kernel/git/stable/linux-stable.git/drivers/net/pppol2tp.c, branch linux-2.6.32.y

l2tp: fix another panic in pppol2tp

2016-03-12T13:25:41+00:00

Commit 3feec9095d1 ("l2tp: Fix oops in pppol2tp_xmit") was backported into 2.6.32.16 to fix a possible null deref in pppol2tp. But the same still exists in pppol2tp_sendmsg() possibly causing the same crash. Note that this bug doesn't appear to have any other impact than crashing the system, as the dereferenced pointer is only used to test a value against a 3-bit mask, so it can hardly be abused for anything except leaking one third of a bit of memory. This issue doesn't exist upstream because the code was replaced in 2.6.35 and the new function l2tp_xmit_skb() performs the appropriate check. Reported-by: Ben Hutchings Signed-off-by: Willy Tarreau

net/l2tp: don't fall back on UDP [get|set]sockopt

2014-12-13T14:16:12+00:00

(commit 3cf521f7dc87c031617fd47e4b7aa2593c2f3daf upstream) The l2tp [get|set]sockopt() code has fallen back to the UDP functions for socket option levels != SOL_PPPOL2TP since day one, but that has never actually worked, since the l2tp socket isn't an inet socket. As David Miller points out: "If we wanted this to work, it'd have to look up the tunnel and then use tunnel->sk, but I wonder how useful that would be" Since this can never have worked so nobody could possibly have depended on that functionality, just remove the broken code and return -EINVAL. Reported-by: Sasha Levin Acked-by: James Chapman Acked-by: David Miller Cc: Phil Turnbull Cc: Vegard Nossum Cc: Willy Tarreau Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds [geissert: adjust file paths and context for 2.6.32] [wt: fixes CVE-2014-4943] Signed-off-by: Willy Tarreau

net: rework recvmsg handler msg_name and msg_namelen logic

2014-05-19T05:54:00+00:00

CVE-2013-7266 BugLink: http://bugs.launchpad.net/bugs/1267081 This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller (back ported from commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c) Signed-off-by: Luis Henriques Acked-by: Andy Whitcroft Acked-by: Stefan Bader Signed-off-by: Tim Gardner Signed-off-by: Willy Tarreau

l2tp: Fix UDP socket reference count bugs in the pppol2tp driver

2011-05-09T22:55:38+00:00

commit c3259c8a7060d480e8eb2166da0a99d6879146b4 upstream. This patch fixes UDP socket refcnt bugs in the pppol2tp driver. A bug can cause a kernel stack trace when a tunnel socket is closed. A way to reproduce the issue is to prepare the UDP socket for L2TP (by opening a tunnel pppol2tp socket) and then close it before any L2TP sessions are added to it. The sequence is Create UDP socket Create tunnel pppol2tp socket to prepare UDP socket for L2TP pppol2tp_connect: session_id=0, peer_session_id=0 L2TP SCCRP control frame received (tunnel_id==0) pppol2tp_recv_core: sock_hold() pppol2tp_recv_core: sock_put L2TP ZLB control frame received (tunnel_id=nnn) pppol2tp_recv_core: sock_hold() pppol2tp_recv_core: sock_put Close tunnel management socket pppol2tp_release: session_id=0, peer_session_id=0 Close UDP socket udp_lib_close: BUG The addition of sock_hold() in pppol2tp_connect() solves the problem. For data frames, two sock_put() calls were added to plug a refcnt leak per received data frame. The ref that is grabbed at the top of pppol2tp_recv_core() must always be released, but this wasn't done for accepted data frames or data frames discarded because of bad UDP checksums. This leak meant that any UDP socket that had passed L2TP data traffic (i.e. L2TP data frames, not just L2TP control frames) using pppol2tp would not be released by the kernel. WARNING: at include/net/sock.h:435 udp_lib_unhash+0x117/0x120() Pid: 1086, comm: openl2tpd Not tainted 2.6.33-rc1 #8 Call Trace: [] ? udp_lib_unhash+0x117/0x120 [] ? warn_slowpath_common+0x71/0xd0 [] ? udp_lib_unhash+0x117/0x120 [] ? warn_slowpath_null+0x13/0x20 [] ? udp_lib_unhash+0x117/0x120 [] ? sk_common_release+0x17/0x90 [] ? inet_release+0x33/0x60 [] ? sock_release+0x10/0x60 [] ? sock_close+0xf/0x30 [] ? __fput+0x52/0x150 [] ? filp_close+0x3e/0x70 [] ? put_files_struct+0x62/0xb0 [] ? do_exit+0x5e7/0x650 [] ? mntput_no_expire+0x13/0x70 [] ? filp_close+0x3e/0x70 [] ? do_group_exit+0x2a/0x70 [] ? sys_exit_group+0x11/0x20 [] ? sysenter_do_call+0x12/0x26 Signed-off-by: James Chapman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

