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2017-08-26packet: fix tp_reserve race in packet_set_ringWillem de Bruijn
commit c27927e372f0785f3303e8fad94b85945e2c97b7 upstream. Updates to tp_reserve can race with reads of the field in packet_set_ring. Avoid this by holding the socket lock during updates in setsockopt PACKET_RESERVE. This bug was discovered by syzkaller. Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-08-26ipv6: avoid overflow of offset in ip6_find_1stfragoptSabrina Dubroca
commit 6399f1fae4ec29fab5ec76070435555e256ca3a6 upstream. In some cases, offset can overflow and can cause an infinite loop in ip6_find_1stfragopt(). Make it unsigned int to prevent the overflow, and cap it at IPV6_MAXPLEN, since packets larger than that should be invalid. This problem has been here since before the beginning of git history. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-08-26tcp: fix wraparound issue in tcp_lpEric Dumazet
commit a9f11f963a546fea9144f6a6d1a307e814a387e7 upstream. Be careful when comparing tcp_time_stamp to some u32 quantity, otherwise result can be surprising. Fixes: 7c106d7e782b ("[TCP]: TCP Low Priority congestion control") Signed-off-by: Eric Dumazet <edumazet@google.com> 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>
2017-08-26ipv6: Need to export ipv6_push_frag_opts for tunneling now.David S. Miller
commit 5b8481fa42ac58484d633b558579e302aead64c1 upstream. Since that change also made the nfrag function not necessary for exports, remove it. Fixes: 89a23c8b528b ("ip6_tunnel: Fix missing tunnel encapsulation limit option") 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>
2017-08-26ip6_tunnel: Fix missing tunnel encapsulation limit optionCraig Gallek
commit 89a23c8b528bd2c89f3981573d6cd7d23840c8a6 upstream. The IPv6 tunneling code tries to insert IPV6_TLV_TNL_ENCAP_LIMIT and IPV6_TLV_PADN options when an encapsulation limit is defined (the default is a limit of 4). An MTU adjustment is done to account for these options as well. However, the options are never present in the generated packets. The issue appears to be a subtlety between IPV6_DSTOPTS and IPV6_RTHDRDSTOPTS defined in RFC 3542. When the IPIP tunnel driver was written, the encap limit options were included as IPV6_RTHDRDSTOPTS in dst0opt of struct ipv6_txoptions. Later, ipv6_push_nfrags_opts was (correctly) updated to require IPV6_RTHDR options when IPV6_RTHDRDSTOPTS are to be used. This caused the options to no longer be included in v6 encapsulated packets. The fix is to use IPV6_DSTOPTS (in dst1opt of struct ipv6_txoptions) instead. IPV6_DSTOPTS do not have the additional IPV6_RTHDR requirement. Fixes: 1df64a8569c7: ("[IPV6]: Add ip6ip6 tunnel driver.") Fixes: 333fad5364d6: ("[IPV6]: Support several new sockopt / ancillary data in Advanced API (RFC3542)") Signed-off-by: Craig Gallek <kraig@google.com> 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>
2017-08-26Bluetooth: Fix user channel for 32bit userspace on 64bit kernelSzymon Janc
commit ab89f0bdd63a3721f7cd3f064f39fc4ac7ca14d4 upstream. Running 32bit userspace on 64bit kernel results in MSG_CMSG_COMPAT being defined as 0x80000000. This results in sendmsg failure if used from 32bit userspace running on 64bit kernel. Fix this by accounting for MSG_CMSG_COMPAT in flags check in hci_sock_sendmsg. Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl> Signed-off-by: Marko Kiiskila <marko@runtime.io> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-08-26netfilter: ctnetlink: make it safer when updating ct->statusLiping Zhang
commit 53b56da83d7899de375a9de153fd7f5397de85e6 upstream. After converting to use rcu for conntrack hash, one CPU may update the ct->status via ctnetlink, while another CPU may process the packets and update the ct->status. So the non-atomic operation "ct->status |= status;" via ctnetlink becomes unsafe, and this may clear the IPS_DYING_BIT bit set by another CPU unexpectedly. For example: CPU0 CPU1 ctnetlink_change_status __nf_conntrack_find_get old = ct->status nf_ct_gc_expired - nf_ct_kill - test_and_set_bit(IPS_DYING_BIT new = old | status; - ct->status = new; <-- oops, _DYING_ is cleared! Now using a series of atomic bit operation to solve the above issue. Also note, user shouldn't set IPS_TEMPLATE, IPS_SEQ_ADJUST directly, so make these