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2018-07-27l2tp: drop ->mru from struct l2tp_sessionGuillaume Nault5-50/+8
This field is not used. Treat PPPIOC*MRU the same way as PPPIOC*FLAGS: "get" requests return 0, while "set" requests vadidate the user supplied pointer but discard its value. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: drop ->flags from struct pppol2tp_sessionGuillaume Nault1-11/+2
This field is not used. Keep validating user input in PPPIOCSFLAGS. Even though we discard the value, it would look wrong to succeed if an invalid address was passed from userspace. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: ignore L2TP_ATTR_VLAN_ID netlink attributeGuillaume Nault2-4/+0
The value of this attribute is never used. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: ignore L2TP_ATTR_DATA_SEQ netlink attributeGuillaume Nault3-17/+1
The value of this attribute is never used. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-26l2tp: remove ->recv_payload_hookGuillaume Nault5-39/+18
The tunnel reception hook is only used by l2tp_ppp for skipping PPP framing bytes. This is a session specific operation, but once a PPP session sets ->recv_payload_hook on its tunnel, all frames received by the tunnel will enter pppol2tp_recv_payload_hook(), including those targeted at Ethernet sessions (an L2TPv3 tunnel can multiplex PPP and Ethernet sessions). So this mechanism is wrong, and uselessly complex. Let's just move this functionality to the pppol2tp rx handler and drop ->recv_payload_hook. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24l2tp: remove trailing newlineStephen Hemminger1-1/+0
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07ipv6: fold sockcm_cookie into ipcm6_cookieWillem de Bruijn1-4/+2
ipcm_cookie includes sockcm_cookie. Do the same for ipcm6_cookie. This reduces the number of arguments that need to be passed around, applies ipcm6_init to all cookie fields at once and reduces code differentiation between ipv4 and ipv6. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07ipv6: ipcm6_cookie initializerWillem de Bruijn1-3/+1
Initialize the cookie in one location to reduce code duplication and avoid bugs from inconsistent initialization, such as that fixed in commit 9887cba19978 ("ip: limit use of gso_size to udp"). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-03Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-3/+3
Simple overlapping changes in stmmac driver. Adjust skb_gro_flush_final_remcsum function signature to make GRO list changes in net-next, as per Stephen Rothwell's example merge resolution. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLLLinus Torvalds3-3/+3
The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28l2tp: define helper for parsing struct sockaddr_pppol2tp*Guillaume Nault1-70/+103
'sockaddr_len' is checked against various values when entering pppol2tp_connect(), to verify its validity. It is used again later, to find out which sockaddr structure was passed from user space. This patch combines these two operations into one new function in order to simplify pppol2tp_connect(). A new structure, l2tp_connect_info, is used to pass sockaddr data back to pppol2tp_connect(), to avoid passing too many parameters to l2tp_sockaddr_get_info(). Also, the first parameter is void* in order to avoid casting between all sockaddr_* structures manually. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: make l2tp_xmit_core() return voidGuillaume Nault1-4/+2
It always returns 0, and nobody reads the return value anyway. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: avoid duplicate l2tp_pernet() callsGuillaume Nault1-2/+1
Replace 'l2tp_pernet(tunnel->l2tp_net)' with 'pn', which has been set on the preceding line. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: don't export l2tp_tunnel_closeall()Guillaume Nault2-3/+1
This function is only used in l2tp_core.c. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: don't export l2tp_session_queue_purge()Guillaume Nault2-3/+1
This function is only used in l2tp_core.c. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: remove l2tp_tunnel_priv()Guillaume Nault1-7/+0
This function, and the associated .priv field, are unused. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: remove .show from struct l2tp_tunnelGuillaume Nault2-6/+0
This callback has never been implemented. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: remove pppol2tp_session_close()Guillaume Nault1-7/+0
l2tp_core.c verifies that ->session_close() is defined before calling it. There's no need for a stub. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-15l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()Guillaume Nault1-1/+1
pppol2tp_tunnel_ioctl() can act on an L2TPv3 tunnel, in which case 'session' may be an Ethernet pseudo-wire. However, pppol2tp_session_ioctl() expects a PPP pseudo-wire, as it assumes l2tp_session_priv() points to a pppol2tp_session structure. For an Ethernet pseudo-wire l2tp_session_priv() points to an l2tp_eth_sess structure instead, making pppol2tp_session_ioctl() access invalid memory. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-15l2tp: reject creation of non-PPP sessions on L2TPv2 tunnelsGuillaume Nault1-0/+6
The /proc/net/pppol2tp handlers (pppol2tp_seq_*()) iterate over all L2TPv2 tunnels, and rightfully expect that only PPP sessions can be found there. However, l2tp_netlink accepts creating Ethernet sessions regardless of the underlying tunnel version. This confuses pppol2tp_seq_session_show(), which expects that l2tp_session_priv() returns a pppol2tp_session structure. When the session is an Ethernet pseudo-wire, a struct l2tp_eth_sess is returned instead. This leads to invalid memory access when pppol2tp_session_get_sock() later tries to dereference ps->sk. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14l2tp: clean up stale tunnel or session in pppol2tp_connect's error pathGuillaume Nault1-0/+10
pppol2tp_connect() may create a tunnel or a session. Remove them in case of error. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14l2tp: prevent pppol2tp_connect() from creating kernel socketsGuillaume Nault1-0/+9
If 'fd' is negative, l2tp_tunnel_create() creates a tunnel socket using the configuration passed in 'tcfg'. Currently, pppol2tp_connect() sets the relevant fields to zero, tricking l2tp_tunnel_create() into setting up an unusable kernel socket. We can't set 'tcfg' with the required fields because there's no way to get them from the current connect() parameters. So let's restrict kernel sockets creation to the netlink API, which is the original use case. Fixes: 789a4a2c61d8 ("l2tp: Add support for static unmanaged L2TPv3 tunnels") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14l2tp: only accept PPP sessions in pppol2tp_connect()Guillaume Nault1-0/+6
l2tp_session_priv() returns a struct pppol2tp_session pointer only for PPPoL2TP sessions. In particular, if the session is an L2TP_PWTYPE_ETH pseudo-wire, l2tp_session_priv() returns a pointer to an l2tp_eth_sess structure, which is much smaller than struct pppol2tp_session. This leads to invalid memory dereference when trying to lock ps->sk_lock. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14l2tp: fix pseudo-wire type for sessions created by pppol2tp_connect()Guillaume Nault1-0/+1
Define cfg.pw_type so that the new session is created with its .pwtype field properly set (L2TP_PWTYPE_PPP). Not setting the pseudo-wire type had several annoying effects: * Invalid value returned in the L2TP_ATTR_PW_TYPE attribute when dumping sessions with the netlink API. * Impossibility to delete the session using the netlink API (because l2tp_nl_cmd_session_delete() gets the deletion callback function from an array indexed by the session's pseudo-wire type). Also, there are several cases where we should check a session's pseudo-wire type. For example, pppol2tp_connect() should refuse to connect a session that is not PPPoL2TP, but that requires the session's .pwtype field to be properly set. Fixes: f7faffa3ff8e ("l2tp: Add L2TPv3 protocol support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2-33/+43
Pull networking updates from David Miller: 1) Add Maglev hashing scheduler to IPVS, from Inju Song. 2) Lots of new TC subsystem tests from Roman Mashak. 3) Add TCP zero copy receive and fix delayed acks and autotuning with SO_RCVLOWAT, from Eric Dumazet. 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard Brouer. 5) Add ttl inherit support to vxlan, from Hangbin Liu. 6) Properly separate ipv6 routes into their logically independant components. fib6_info for the routing table, and fib6_nh for sets of nexthops, which thus can be shared. From David Ahern. 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP messages from XDP programs. From Nikita V. Shirokov. 8) Lots of long overdue cleanups to the r8169 driver, from Heiner Kallweit. 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau. 10) Add traffic condition monitoring to iwlwifi, from Luca Coelho. 11) Plumb extack down into fib_rules, from Roopa Prabhu. 12) Add Flower classifier offload support to igb, from Vinicius Costa Gomes. 13) Add UDP GSO support, from Willem de Bruijn. 14) Add documentation for eBPF helpers, from Quentin Monnet. 15) Add TLS tx offload to mlx5, from Ilya Lesokhin. 16) Allow applications to be given the number of bytes available to read on a socket via a control message returned from recvmsg(), from Soheil Hassas Yeganeh. 17) Add x86_32 eBPF JIT compiler, from Wang YanQing. 18) Add AF_XDP sockets, with zerocopy support infrastructure as well. From Björn Töpel. 19) Remove indirect load support from all of the BPF JITs and handle these operations in the verifier by translating them into native BPF instead. From Daniel Borkmann. 20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha. 21) Allow XDP programs to do lookups in the main kernel routing tables for forwarding. From David Ahern. 22) Allow drivers to store hardware state into an ELF section of kernel dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy. 23) Various RACK and loss detection improvements in TCP, from Yuchung Cheng. 24) Add TCP SACK compression, from Eric Dumazet. 25) Add User Mode Helper support and basic bpfilter infrastructure, from Alexei Starovoitov. 26) Support ports and protocol values in RTM_GETROUTE, from Roopa Prabhu. 27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard Brouer. 28) Add lots of forwarding selftests, from Petr Machata. 29) Add generic network device failover driver, from Sridhar Samudrala. * ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits) strparser: Add __strp_unpause and use it in ktls. rxrpc: Fix terminal retransmission connection ID to include the channel net: hns3: Optimize PF CMDQ interrupt switching process net: hns3: Fix for VF mailbox receiving unknown message net: hns3: Fix for VF mailbox cannot receiving PF response bnx2x: use the right constant Revert "net: sched: cls: Fix offloading when ingress dev is vxlan" net: dsa: b53: Fix for brcm tag issue in Cygnus SoC enic: fix UDP rss bits netdev-FAQ: clarify DaveM's position for stable backports rtnetlink: validate attributes in do_setlink() mlxsw: Add extack messages for port_{un, }split failures netdevsim: Add extack error message for devlink reload devlink: Add extack to reload and port_{un, }split operations net: metrics: add proper netlink validation ipmr: fix error path when ipmr_new_table fails ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds net: hns3: remove unused hclgevf_cfg_func_mta_filter netfilter: provide udp*_lib_lookup for nf_tproxy qed*: Utilize FW 8.37.2.0 ...
2018-06-05l2tp: fix refcount leakage on PPPoL2TP socketsGuillaume Nault1-18/+17
Commit d02ba2a6110c ("l2tp: fix race in pppol2tp_release with session object destroy") tried to fix a race condition where a PPPoL2TP socket would disappear while the L2TP session was still using it. However, it missed the root issue which is that an L2TP session may accept to be reconnected if its associated socket has entered the release process. The tentative fix makes the session hold the socket it is connected to. That saves the kernel from crashing, but introduces refcount leakage, preventing the socket from completing the release process. Once stalled, everything the socket depends on can't be released anymore, including the L2TP session and the l2tp_ppp module. The root issue is that, when releasing a connected PPPoL2TP socket, the session's ->sk pointer (RCU-protected) is reset to NULL and we have to wait for a grace period before destroying the socket. The socket drops the session in its ->sk_destruct callback function, so the session will exist until the last reference on the socket is dropped. Therefore, there is a time frame where pppol2tp_connect() may accept reconnecting a session, as it only checks ->sk to figure out if the session is connected. This time frame is shortened by the fact that pppol2tp_release() calls l2tp_session_delete(), making the session unreachable before resetting ->sk. However, pppol2tp_connect() may grab the session before it gets unhashed by l2tp_session_delete(), but it may test ->sk after the later got reset. The race is not so hard to trigger and syzbot found a pretty reliable reproducer: https://syzkaller.appspot.com/bug?id=418578d2a4389074524e04d641eacb091961b2cf Before d02ba2a6110c, another race could let pppol2tp_release() overwrite the ->__sk pointer of an L2TP session, thus tricking pppol2tp_put_sk() into calling sock_put() on a socket that is different than the one for which pppol2tp_release() was originally called. To get there, we had to trigger the race described above, therefore having one PPPoL2TP socket being released, while the session it is connected to is reconnecting to a different PPPoL2TP socket. When releasing this new socket fast enough, pppol2tp_release() overwrites the session's ->__sk pointer with the address of the new socket, before the first pppol2tp_put_sk() call gets scheduled. Then the pppol2tp_put_sk() call invoked by the original socket will sock_put() the new socket, potentially dropping its last reference. When the second pppol2tp_put_sk() finally runs, its socket has already been freed. With d02ba2a6110c, the session takes a reference on both sockets. Furthermore, the session's ->sk pointer is reset in the pppol2tp_session_close() callback function rather than in pppol2tp_release(). Therefore, ->__sk can't be overwritten and pppol2tp_put_sk() is called only once (l2tp_session_delete() will only run pppol2tp_session_close() once, to protect the session against concurrent deletion requests). Now pppol2tp_put_sk() will properly sock_put() the original socket, but the new socket will remain, as l2tp_session_delete() prevented the release process from completing. Here, we don't depend on the ->__sk race to trigger the bug. Getting into the pppol2tp_connect() race is enough to leak the reference, no matter when new socket is released. So it all boils down to pppol2tp_connect() failing to realise that the session has already been connected. This patch drops the unneeded extra reference counting (mostly reverting d02ba2a6110c) and checks that neither ->sk nor ->__sk is set before allowing a session to be connected. Fixes: d02ba2a6110c ("l2tp: fix race in pppol2tp_release with session object destroy") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-04Merge branch 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds3-3/+3
Pull aio updates from Al Viro: "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly. The only thing I'm holding back for a day or so is Adam's aio ioprio - his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case), but let it sit in -next for decency sake..." * 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) aio: sanitize the limit checking in io_submit(2) aio: fold do_io_submit() into callers aio: shift copyin of iocb into io_submit_one() aio_read_events_ring(): make a bit more readable aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way aio: take list removal to (some) callers of aio_complete() aio: add missing break for the IOCB_CMD_FDSYNC case random: convert to ->poll_mask timerfd: convert to ->poll_mask eventfd: switch to ->poll_mask pipe: convert to ->poll_mask crypto: af_alg: convert to ->poll_mask net/rxrpc: convert to ->poll_mask net/iucv: convert to ->poll_mask net/phonet: convert to ->poll_mask net/nfc: convert to ->poll_mask net/caif: convert to ->poll_mask net/bluetooth: convert to ->poll_mask net/sctp: convert to ->poll_mask net/tipc: convert to ->poll_mask ...
2018-05-26net: convert datagram_poll users tp ->poll_maskChristoph Hellwig3-3/+3
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-16proc: introduce proc_create_net{,_data}Christoph Hellwig1-20/+2
Variants of proc_create{,_data} that directly take a struct seq_operations and deal with network namespaces in ->open and ->release. All callers of proc_create + seq_open_net converted over, and seq_{open,release}_net are removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-04-27l2tp: consistent reference counting in procfs and debufsGuillaume Nault2-15/+26
The 'pppol2tp' procfs and 'l2tp/tunnels' debugfs files handle reference counting of sessions differently than for tunnels. For consistency, use the same mechanism for handling both sessions and tunnels. That is, drop the reference on the previous session just before looking up the next one (rather than in .show()). If necessary (if dump stops before *_next_session() returns NULL), drop the last reference in .stop(). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-23l2tp: check sockaddr length in pppol2tp_connect()Guillaume Nault1-0/+7
Check sockaddr_len before dereferencing sp->sa_protocol, to ensure that it actually points to valid data. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Reported-by: syzbot+a70ac890b23b1bf29f5c@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-22l2tp: fix {pppol2tp, l2tp_dfs}_seq_stop() in case of seq_file overflowGuillaume Nault2-2/+8
Commit 0e0c3fee3a59 ("l2tp: hold reference on tunnels printed in pppol2tp proc file") assumed that if pppol2tp_seq_stop() was called with non-NULL private data (the 'v' pointer), then pppol2tp_seq_start() would not be called again. It turns out that this isn't guaranteed, and overflowing the seq_file's buffer in pppol2tp_seq_show() is a way to get into this situation. Therefore, pppol2tp_seq_stop() needs to reset pd->tunnel, so that pppol2tp_seq_start() won't drop a reference again if it gets called. We also have to clear pd->session, because the rest of the code expects a non-NULL tunnel when pd->session is set. The l2tp_debugfs module has the same issue. Fix it in the same way. Fixes: 0e0c3fee3a59 ("l2tp: hold reference on tunnels printed in pppol2tp proc file") Fixes: f726214d9b23 ("l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs fileGuillaume Nault3-23/+13
Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe against concurrent tunnel deletion. Use the same mechanism as in l2tp_ppp.c for dropping the reference taken by l2tp_tunnel_get_nth(). That is, drop the reference just before looking up the next tunnel. In case of error, drop the last accessed tunnel in l2tp_dfs_seq_stop(). That was the last use of l2tp_tunnel_find_nth(). Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13l2tp: hold reference on tunnels printed in pppol2tp proc fileGuillaume Nault1-7/+17
Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe against concurrent tunnel deletion. Unlike sessions, we can't drop the reference held on tunnels in pppol2tp_seq_show(). Tunnels are reused across several calls to pppol2tp_seq_start() when iterating over sessions. These iterations need the tunnel for accessing the next session. Therefore the only safe moment for dropping the reference is just before searching for the next tunnel. Normally, the last invocation of pppol2tp_next_tunnel() doesn't find any new tunnel, so it drops the last tunnel without taking any new reference. However, in case of error, pppol2tp_seq_stop() is called directly, so we have to drop the reference there. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13l2tp: hold reference on tunnels in netlink dumpsGuillaume Nault3-3/+30
l2tp_tunnel_find_nth() is unsafe: no reference is held on the returned tunnel, therefore it can be freed whenever the caller uses it. This patch defines l2tp_tunnel_get_nth() which works similarly, but also takes a reference on the returned tunnel. The caller then has to drop it after it stops using the tunnel. Convert netlink dumps to make them safe against concurrent tunnel deletion. 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>
2018-04-11l2tp: fix race in duplicate tunnel detectionGuillaume Nault3-28/+14
We can't use l2tp_tunnel_find() to prevent l2tp_nl_cmd_tunnel_create() from creating a duplicate tunnel. A tunnel can be concurrently registered after l2tp_tunnel_find() returns. Therefore, searching for duplicates must be done at registration time. Finally, remove l2tp_tunnel_find() entirely as it isn't use anywhere anymore. 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>
2018-04-11l2tp: fix races in tunnel creationGuillaume Nault4-110/+110
l2tp_tunnel_create() inserts the new tunnel into the namespace's tunnel list and sets the socket's ->sk_user_data field, before returning it to the caller. Therefore, there are two ways the tunnel can be accessed and freed, before the caller even had the opportunity to take a reference. In practice, syzbot could crash the module by closing the socket right after a new tunnel was returned to pppol2tp_create(). This patch moves tunnel registration out of l2tp_tunnel_create(), so that the caller can safely hold a reference before publishing the tunnel. This second step is done with the new l2tp_tunnel_register() function, which is now responsible for associating the tunnel to its socket and for inserting it into the namespace's list. While moving the code to l2tp_tunnel_register(), a few modifications have been done. First, the socket validation tests are done in a helper function, for clarity. Also, modifying the socket is now done after having inserted the tunnel to the namespace's tunnels list. This will allow insertion to fail, without having to revert theses modifications in the error path (a followup patch will check for duplicate tunnels before insertion). Either the socket is a kernel socket which we control, or it is a user-space socket for which we have a reference on the file descriptor. In any case, the socket isn't going to be closed from under us. Reported-by: syzbot+fbeeb5c3b538e8545644@syzkaller.appspotmail.com Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai2-2/+0
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26net: Use octal not symbolic permissionsJoe Perches1-1/+1
Prefer the direct use of octal for permissions. Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace and some typing. Miscellanea: o Whitespace neatening around these conversions. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-25/+24
Fun set of conflict resolutions here... For the mac80211 stuff, these were fortunately just parallel adds. Trivially resolved. In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the function phy_disable_interrupts() earlier in the file, whilst in 'net-next' the phy_error() call from this function was removed. In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the 'rt_table_id' member of rtable collided with a bug fix in 'net' that added a new struct member "rt_mtu_locked" which needs to be copied over here. The mlxsw driver conflict consisted of net-next separating the span code and definitions into separate files, whilst a 'net' bug fix made some changes to that moved code. The mlx5 infiniband conflict resolution was quite non-trivial, the RDMA tree's merge commit was used as a guide here, and here are their notes: ==================== Due to bug fixes found by the syzkaller bot and taken into the for-rc branch after development for the 4.17 merge window had already started being taken into the for-next branch, there were fairly non-trivial merge issues that would need to be resolved between the for-rc branch and the for-next branch. This merge resolves those conflicts and provides a unified base upon which ongoing development for 4.17 can be based. Conflicts: drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f9524 (IB/mlx5: Fix cleanup order on unload) added to for-rc and commit b5ca15ad7e61 (IB/mlx5: Add proper representors support) add as part of the devel cycle both needed to modify the init/de-init functions used by mlx5. To support the new representors, the new functions added by the cleanup patch needed to be made non-static, and the init/de-init list added by the representors patch needed to be modified to match the init/de-init list changes made by the cleanup patch. Updates: drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function prototypes added by representors patch to reflect new function names as changed by cleanup patch drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init stage list to match new order from cleanup patch ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-17net: Convert l2tp_net_opsKirill Tkhai1-0/+1
Init method is rather simple. Exit method queues del_work for every tunnel from per-net list. This seems to be safe to be marked async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-12l2tp: fix races with ipv4-mapped ipv6 addressesPaolo Abeni2-23/+18
The l2tp_tunnel_create() function checks for v4mapped ipv6 sockets and cache that flag, so that l2tp core code can reusing it at xmit time. If the socket is provided by the userspace, the connection status of the tunnel sockets can change between the tunnel creation and the xmit call, so that syzbot is able to trigger the following splat: BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:192 [inline] BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264 Read of size 8 at addr ffff8801bd949318 by task syz-executor4/23448 CPU: 0 PID: 23448 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #65 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23c/0x360 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 ip6_dst_idev include/net/ip6_fib.h:192 [inline] ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264 inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139 l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline] l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148 pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 __sys_sendmsg+0xe5/0x210 net/socket.c:2080 SYSC_sendmsg net/socket.c:2091 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2087 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f819593cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f819593d6d4 RCX: 0000000000453e69 RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000004 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004c3 R14: 00000000006f72e8 R15: 0000000000000000 This change addresses the issues: * explicitly checking for TCP_ESTABLISHED for user space provided sockets * dropping the v4mapped flag usage - it can become outdated - and explicitly invoking ipv6_addr_v4mapped() instead The issue is apparently there since ancient times. v1 -> v2: (many thanks to Guillaume) - with csum issue introduced in v1 - replace pr_err with pr_debug - fix build issue with IPV6 disabled - move l2tp_sk_is_v4mapped in l2tp_core.c v2 -> v3: - don't update inet_daddr for v4mapped address, unneeded - drop rendundant check at creation time Reported-and-tested-by: syzbot+92fa328176eb07e4ac1a@syzkaller.appspotmail.com Fixes: 3557baabf280 ("[L2TP]: PPP over L2TP driver core") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-07l2tp: do not accept arbitrary socketsEric Dumazet1-2/+6
syzkaller found an issue caused by lack of sufficient checks in l2tp_tunnel_create() RAW sockets can not be considered as UDP ones for instance. In another patch, we shall replace all pr_err() by less intrusive pr_debug() so that syzkaller can find other bugs faster. Acked-by: Guillaume Nault <g.nault@alphalink.fr> Acked-by: James Chapman <jchapman@katalix.com> ================================================================== BUG: KASAN: slab-out-of-bounds in setup_udp_tunnel_sock+0x3ee/0x5f0 net/ipv4/udp_tunnel.c:69 dst_release: dst:00000000d53d0d0f refcnt:-1 Write of size 1 at addr ffff8801d013b798 by task syz-executor3/6242 CPU: 1 PID: 6242 Comm: syz-executor3 Not tainted 4.16.0-rc2+ #253 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:412 __asan_report_store1_noabort+0x17/0x20 mm/kasan/report.c:435 setup_udp_tunnel_sock+0x3ee/0x5f0 net/ipv4/udp_tunnel.c:69 l2tp_tunnel_create+0x1354/0x17f0 net/l2tp/l2tp_core.c:1596 pppol2tp_connect+0x14b1/0x1dd0 net/l2tp/l2tp_ppp.c:707 SYSC_connect+0x213/0x4a0 net/socket.c:1640 SyS_connect+0x24/0x30 net/socket.c:1621 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller5-166/+77
All of the conflicts were cases of overlapping changes. In net/core/devlink.c, we have to make care that the resouce size_params have become a struct member rather than a pointer to such an object. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-27net: Convert /proc creating and destroying pernet_operationsKirill Tkhai1-0/+1
These pernet_operations just create and destroy /proc entries, and they can safely marked as async: pppoe_net_ops vlan_net_ops canbcm_pernet_ops kcm_net_ops pfkey_net_ops pppol2tp_net_ops phonet_net_ops Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26l2tp: fix tunnel lookup use-after-free raceJames Chapman1-7/+7
l2tp_tunnel_get walks the tunnel list to find a matching tunnel instance and if a match is found, its refcount is increased before returning the tunnel pointer. But when tunnel objects are destroyed, they are on the tunnel list after their refcount hits zero. Fix this by moving the code that removes the tunnel from the tunnel list from the tunnel socket destructor into in the l2tp_tunnel_delete path, before the tunnel refcount is decremented. refcount_t: increment on 0; use-after-free. WARNING: CPU: 3 PID: 13507 at lib/refcount.c:153 refcount_inc+0x47/0x50 Modules linked in: CPU: 3 PID: 13507 Comm: syzbot_6e6a5ec8 Not tainted 4.16.0-rc2+ #36 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:refcount_inc+0x47/0x50 RSP: 0018:ffff8800136ffb20 EFLAGS: 00010286 RAX: dffffc0000000008 RBX: ffff880017068e68 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: ffff88001a59f6d8 RDI: ffff88001a59f6d8 RBP: ffff8800136ffb28 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8800136ffab0 R11: 0000000000000000 R12: ffff880017068e50 R13: 0000000000000000 R14: ffff8800174da800 R15: 0000000000000004 FS: 00007f403ab1e700(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000205fafd2 CR3: 0000000016770000 CR4: 00000000000006e0 Call Trace: l2tp_tunnel_get+0x2dd/0x4e0 pppol2tp_connect+0x428/0x13c0 ? pppol2tp_session_create+0x170/0x170 ? __might_fault+0x115/0x1d0 ? lock_downgrade+0x860/0x860 ? __might_fault+0xe5/0x1d0 ? security_socket_connect+0x8e/0xc0 SYSC_connect+0x1b6/0x310 ? SYSC_bind+0x280/0x280 ? __do_page_fault+0x5d1/0xca0 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 SyS_connect+0x29/0x30 ? SyS_accept+0x40/0x40 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f403a42f259 RSP: 002b:00007f403ab1dee8 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00000000205fafe4 RCX: 00007f403a42f259 RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 RBP: 00007f403ab1df20 R08: 00007f403ab1e700 R09: 0000000000000000 R10: 00007f403ab1e700 R11: 0000000000000296 R12: 0000000000000000 R13: 00007ffc81906cbf R14: 0000000000000000 R15: 00007f403ab2b040 Code: 3b ff 5b 5d c3 e8 ca 5f 3b ff 80 3d 49 8e 66 04 00 75 ea e8 bc 5f 3b ff 48 c7 c7 60 69 64 85 c6 05 34 8e 66 04 01 e8 59 49 15 ff <0f> 0b eb ce 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 49 Fixes: f8ccac0e44934 ("l2tp: put tunnel socket release on a workqueue") Reported-and-tested-by: syzbot+19c09769f14b48810113@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+347bd5acde002e353a36@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+6e6a5ec8de31a94cd015@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+9df43faf09bd400f2993@syzkaller.appspotmail.com Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26l2tp: fix race in pppol2tp_release with session object destroyJames Chapman1-25/+27
pppol2tp_release uses call_rcu to put the final ref on its socket. But the session object doesn't hold a ref on the session socket so may be freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by having the session hold a ref on its socket until the session is destroyed. It is this ref that is dropped via call_rcu. Sessions are also deleted via l2tp_tunnel_closeall. This must now also put the final ref via call_rcu. So move the call_rcu call site into pppol2tp_session_close so that this happens in both destroy paths. A common destroy path should really be implemented, perhaps with l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release does, but this will be looked at later. ODEBUG: activate active (active state 1) object type: rcu_head hint: (null) WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220 Modules linked in: CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:debug_print_object+0x166/0x220 RSP: 0018:ffff880013647a00 EFLAGS: 00010082 RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0 RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0 Call Trace: debug_object_activate+0x38b/0x530 ? debug_object_assert_init+0x3b0/0x3b0 ? __mutex_unlock_slowpath+0x85/0x8b0 ? pppol2tp_session_destruct+0x110/0x110 __call_rcu.constprop.66+0x39/0x890 ? __call_rcu.constprop.66+0x39/0x890 call_rcu_sched+0x17/0x20 pppol2tp_release+0x2c7/0x440 ? fcntl_setlk+0xca0/0xca0 ? sock_alloc_file+0x340/0x340 sock_release+0x92/0x1e0 sock_close+0x1b/0x20 __fput+0x296/0x6e0 ____fput+0x1a/0x20 task_work_run+0x127/0x1a0 do_exit+0x7f9/0x2ce0 ? SYSC_connect+0x212/0x310 ? mm_update_next_owner+0x690/0x690 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 do_group_exit+0x10d/0x330 ? do_group_exit+0x330/0x330 SyS_exit_group+0x22/0x30 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f362e471259 RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259 RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000 RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000 Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e 8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 Fixes: ee40fb2e1eb5b ("l2tp: protect sock pointer of struct pppol2tp_session with RCU") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26l2tp: fix races with tunnel socket closeJames Chapman4-116/+42
The tunnel socket tunnel->sock (struct sock) is accessed when preparing a new ppp session on a tunnel at pppol2tp_session_init. If the socket is closed by a thread while another is creating a new session, the threads race. In pppol2tp_connect, the tunnel object may be created if the pppol2tp socket is associated with the special session_id 0 and the tunnel socket is looked up using the provided fd. When handling this, pppol2tp_connect cannot sock_hold the tunnel socket to prevent it being destroyed during pppol2tp_connect since this may itself may race with the socket being destroyed. Doing sockfd_lookup in pppol2tp_connect isn't sufficient to prevent tunnel->sock going away either because a given tunnel socket fd may be reused between calls to pppol2tp_connect. Instead, have l2tp_tunnel_create sock_hold the tunnel socket before it does sockfd_put. This ensures that the tunnel's socket is always extant while the tunnel object exists. Hold a ref on the socket until the tunnel is destroyed and ensure that all tunnel destroy paths go through a common function (l2tp_tunnel_delete) since this will do the final sock_put to release the tunnel socket. Since the tunnel's socket is now guaranteed to exist if the tunnel exists, we no longer need to use sockfd_lookup via l2tp_sock_to_tunnel to derive the tunnel from the socket since this is always sk_user_data. Also, sessions no longer sock_hold the tunnel socket since sessions already hold a tunnel ref and the tunnel sock will not be freed until the tunnel is freed. Removing these sock_holds in l2tp_session_register avoids a possible sock leak in the pppol2tp_connect error path if l2tp_session_register succeeds but attaching a ppp channel fails. The pppol2tp_connect error path could have been fixed instead and have the sock ref dropped when the session is freed, but doing a sock_put of the tunnel socket when the session is freed would require a new session_free callback. It is simpler to just remove the sock_hold of the tunnel socket in l2tp_session_register, now that the tunnel socket lifetime is guaranteed. Finally, some init code in l2tp_tunnel_create is reordered to ensure that the new tunnel object's refcount is set and the tunnel socket ref is taken before the tunnel socket destructor callbacks are set. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Modules linked in: CPU: 0 PID: 4360 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #34 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:pppol2tp_session_init+0x1d6/0x500 RSP: 0018:ffff88001377fb40 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: ffff88001636a940 RCX: ffffffff84836c1d RDX: 0000000000000045 RSI: 0000000055976744 RDI: 0000000000000228 RBP: ffff88001377fb60 R08: ffffffff84836bc8 R09: 0000000000000002 R10: ffff88001377fab8 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88001636aac8 R14: ffff8800160f81c0 R15: 1ffff100026eff76 FS: 00007ffb3ea66700(0000) GS:ffff88001a400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000016261000 CR4: 00000000000006f0 Call Trace: pppol2tp_connect+0xd18/0x13c0 ? pppol2tp_session_create+0x170/0x170 ? __might_fault+0x115/0x1d0 ? lock_downgrade+0x860/0x860 ? __might_fault+0xe5/0x1d0 ? security_socket_connect+0x8e/0xc0 SYSC_connect+0x1b6/0x310 ? SYSC_bind+0x280/0x280 ? __do_page_fault+0x5d1/0xca0 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 SyS_connect+0x29/0x30 ? SyS_accept+0x40/0x40 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7ffb3e376259 RSP: 002b:00007ffeda4f6508 EFLAGS: 00000202 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020e77012 RCX: 00007ffb3e376259 RDX: 000000000000002e RSI: 0000000020e77000 RDI: 0000000000000004 RBP: 00007ffeda4f6540 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffeda4f6660 R14: 0000000000000000 R15: 0000000000000000 Code: 80 3d b0 ff 06 02 00 0f 84 07 02 00 00 e8 13 d6 db fc 49 8d bc 24 28 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 f a 48 c1 ea 03 <80> 3c 02 00 0f 85 ed 02 00 00 4d 8b a4 24 28 02 00 00 e8 13 16 Fixes: 80d84ef3ff1dd ("l2tp: prevent l2tp_tunnel_delete racing with userspace close") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26l2tp: don't use inet_shutdown on ppp session destroyJames Chapman1-10/+0
Previously, if a ppp session was closed, we called inet_shutdown to mark the socket as unconnected such that userspace would get errors and then close the socket. This could race with userspace closing the socket. Instead, leave userspace to close the socket in its own time (our session will be detached anyway). BUG: KASAN: use-after-free in inet_shutdown+0x5d/0x1c0 Read of size 4 at addr ffff880010ea3ac0 by task syzbot_347bd5ac/8296 CPU: 3 PID: 8296 Comm: syzbot_347bd5ac Not tainted 4.16.0-rc1+ #91 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 Call Trace: dump_stack+0x101/0x157 ? inet_shutdown+0x5d/0x1c0 print_address_description+0x78/0x260 ? inet_shutdown+0x5d/0x1c0 kasan_report+0x240/0x360 __asan_load4+0x78/0x80 inet_shutdown+0x5d/0x1c0 ? pppol2tp_show+0x80/0x80 pppol2tp_session_close+0x68/0xb0 l2tp_tunnel_closeall+0x199/0x210 ? udp_v6_flush_pending_frames+0x90/0x90 l2tp_udp_encap_destroy+0x6b/0xc0 ? l2tp_tunnel_del_work+0x2e0/0x2e0 udpv6_destroy_sock+0x8c/0x90 sk_common_release+0x47/0x190 udp_lib_close+0x15/0x20 inet_release+0x85/0xd0 inet6_release+0x43/0x60 sock_release+0x53/0x100 ? sock_alloc_file+0x260/0x260 sock_close+0x1b/0x20 __fput+0x19f/0x380 ____fput+0x1a/0x20 task_work_run+0xd2/0x110 exit_to_usermode_loop+0x18d/0x190 do_syscall_64+0x389/0x3b0 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x7fe240a45259 RSP: 002b:00007fe241132df8 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fe240a45259 RDX: 00007fe240a45259 RSI: 0000000000000000 RDI: 00000000000000a5 RBP: 00007fe241132e20 R08: 00007fe241133700 R09: 0000000000000000 R10: 00007fe241133700 R11: 0000000000000297 R12: 0000000000000000 R13: 00007ffc49aff84f R14: 0000000000000000 R15: 00007fe241141040 Allocated by task 8331: save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0x144/0x3e0 sock_alloc_inode+0x22/0x130 alloc_inode+0x3d/0xf0 new_inode_pseudo+0x1c/0x90 sock_alloc+0x30/0x110 __sock_create+0xaa/0x4c0 SyS_socket+0xbe/0x130 do_syscall_64+0x128/0x3b0 entry_SYSCALL_64_after_hwframe+0x26/0x9b Freed by task 8314: save_stack+0x43/0xd0 __kasan_slab_free+0x11a/0x170 kasan_slab_free+0xe/0x10 kmem_cache_free+0x88/0x2b0 sock_destroy_inode+0x49/0x50 destroy_inode+0x77/0xb0 evict+0x285/0x340 iput+0x429/0x530 dentry_unlink_inode+0x28c/0x2c0 __dentry_kill+0x1e3/0x2f0 dput.part.21+0x500/0x560 dput+0x24/0x30 __fput+0x2aa/0x380 ____fput+0x1a/0x20 task_work_run+0xd2/0x110 exit_to_usermode_loop+0x18d/0x190 do_syscall_64+0x389/0x3b0 entry_SYSCALL_64_after_hwframe+0x26/0x9b Fixes: fd558d186df2c ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26l2tp: don't use inet_shutdown on tunnel destroyJames Chapman1-9/+2
Previously, if a tunnel was closed, we called inet_shutdown to mark the socket as unconnected such that userspace would get errors and then close the socket. This could race with userspace closing the socket. Instead, leave userspace to close the socket in its own time (our tunnel will be detached anyway). BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0 IP: __lock_acquire+0x263/0x1630 PGD 0 P4D 0 Oops: 0000 [#1] SMP KASAN Modules linked in: CPU: 2 PID: 42 Comm: kworker/u8:2 Not tainted 4.15.0-rc7+ #129 Workqueue: l2tp l2tp_tunnel_del_work RIP: 0010:__lock_acquire+0x263/0x1630 RSP: 0018:ffff88001a37fc70 EFLAGS: 00010002 RAX: 0000000000000001 RBX: 0000000000000088 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88001a37fd18 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000076fd R12: 00000000000000a0 R13: ffff88001a3722c0 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001ad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a0 CR3: 000000001730b000 CR4: 00000000000006e0 Call Trace: ? __lock_acquire+0xc77/0x1630 ? console_trylock+0x11/0xa0 lock_acquire+0x117/0x230 ? lock_sock_nested+0x3a/0xa0 _raw_spin_lock_bh+0x3a/0x50 ? lock_sock_nested+0x3a/0xa0 lock_sock_nested+0x3a/0xa0 inet_shutdown+0x33/0xf0 l2tp_tunnel_del_work+0x60/0xef process_one_work+0x1ea/0x5f0 ? process_one_work+0x162/0x5f0 worker_thread+0x48/0x3e0 ? trace_hardirqs_on+0xd/0x10 kthread+0x108/0x140 ? process_one_work+0x5f0/0x5f0 ? kthread_stop+0x2a0/0x2a0 ret_from_fork+0x24/0x30 Code: 00 41 81 ff ff 1f 00 00 0f 87 7a 13 00 00 45 85 f6 49 8b 85 68 08 00 00 0f 84 ae 03 00 00 c7 44 24 18 00 00 00 00 e9 f0 00 00 00 <49> 81 3c 24 80 93 3f 83 b8 00 00 00 00 44 0f 44 c0 83 fe 01 0f RIP: __lock_acquire+0x263/0x1630 RSP: ffff88001a37fc70 CR2: 00000000000000a0 Fixes: 309795f4bec2d ("l2tp: Add netlink control API for L2TP") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>