l2tp: Fix oops in pppol2tp_xmit

2010-07-05T18:11:15+00:00

commit 3feec9095d12e311b7d4eb7fe7e5dfa75d4a72a5 upstream. When transmitting L2TP frames, we derive the outgoing interface's UDP checksum hardware assist capabilities from the tunnel dst dev. This can sometimes be NULL, especially when routing protocols are used and routing changes occur. This patch just checks for NULL dst or dev pointers when checking for netdev hardware assist features. BUG: unable to handle kernel NULL pointer dereference at 0000000c IP: [] pppol2tp_xmit+0x341/0x4da [pppol2tp] *pde = 00000000 Oops: 0000 [#1] SMP last sysfs file: /sys/class/net/lo/operstate Modules linked in: pppol2tp pppox ppp_generic slhc ipv6 dummy loop snd_hda_codec_atihdmi snd_hda_intel snd_hda_codec snd_pcm snd_timer snd soundcore snd_page_alloc evdev psmouse serio_raw processor button i2c_piix4 i2c_core ati_agp agpgart pcspkr ext3 jbd mbcache sd_mod ide_pci_generic atiixp ide_core ahci ata_generic floppy ehci_hcd ohci_hcd libata e1000e scsi_mod usbcore nls_base thermal fan thermal_sys [last unloaded: scsi_wait_scan] Pid: 0, comm: swapper Not tainted (2.6.32.8 #1) EIP: 0060:[] EFLAGS: 00010297 CPU: 3 EIP is at pppol2tp_xmit+0x341/0x4da [pppol2tp] EAX: 00000000 EBX: f64d1680 ECX: 000005b9 EDX: 00000000 ESI: f6b91850 EDI: f64d16ac EBP: f6a0c4c0 ESP: f70a9cac DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 Process swapper (pid: 0, ti=f70a8000 task=f70a31c0 task.ti=f70a8000) Stack: 000005a9 000005b9 f734c400 f66652c0 f7352e00 f67dc800 00000000 f6b91800 <0> 000005a3 f70ef6c4 f67dcda9 000005a3 f89b192e 00000246 000005a3 f64d1680 <0> f63633e0 f6363320 f64d1680 f65a7320 f65a7364 f65856c0 f64d1680 f679f02f Call Trace: [] ? ppp_push+0x459/0x50e [ppp_generic] [] ? ppp_xmit_process+0x3b6/0x430 [ppp_generic] [] ? ppp_start_xmit+0x10d/0x120 [ppp_generic] [] ? dev_hard_start_xmit+0x21f/0x2b2 [] ? sch_direct_xmit+0x48/0x10e [] ? dev_queue_xmit+0x263/0x3a6 [] ? ip_finish_output+0x1f7/0x221 [] ? ip_forward_finish+0x2e/0x30 [] ? ip_rcv_finish+0x295/0x2a9 [] ? netif_receive_skb+0x3e9/0x404 [] ? e1000_clean_rx_irq+0x253/0x2fc [e1000e] [] ? e1000_clean+0x63/0x1fc [e1000e] [] ? sched_clock_local+0x15/0x11b [] ? net_rx_action+0x96/0x195 [] ? __do_softirq+0xaa/0x151 [] ? do_softirq+0x31/0x3c [] ? irq_exit+0x26/0x58 [] ? do_IRQ+0x78/0x89 [] ? common_interrupt+0x29/0x30 [] ? native_safe_halt+0x2/0x3 [] ? default_idle+0x55/0x75 [] ? c1e_idle+0xd2/0xd5 [] ? cpu_idle+0x46/0x62 Code: 8d 45 08 f0 ff 45 08 89 6b 08 c7 43 68 7e fb 9c f8 8a 45 24 83 e0 0c 3c 04 75 09 80 63 64 f3 e9 b4 00 00 00 8b 43 18 8b 4c 24 04 <8b> 40 0c 8d 79 11 f6 40 44 0e 8a 43 64 75 51 6a 00 8b 4c 24 08 EIP: [] pppol2tp_xmit+0x341/0x4da [pppol2tp] SS:ESP 0068:f70a9cac CR2: 000000000000000c Signed-off-by: James Chapman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Make setsockopt() optlen be unsigned.

2009-09-30T23:12:20+00:00

This provides safety against negative optlen at the type level instead of depending upon (sometimes non-trivial) checks against this sprinkled all over the the place, in each and every implementation. Based upon work done by Arjan van de Ven and feedback from Linus Torvalds. Signed-off-by: David S. Miller

net: constify remaining proto_ops

2009-09-15T00:03:09+00:00

Signed-off-by: Alexey Dobriyan Signed-off-by: David S. Miller

pppol2tp: calls unregister_pernet_gen_device() at unload time

2009-08-02T19:20:34+00:00

Failure to call unregister_pernet_gen_device() can exhaust memory if module is loaded/unloaded many times. Signed-off-by: Eric Dumazet Acked-by: Cyrill Gorcunov Signed-off-by: David S. Miller

net: skb->dst accessors

2009-06-03T09:51:04+00:00

Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

drivers/net: replace BUG() with BUG_ON() if possible

2009-04-13T22:44:36+00:00

Signed-off-by: Alexander Beregalov Signed-off-by: David S. Miller