two bits be unchangable too. If we set the IPS_TEMPLATE_BIT, ct will be freed by nf_ct_tmpl_free, but actually it is alloced by nf_conntrack_alloc. If we set the IPS_SEQ_ADJUST_BIT, this may cause the NULL pointer deference, as the nfct_seqadj(ct) maybe NULL. Last, add some comments to describe the logic change due to the commit a963d710f367 ("netfilter: ctnetlink: Fix regression in CTA_STATUS processing"), which makes me feel a little confusing. Fixes: 76507f69c44e ("[NETFILTER]: nf_conntrack: use RCU for conntrack hash") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> [bwh: Backported to 3.2: - IPS_UNCHANGEABLE_MASK was not previously defined and ctnetlink_update_status() is not needed - enum ip_conntrack_status only assigns 13 bits - Adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18mac80211: reject ToDS broadcast data framesJohannes Berg
commit 3018e947d7fd536d57e2b550c33e456d921fff8c upstream. AP/AP_VLAN modes don't accept any real 802.11 multicast data frames, but since they do need to accept broadcast management frames the same is currently permitted for data frames. This opens a security problem because such frames would be decrypted with the GTK, and could even contain unicast L3 frames. Since the spec says that ToDS frames must always have the BSSID as the RA (addr1), reject any other data frames. The problem was originally reported in "Predicting, Decrypting, and Abusing WPA2/802.11 Group Keys" at usenix https://www.usenix.org/conference/usenixsecurity16/technical-sessions/presentation/vanhoef and brought to my attention by Jouni. Reported-by: Jouni Malinen <j@w1.fi> Signed-off-by: Johannes Berg <johannes.berg@intel.com> -- Dave, I didn't want to send you a new pull request for a single commit yet again - can you apply this one patch as is? Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: Put the new code in an else-block since the previous if-blocks may or may not return] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18p9_client_readdir() fixAl Viro
commit 71d6ad08379304128e4bdfaf0b4185d54375423e upstream. Don't assume that server is sane and won't return more data than asked for. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18l2tp: don't mask errors in pppol2tp_getsockopt()Guillaume Nault
commit 321a52a39189d5e4af542f7dcdc07bba4545cf5d upstream. pppol2tp_getsockopt() doesn't take into account the error code returned by pppol2tp_tunnel_getsockopt() or pppol2tp_session_getsockopt(). If error occurs there, pppol2tp_getsockopt() continues unconditionally and reports erroneous values. 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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18l2tp: don't mask errors in pppol2tp_setsockopt()Guillaume Nault
commit 364700cf8fd54f54ad08313464105a414e3bccb7 upstream. pppol2tp_setsockopt() unconditionally overwrites the error value returned by pppol2tp_tunnel_setsockopt() or pppol2tp_session_setsockopt(), thus hiding errors from userspace. 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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18l2tp: take reference on sessions being dumpedGuillaume Nault
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>
2017-07-18af_key: Add lock to key dumpYuejie Shi
commit 89e357d83c06b6fac581c3ca7f0ee3ae7e67109e upstream. A dump may come in the middle of another dump, modifying its dump structure members. This race condition will result in NULL pointer dereference in kernel. So add a lock to prevent that race. Fixes: 83321d6b9872 ("[AF_KEY]: Dump SA/SP entries non-atomically") Signed-off-by: Yuejie Shi <syjcnss@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> [bwh: Backported to 3.2: - pfkey_dump() doesn't support filters - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18l2tp: take a reference on sessions used in genetlink handlersGuillaume Nault
