talos-obmc-linux/net/socket.c, branch v4.4.16

net: Fix use after free in the recvmmsg exit path

2016-04-20T06:42:03+00:00

[ Upstream commit 34b88a68f26a75e4fded796f1a49c40f82234b7d ] The syzkaller fuzzer hit the following use-after-free: Call Trace: [] __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:295 [] __sys_recvmmsg+0x6fa/0x7f0 net/socket.c:2261 [< inline >] SYSC_recvmmsg net/socket.c:2281 [] SyS_recvmmsg+0x16f/0x180 net/socket.c:2270 [] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 And, as Dmitry rightly assessed, that is because we can drop the reference and then touch it when the underlying recvmsg calls return some packets and then hit an error, which will make recvmmsg to set sock->sk->sk_err, oops, fix it. Reported-and-Tested-by: Dmitry Vyukov Cc: Alexander Potapenko Cc: Eric Dumazet Cc: Kostya Serebryany Cc: Sasha Levin Fixes: a2e2725541fa ("net: Introduce recvmmsg socket syscall") http://lkml.kernel.org/r/20160122211644.GC2470@redhat.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net, socket, socket_wq: fix missing initialization of flags

2015-12-30T21:38:01+00:00

Commit ceb5d58b2170 ("net: fix sock_wake_async() rcu protection") from the current 4.4 release cycle introduced a new flags member in struct socket_wq and moved SOCKWQ_ASYNC_NOSPACE and SOCKWQ_ASYNC_WAITDATA from struct socket's flags member into that new place. Unfortunately, the new flags field is never initialized properly, at least not for the struct socket_wq instance created in sock_alloc_inode(). One particular issue I encountered because of this is that my GNU Emacs failed to draw anything on my desktop -- i.e. what I got is a transparent window, including the title bar. Bisection lead to the commit mentioned above and further investigation by means of strace told me that Emacs is indeed speaking to my Xorg through an O_ASYNC AF_UNIX socket. This is reproducible 100% of times and the fact that properly initializing the struct socket_wq ->flags fixes the issue leads me to the conclusion that somehow SOCKWQ_ASYNC_WAITDATA got set in the uninitialized ->flags, preventing my Emacs from receiving any SIGIO's due to data becoming available and it got stuck. Make sock_alloc_inode() set the newly created struct socket_wq's ->flags member to zero. Fixes: ceb5d58b2170 ("net: fix sock_wake_async() rcu protection") Signed-off-by: Nicolai Stange Acked-by: Eric Dumazet Signed-off-by: David S. Miller

net: fix uninitialized variable issue

2015-12-15T20:46:48+00:00

msg_iocb needs to be initialized on the recv/recvfrom path. Otherwise afalg will wrongly interpret it as an async call. Cc: stable@vger.kernel.org Reported-by: Harald Freudenberger Signed-off-by: Tadeusz Struk Signed-off-by: David S. Miller

net: fix sock_wake_async() rcu protection

2015-12-01T20:45:05+00:00

Dmitry provided a syzkaller (http://github.com/google/syzkaller) triggering a fault in sock_wake_async() when async IO is requested. Said program stressed af_unix sockets, but the issue is generic and should be addressed in core networking stack. The problem is that by the time sock_wake_async() is called, we should not access the @flags field of 'struct socket', as the inode containing this socket might be freed without further notice, and without RCU grace period. We already maintain an RCU protected structure, "struct socket_wq" so moving SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA into it is the safe route. It also reduces number of cache lines needing dirtying, so might provide a performance improvement anyway. In followup patches, we might move remaining flags (SOCK_NOSPACE, SOCK_PASSCRED, SOCK_PASSSEC) to save 8 bytes and let 'struct socket' being mostly read and let it being shared between cpus. Reported-by: Dmitry Vyukov Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA

2015-12-01T20:45:05+00:00

This patch is a cleanup to make following patch easier to review. Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA from (struct socket)->flags to a (struct socket_wq)->flags to benefit from RCU protection in sock_wake_async() To ease backports, we rename both constants. Two new helpers, sk_set_bit(int nr, struct sock *sk) and sk_clear_bit(int net, struct sock *sk) are added so that following patch can change their implementation. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Drop unlikely before IS_ERR(_OR_NULL)

2015-09-29T13:15:40+00:00

IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it. Acked-by: Neil Horman Signed-off-by: Viresh Kumar Signed-off-by: Jiri Kosina

net: Add a struct net parameter to sock_create_kern

2015-05-11T14:50:17+00:00

This is long overdue, and is part of cleaning up how we allocate kernel sockets that don't reference count struct net. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

tun: Utilize the normal socket network namespace refcounting.

2015-05-11T14:50:16+00:00

There is no need for tun to do the weird network namespace refcounting. The existing network namespace refcounting in tfile has almost exactly the same lifetime. So rewrite the code to use the struct sock network namespace refcounting and remove the unnecessary hand rolled network namespace refcounting and the unncesary tfile->net. This change allows the tun code to directly call sock_put bypassing sock_release and making SOCK_EXTERNALLY_ALLOCATED unnecessary. Remove the now unncessary tun_release so that if anything tries to use the sock_release code path the kernel will oops, and let us know about the bug. The macvtap code already uses it's internal socket this way. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

VFS: net/: d_inode() annotations

2015-04-15T19:06:56+00:00

socket inodes and sunrpc filesystems - inodes owned by that code Signed-off-by: David Howells Signed-off-by: Al Viro

make new_sync_{read,write}() static

2015-04-12T02:29:40+00:00

All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro