off-by: yuan linyu Signed-off-by: David S. Miller