commit 2777e2ab5a9cf2b4524486c6db1517a6ded25261 upstream. Callers of l2tp_nl_session_find() need to hold a reference on the returned session since there's no guarantee that it isn't going to disappear from under them. Relying on the fact that no l2tp netlink message may be processed concurrently isn't enough: sessions can be deleted by other means (e.g. by closing the PPPOL2TP socket of a ppp pseudowire). l2tp_nl_cmd_session_delete() is a bit special: it runs a callback function that may require a previous call to session->ref(). In particular, for ppp pseudowires, the callback is l2tp_session_delete(), which then calls pppol2tp_session_close() and dereferences the PPPOL2TP socket. The socket might already be gone at the moment l2tp_session_delete() calls session->ref(), so we need to take a reference during the session lookup. So we need to pass the do_ref variable down to l2tp_session_get() and l2tp_session_get_by_ifname(). Since all callers have to be updated, l2tp_session_find_by_ifname() and l2tp_nl_session_find() are renamed to reflect their new behaviour. 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>
2017-07-18l2tp: fix duplicate session creationGuillaume Nault
commit dbdbc73b44782e22b3b4b6e8b51e7a3d245f3086 upstream. l2tp_session_create() relies on its caller for checking for duplicate sessions. This is racy since a session can be concurrently inserted after the caller's verification. Fix this by letting l2tp_session_create() verify sessions uniqueness upon insertion. Callers need to be adapted to check for l2tp_session_create()'s return code instead of calling l2tp_session_find(). pppol2tp_connect() is a bit special because it has to work on existing sessions (if they're not connected) or to create a new session if none is found. When acting on a preexisting session, a reference must be held or it could go away on us. So we have to use l2tp_session_get() instead of l2tp_session_find() and drop the reference before exiting. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") 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> [bwh: Backported to 3.2: add 'pos' parameter to hlist_for_each_entry{,_rcu}() calls] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18l2tp: ensure session can't get removed during pppol2tp_session_ioctl()Guillaume Nault
commit 57377d63547861919ee634b845c7caa38de4a452 upstream. Holding a reference on session is required before calling pppol2tp_session_ioctl(). The session could get freed while processing the ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket, we also need to take a reference on it in l2tp_session_get(). 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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18l2tp: fix race in l2tp_recv_common()Guillaume Nault
commit 61b9a047729bb230978178bca6729689d0c50ca2 upstream. Taking a reference on sessions in l2tp_recv_common() is racy; this has to be done by the callers. To this end, a new function is required (l2tp_session_get()) to atomically lookup a session and take a reference on it. Callers then have to manually drop this reference. 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> [bwh: Backported to 3.2: - Drop changes to l2tp_ip6.c - Add 'pos' parameter to hlist_for_each_entry{,_rcu}() calls - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18netfilter: nf_nat_snmp: Fix panic when snmp_trap_helper fails to registerGao Feng
commit 75c689dca98851d65ef5a27e5ce26b625b68751c upstream. In the commit 93557f53e1fb ("netfilter: nf_conntrack: nf_conntrack snmp helper"), the snmp_helper is replaced by nf_nat_snmp_hook. So the snmp_helper is never registered. But it still tries to unregister the snmp_helper, it could cause the panic. Now remove the useless snmp_helper and the unregister call in the error handler. Fixes: 93557f53e1fb ("netfilter: nf_conntrack: nf_conntrack snmp helper") Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18sch_dsmark: fix invalid skb_cow() usageEric Dumazet
commit aea92fb2e09e29653b023d4254ac9fbf94221538 upstream. skb_cow(skb, sizeof(ip header)) is not very helpful in this context. First we need to use pskb_may_pull() to make sure the ip header is in skb linear part, then use skb_try_make_writable() to address clones issues. Fixes: 4c30719f4f55 ("[PKT_SCHED] dsmark: handle cloned and non-linear skb's") Signed-off-by: Eric Dumazet <edumazet@google.com> 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>
2017-07-18bpf: try harder on clones when writing into skbDaniel Borkmann
commit 3697649ff29e0f647565eed04b27a7779c646a22 upstream. When we're dealing with clones and the area is not writeable, try harder and get a copy via pskb_expand_head(). Replace also other occurences in tc actions with the new skb_try_make_writable(). Reported-by: Ashhad Sheikh <ashhadsheikh394@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: drop changes to bpf; only tc actions need fixing] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-18net: unix: properly re-increment inflight counter of GC discarded candidatesAndrey Ulanov
commit 7df9c24625b9981779afb8fcdbe2bb4765e61147 upstream. Dmitry has reported that a BUG_ON() condition in unix_notinflight() may be triggered by a simple code that forwards unix socket in an SCM_RIGHTS message. That is caused by incorrect unix socket GC implementation in unix_gc(). The GC first collects list of candidates, then (a) decrements their "children's" inflight counter, (b) checks which inflight counters are now 0, and then (c) increments all inflight counters back. (a) and (c) are done by calling scan_children() with inc_inflight or dec_inflight as the second argument. Commit 6209344f5a37 ("net: unix: fix inflight counting bug in garbage collector") changed scan_children() such that it no longer considers sockets that do not have UNIX_GC_CANDIDATE flag. It also added a block of code that that unsets this flag _before_ invoking scan_children(, dec_iflight, ). This may lead to incorrect inflight counters for some sockets. This change fixes this bug by changing order of operations: UNIX_GC_CANDIDATE is now unset only after all inflight counters are restored to the original state. kernel BUG at net/unix/garbage.c:149! RIP: 0010:[<ffffffff8717ebf4>] [<ffffffff8717ebf4>] unix_notinflight+0x3b4/0x490 net/unix/garbage.c:149 Call Trace: [<ffffffff8716cfbf>] unix_detach_fds.isra.19+0xff/0x170 net/unix/af_unix.c:1487 [<ffffffff8716f6a9>] unix_destruct_scm+0xf9/0x210 net/unix/af_unix.c:1496 [<ffffffff86a90a01>] skb_release_head_state+0x101/0x200 net/core/skbuff.c:655 [<ffffffff86a9808a>] skb_release_all+0x1a/0x60 net/core/skbuff.c:668 [<ffffffff86a980ea>] __kfree_skb+0x1a/0x30 net/core/skbuff.c:684 [<ffffffff86a98284>] kfree_skb+0x184/0x570 net/core/skbuff.c:705 [<ffffffff871789d5>] unix_release_sock+0x5b5/0xbd0 net/unix/af_unix.c:559 [<ffffffff87179039>] unix_release+0x49/0x90 net/unix/af_unix.c:836 [<ffffffff86a694b2>] sock_release+0x92/0x1f0 net/socket.c:570 [<ffffffff86a6962b>] sock_close+0x1b/0x20 net/socket.c:1017 [<ffffffff81a76b8e>] __fput+0x34e/0x910 fs/file_table.c:208 [<ffffffff81a771da>] ____fput+0x1a/0x20 fs/file_table.c:244 [<ffffffff81483ab0>] task_work_run+0x1a0/0x280 kernel/task_work.c:116 [< inline >] exit_task_work include/linux/task_work.h:21 [<ffffffff8141287a>] do_exit+0x183a/0x2640 kernel/exit.c:828 [<ffffffff8141383e>] do_group_exit+0x14e/0x420 kernel/exit.c:931 [<ffffffff814429d3>] get_signal+0x663/0x1880 kernel/signal.c:2307 [<ffffffff81239b45>] do_signal+0xc5/0x2190 arch/x86/kernel/signal.c:807 [<ffffffff8100666a>] exit_to_usermode_loop+0x1ea/0x2d0 arch/x86/entry/common.c:156 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:190 [<ffffffff81009693>] syscall_return_slowpath+0x4d3/0x570 arch/x86/entry/common.c:259 [<ffffffff881478e6>] entry_SYSCALL_64_fastpath+0xc4/0xc6 Link: https://lkml.org/lkml/2017/3/6/252 Signed-off-by: Andrey Ulanov <andreyu@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 6209344 ("net: unix: fix inflight counting bug in garbage collector") 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>
2017-07-18net: ipv6: set route type for anycast routesDavid Ahern
commit 4ee39733fbecf04cf9f346de2d64788c35028079 upstream. Anycast routes have the RTF_ANYCAST flag set, but when dumping routes for userspace the route type is not set to RTN_ANYCAST. Make it so. Fixes: 58c4fb86eabcb ("[IPV6]: Flag RTF_ANYCAST for anycast routes") CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> 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>
2017-07-18udp: avoid ufo handling on IP payload compression packetsAlexey Kodanev
