linux-stable.git/net/l2tp/l2tp_debugfs.c, branch linux-3.2.y Linux kernel stable tree l2tp: take reference on sessions being dumped 2017-07-18T17:38:41+00:00 Guillaume Nault g.nault@alphalink.fr 2017-04-03T10:03:13+00:00 2b846c841db527fe9afff23b70c265b1809cd792 commit e08293a4ccbcc993ded0fdc46f1e57926b833d63 upstream. Take a reference on the sessions returned by l2tp_session_find_nth() (and rename it l2tp_session_get_nth() to reflect this change), so that caller is assured that the session isn't going to disappear while processing it. For procfs and debugfs handlers, the session is held in the .start() callback and dropped in .show(). Given that pppol2tp_seq_session_show() dereferences the associated PPPoL2TP socket and that l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to call the session's .ref() callback to prevent the socket from going away from under us. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e08293a4ccbcc993ded0fdc46f1e57926b833d63 upstream.

Take a reference on the sessions returned by l2tp_session_find_nth()
(and rename it l2tp_session_get_nth() to reflect this change), so that
caller is assured that the session isn't going to disappear while
processing it.

For procfs and debugfs handlers, the session is held in the .start()
callback and dropped in .show(). Given that pppol2tp_seq_session_show()
dereferences the associated PPPoL2TP socket and that
l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to
call the session's .ref() callback to prevent the socket from going
away from under us.

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info")
Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fix return values of l2tp_dfs_seq_open() 2011-06-05T21:11:09+00:00 Al Viro viro@ZenIV.linux.org.uk 2011-06-05T00:54:03+00:00 b8f07a063163f8216cd891c5b007e839a56b6d93 More fallout from struct net lifetime rules review: PTR_ERR() is *already* negative and failing ->open() should return negatives on failure. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
More fallout from struct net lifetime rules review: PTR_ERR() is *already*
negative and failing ->open() should return negatives on failure.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l2tp: kzalloc with swapped params in l2tp_dfs_seq_open 2010-11-01T13:56:02+00:00 Dr. David Alan Gilbert linux@treblig.org 2010-10-31T07:26:03+00:00 6f9b901823aafd14a84ae27f61ff28bafed01260 'sparse' spotted that the parameters to kzalloc in l2tp_dfs_seq_open were swapped. Tested on current git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git at 1792f17b7210280a3d7ff29da9614ba779cfcedb build, boots and I can see that directory, but there again I could see /sys/kernel/debug/l2tp with it swapped; I don't have any l2tp in use. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
  'sparse' spotted that the parameters to kzalloc in l2tp_dfs_seq_open
were swapped.

Tested on current git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
at 1792f17b7210280a3d7ff29da9614ba779cfcedb  build, boots and I can see that directory,
but there again I could see /sys/kernel/debug/l2tp with it swapped; I don't have
any l2tp in use.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/l2tp/l2tp_debugfs.c: Convert NIPQUAD to %pI4 2010-04-15T22:37:13+00:00 Joe Perches joe@perches.com 2010-04-15T22:37:13+00:00 a4fbf8415c462208e77251779d80dbc81914cebd Signed-off-by: Joe Perches <joe@perches.com> Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l2tp: Add debugfs files for dumping l2tp debug info 2010-04-03T21:56:07+00:00 James Chapman jchapman@katalix.com 2010-04-02T06:19:33+00:00 0ad6614048cf722e4d27909665b4846805357f1b The existing pppol2tp driver exports debug info to /proc/net/pppol2tp. Rather than adding info to that file for the new functionality added in this patch series, we add new files in debugfs, leaving the old /proc file for backwards compatibility (L2TPv2 only). Currently only one file is provided: l2tp/tunnels, which lists internal debug info for all l2tp tunnels and sessions. More files may be added later. The info is for debug and problem analysis only - userspace apps should use netlink to obtain status about l2tp tunnels and sessions. Although debugfs does not support net namespaces, the tunnels and sessions dumped in l2tp/tunnels are only those in the net namespace of the process reading the file. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The existing pppol2tp driver exports debug info to
/proc/net/pppol2tp. Rather than adding info to that file for the new
functionality added in this patch series, we add new files in debugfs,
leaving the old /proc file for backwards compatibility (L2TPv2 only).

Currently only one file is provided: l2tp/tunnels, which lists
internal debug info for all l2tp tunnels and sessions. More files may
be added later. The info is for debug and problem analysis only -
userspace apps should use netlink to obtain status about l2tp tunnels
and sessions.

Although debugfs does not support net namespaces, the tunnels and
sessions dumped in l2tp/tunnels are only those in the net namespace of
the process reading the file.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>