commit 4b3b45edba9222e518a1ec72df841eba3609fe34 upstream. commit c146066ab802 ("ipv4: Don't use ufo handling on later transformed packets") and commit f89c56ce710a ("ipv6: Don't use ufo handling on later transformed packets") added a check that 'rt->dst.header_len' isn't zero in order to skip UFO, but it doesn't include IPcomp in transport mode where it equals zero. Packets, after payload compression, may not require further fragmentation, and if original length exceeds MTU, later compressed packets will be transmitted incorrectly. This can be reproduced with LTP udp_ipsec.sh test on veth device with enabled UFO, MTU is 1500 and UDP payload is 2000: * IPv4 case, offset is wrong + unnecessary fragmentation udp_ipsec.sh -p comp -m transport -s 2000 & tcpdump -ni ltp_ns_veth2 ... IP (tos 0x0, ttl 64, id 45203, offset 0, flags [+], proto Compressed IP (108), length 49) 10.0.0.2 > 10.0.0.1: IPComp(cpi=0x1000) IP (tos 0x0, ttl 64, id 45203, offset 1480, flags [none], proto UDP (17), length 21) 10.0.0.2 > 10.0.0.1: ip-proto-17 * IPv6 case, sending small fragments udp_ipsec.sh -6 -p comp -m transport -s 2000 & tcpdump -ni ltp_ns_veth2 ... IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108) payload length: 37) fd00::2 > fd00::1: IPComp(cpi=0x1000) IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108) payload length: 21) fd00::2 > fd00::1: IPComp(cpi=0x1000) Fix it by checking 'rt->dst.xfrm' pointer to 'xfrm_state' struct, skip UFO if xfrm is set. So the new check will include both cases: IPcomp and IPsec. Fixes: c146066ab802 ("ipv4: Don't use ufo handling on later transformed packets") Fixes: f89c56ce710a ("ipv6: Don't use ufo handling on later transformed packets") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> 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>
2017-07-02rxrpc: Fix several cases where a padded len isn't checked in ticket decodeDavid Howells
commit 5f2f97656ada8d811d3c1bef503ced266fcd53a0 upstream. This fixes CVE-2017-7482. When a kerberos 5 ticket is being decoded so that it can be loaded into an rxrpc-type key, there are several places in which the length of a variable-length field is checked to make sure that it's not going to overrun the available data - but the data is padded to the nearest four-byte boundary and the code doesn't check for this extra. This could lead to the size-remaining variable wrapping and the data pointer going over the end of the buffer. Fix this by making the various variable-length data checks use the padded length. Reported-by: 石磊 <shilei-c@360.cn> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.c.dionne@auristor.com> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05ipv6: fix out of bound writes in __ip6_append_data()Eric Dumazet
commit 232cd35d0804cc241eb887bb8d4d9b3b9881c64a upstream. Andrey Konovalov and idaifish@gmail.com reported crashes caused by one skb shared_info being overwritten from __ip6_append_data() Andrey program lead to following state : copy -4200 datalen 2000 fraglen 2040 maxfraglen 2040 alloclen 2048 transhdrlen 0 offset 0 fraggap 6200 The skb_copy_and_csum_bits(skb_prev, maxfraglen, data + transhdrlen, fraggap, 0); is overwriting skb->head and skb_shared_info Since we apparently detect this rare condition too late, move the code earlier to even avoid allocating skb and risking crashes. Once again, many thanks to Andrey and syzkaller team. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Reported-by: <idaifish@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05ipv6/dccp: do not inherit ipv6_mc_list from parentWANG Cong
commit 83eaddab4378db256d00d295bda6ca997cd13a52 upstream. Like commit 657831ffc38e ("dccp/tcp: do not inherit mc_list from parent") we should clear ipv6_mc_list etc. for IPv6 sockets too. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> 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>
2017-06-05sctp: do not inherit ipv6_{mc|ac|fl}_list from parentEric Dumazet
commit fdcee2cbb8438702ea1b328fb6e0ac5e9a40c7f8 upstream. SCTP needs fixes similar to 83eaddab4378 ("ipv6/dccp: do not inherit ipv6_mc_list from parent"), otherwise bad things can happen. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05ipv6: Check ip6_find_1stfragopt() return value properly.David S. Miller
commit 7dd7eb9513bd02184d45f000ab69d78cb1fa1531 upstream. Do not use unsigned variables to see if it returns a negative error or not. Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options") Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust filenames, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05ipv6: Prevent overrun when parsing v6 header optionsCraig Gallek
commit 2423496af35d94a87156b063ea5cedffc10a70a1 upstream. The KASAN warning repoted below was discovered with a syzkaller program. The reproducer is basically: int s = socket(AF_INET6, SOCK_RAW, NEXTHDR_HOP); send(s, &one_byte_of_data, 1, MSG_MORE); send(s, &more_than_mtu_bytes_data, 2000, 0); The socket() call sets the nexthdr field of the v6 header to NEXTHDR_HOP, the first send call primes the payload with a non zero byte of data, and the second send call triggers the fragmentation path. The fragmentation code tries to parse the header options in order to figure out where to insert the fragment option. Since nexthdr points to an invalid option, the calculation of the size of the network header can made to be much larger than the linear section of the skb and data is read outside of it. This fix makes ip6_find_1stfrag return an error if it detects running out-of-bounds. [ 42.361487] ================================================================== [ 42.364412] BUG: KASAN: slab-out-of-bounds in ip6_fragment+0x11c8/0x3730 [ 42.365471] Read of size 840 at addr ffff88000969e798 by task ip6_fragment-oo/3789 [ 42.366469] [ 42.366696] CPU: 1 PID: 3789 Comm: ip6_fragment-oo Not tainted 4.11.0+ #41 [ 42.367628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014 [ 42.368824] Call Trace: [ 42.369183] dump_stack+0xb3/0x10b [ 42.369664] print_address_description+0x73/0x290 [ 42.370325] kasan_report+0x252/0x370 [ 42.370839] ? ip6_fragment+0x11c8/0x3730 [ 42.371396] check_memory_region+0x13c/0x1a0 [ 42.371978] memcpy+0x23/0x50 [ 42.372395] ip6_fragment+0x11c8/0x3730 [ 42.372920] ? nf_ct_expect_unregister_notifier+0x110/0x110 [ 42.373681] ? ip6_copy_metadata+0x7f0/0x7f0 [ 42.374263] ? ip6_forward+0x2e30/0x2e30 [ 42.374803] ip6_finish_output+0x584/0x990 [ 42.375350] ip6_output+0x1b7/0x690 [ 42.375836] ? ip6_finish_output+0x990/0x990 [ 42.376411] ? ip6_fragment+0x3730/0x3730 [ 42.376968] ip6_local_out+0x95/0x160 [ 42.377471] ip6_send_skb+0xa1/0x330 [ 42.377969] ip6_push_pending_frames+0xb3/0xe0 [ 42.378589] rawv6_sendmsg+0x2051/0x2db0 [ 42.379129] ? rawv6_bind+0x8b0/0x8b0 [ 42.379633] ? _copy_from_user+0x84/0xe0 [ 42.380193] ? debug_check_no_locks_freed+0x290/0x290 [ 42.380878] ? ___sys_sendmsg+0x162/0x930 [ 42.381427] ? rcu_read_lock_sched_held+0xa3/0x120 [ 42.382074] ? sock_has_perm+0x1f6/0x290 [ 42.382614] ? ___sys_sendmsg+0x167/0x930 [ 42.383173] ? lock_downgrade+0x660/0x660 [ 42.383727] inet_sendmsg+0x123/0x500 [ 42.384226] ? inet_sendmsg+0x123/0x500 [ 42.384748] ? inet_recvmsg+0x540/0x540 [ 42.385263] sock_sendmsg+0xca/0x110 [ 42.385758] SYSC_sendto+0x217/0x380 [ 42.386249] ? SYSC_connect+0x310/0x310 [ 42.386783] ? __might_fault+0x110/0x1d0 [ 42.387324] ? lock_downgrade+0x660/0x660 [ 42.387880] ? __fget_light+0xa1/0x1f0 [ 42.388403] ? __fdget+0x18/0x20 [ 42.388851] ? sock_common_setsockopt+0x95/0xd0 [ 42.389472] ? SyS_setsockopt+0x17f/0x260 [ 42.390021] ? entry_SYSCALL_64_fastpath+0x5/0xbe [ 42.390650] SyS_sendto+0x40/0x50 [ 42.391103] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.391731] RIP: 0033:0x7fbbb711e383 [ 42.392217] RSP: 002b:00007ffff4d34f28 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 42.393235] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbbb711e383 [ 42.394195] RDX: 0000000000001000 RSI: 00007ffff4d34f60 RDI: 0000000000000003 [ 42.395145] RBP: 0000000000000046 R08: 00007ffff4d34f40 R09: 0000000000000018 [ 42.396056] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400aad [ 42.396598] R13: 0000000000000066 R14: 00007ffff4d34ee0 R15: 00007fbbb717af00 [ 42.397257] [ 42.397411] Allocated by task 3789: [ 42.397702] save_stack_trace+0x16/0x20 [ 42.398005] save_stack+0x46/0xd0 [ 42.398267] kasan_kmalloc+0xad/0xe0 [ 42.398548] kasan_slab_alloc+0x12/0x20 [ 42.398848] __kmalloc_node_track_caller+0xcb/0x380 [ 42.399224] __kmalloc_reserve.isra.32+0x41/0xe0 [ 42.399654] __alloc_skb+0xf8/0x580 [ 42.400003] sock_wmalloc+0xab/0xf0 [ 42.400346] __ip6_append_data.isra.41+0x2472/0x33d0 [ 42.400813] ip6_append_data+0x1a8/0x2f0 [ 42.401122] rawv6_sendmsg+0x11ee/0x2db0 [ 42.401505] inet_sendmsg+0x123/0x500 [ 42.401860] sock_sendmsg+0xca/0x110 [ 42.402209] ___sys_sendmsg+0x7cb/0x930 [ 42.402582] __sys_sendmsg+0xd9/0x190 [ 42.402941] SyS_sendmsg+0x2d/0x50 [ 42.403273] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.403718] [ 42.403871] Freed by task 1794: [ 42.404146] save_stack_trace+0x16/0x20 [ 42.404515] save_stack+0x46/0xd0 [ 42.404827] kasan_slab_free+0x72/0xc0 [ 42.405167] kfree+0xe8/0x2b0 [ 42.405462] skb_free_head+0x74/0xb0 [ 42.405806] skb_release_data+0x30e/0x3a0 [ 42.406198] skb_release_all+0x4a/0x60 [ 42.406563] consume_skb+0x113/0x2e0 [ 42.406910] skb_free_datagram+0x1a/0xe0 [ 42.407288] netlink_recvmsg+0x60d/0xe40 [ 42.407667] sock_recvmsg+0xd7/0x110 [ 42.408022] ___sys_recvmsg+0x25c/0x580 [ 42.408395] __sys_recvmsg+0xd6/0x190 [ 42.408753] SyS_recvmsg+0x2d/0x50 [ 42.409086] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.409513] [ 42.409665] The buggy address belongs to the object at ffff88000969e780 [ 42.409665] which belongs to the cache kmalloc-512 of size 512 [ 42.410846] The buggy address is located 24 bytes inside of [ 42.410846] 512-byte region [ffff88000969e780, ffff88000969e980) [ 42.411941] The buggy address belongs to the page: [ 42.412405] page:ffffea000025a780 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 42.413298] flags: 0x100000000008100(slab|head) [ 42.413729] raw: 0100000000008100 0000000000000000 0000000000000000 00000001800c000c [ 42.414387] raw: ffffea00002a9500 0000000900000007 ffff88000c401280 0000000000000000 [ 42.415074] page dumped because: kasan: bad access detected [ 42.415604] [ 42.415757] Memory state around the buggy address: [ 42.416222] ffff88000969e880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 42.416904] ffff88000969e900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 42.417591] >ffff88000969e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 42.418273] ^ [ 42.418588] ffff88000969ea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.419273] ffff88000969ea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.419882] ================================================================== Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust filenames, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05dccp/tcp: do not inherit mc_list from parentEric Dumazet
commit 657831ffc38e30092a2d5f03d385d710eb88b09a upstream. syzkaller found a way to trigger double frees from ip_mc_drop_socket() It turns out that leave a copy of parent mc_list at accept() time, which is very bad. Very similar to commit 8b485ce69876 ("tcp: do not inherit fastopen_req from parent") Initial report from Pray3r, completed by Andrey one. Thanks a lot to them ! Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Pray3r <pray3r.z@gmail.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> 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>
2017-06-05ipx: call ipxitf_put() in ioctl error pathDan Carpenter
commit ee0d8d8482345ff97a75a7d747efc309f13b0d80 upstream. We should call ipxitf_put() if the copy_to_user() fails. Reported-by: 李强 <liqiang6-s@360.cn> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05net/packet: fix overflow in check for tp_reserveAndrey Konovalov
commit bcc5364bdcfe131e6379363f089e7b4108d35b70 upstream. When calculating po->tp_hdrlen + po->tp_reserve the result can overflow. Fix by checking that tp_reserve <= INT_MAX on assign. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05net/packet: fix overflow in check for tp_frame_nrAndrey Konovalov
commit 8f8d28e4d6d815a391285e121c3a53a0b6cb9e7b upstream. When calculating rb->frames_per_block * req->tp_block_nr the result can overflow. Add a check that tp_block_size * tp_block_nr <= UINT_MAX. Since frames_per_block <= tp_block_size, the expression would never overflow. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05net/packet: fix overflow in check for priv area sizeAndrey Konovalov
commit 2b6867c2ce76c596676bec7d2d525af525fdc6e2 upstream. Subtracting tp_sizeof_priv from tp_block_size and casting to int to check whether one is less then the other doesn't always work (both of them are unsigned ints). Compare them as is instead. Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as it can overflow inside BLK_PLUS_PRIV otherwise. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05packet: handle too big packets for PACKET_V3Eric Dumazet
commit dc808110bb62b64a448696ecac3938902c92e1ab upstream. af_packet can currently overwrite kernel memory by out of bound accesses, because it assumed a [new] block can always hold one frame. This is not generally the case, even if most existing tools do it right. This patch clamps too long frames as API permits, and issue a one time error on syslog. [ 394.357639] tpacket_rcv: packet too big, clamped from 5042 to 3966. macoff=82 In this example, packet header tp_snaplen was set to 3966, and tp_len was set to 5042 (skb->len) Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harderAndy Whitcroft
commit f843ee6dd019bcece3e74e76ad9df0155655d0df upstream. Kees Cook has pointed out that xfrm_replay_state_esn_len() is subject to wrapping issues. To ensure we are correctly ensuring that the two ESN structures are the same size compare both the overall size as reported by xfrm_replay_state_esn_len() and the internal length are the same. CVE-2017-7184 Signed-off-by: Andy Whitcroft <apw@canonical.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_windowAndy Whitcroft
commit 677e806da4d916052585301785d847c3b3e6186a upstream. When a new xfrm state is created during an XFRM_MSG_NEWSA call we validate the user supplied replay_esn to ensure that the size is valid and to ensure that the replay_window size is within the allocated buffer. However later it is possible to update this replay_esn via a XFRM_MSG_NEWAE call. There we again validate the size of the supplied buffer matches the existing state and if so inject the contents. We do not at this point check that the replay_window is within the allocated memory. This leads to out-of-bounds reads and writes triggered by netlink packets. This leads to memory corruption and the potential for priviledge escalation. We already attempt to validate the incoming replay information in xfrm_new_ae() via xfrm_replay_verify_len(). This confirms that the user is not trying to change the size of the replay state buffer which includes the replay_esn. It however does not check the replay_window remains within that buffer. Add validation of the contained replay_window. CVE-2017-7184 Signed-off-by: Andy Whitcroft <apw@canonical.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-06-05ping: implement proper lockingEric Dumazet
commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream. We got a report of yet another bug in ping http://www.openwall.com/lists/oss-security/2017/03/24/6 ->disconnect() is not called with socket lock held. Fix this by acquiring ping rwlock earlier. Thanks to Daniel, Alexander and Andrey for letting us know this problem. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Daniel Jiang <danieljiang0415@gmail.com> Reported-by: Solar Designer <solar@openwall.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> 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>
2017-06-05net sched actions: decrement module reference count after table flush.Roman Mashak
commit edb9d1bff4bbe19b8ae0e71b1f38732591a9eeb2 upstream. When tc actions are loaded as a module and no actions have been installed, flushing them would result in actions removed from the memory, but modules reference count not being decremented, so that the modules would not be unloaded. Following is example with GACT action: % sudo modprobe act_gact % lsmod Module Size Used by act_gact 16384 0 % % sudo tc actions ls action gact % % sudo tc actions flush action gact % lsmod Module Size Used by act_gact 16384 1 % sudo tc actions flush action gact % lsmod Module Size Used by act_gact 16384 2 % sudo rmmod act_gact rmmod: ERROR: Module act_gact is in use .... After the fix: % lsmod Module Size Used by act_gact 16384 0 % % sudo tc actions add action pass index 1 % sudo tc actions add action pass index 2 % sudo tc actions add action pass index 3 % lsmod Module Size Used by act_gact 16384 3 % % sudo tc actions flush action gact % lsmod Module Size Used by act_gact 16384 0 % % sudo tc actions flush action gact % lsmod Module Size Used by act_gact 16384 0 % sudo rmmod act_gact % lsmod Module Size Used by % Fixes: f97017cdefef ("net-sched: Fix actions flushing") Signed-off-by: Roman Mashak <mrv@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> 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>
2017-06-05net/dccp: fix use after free in tw_timer_handler()Andrey Ryabinin
commit ec7cb62d18d854ea09df8b7194e7e710985f8b9a upstream. DCCP doesn't purge timewait sockets on network namespace shutdown. So, after net namespace destroyed we could still have an active timer which will trigger use after free in tw_timer_handler(): BUG: KASAN: use-after-free in tw_timer_handler+0x4a/0xa0 at addr ffff88010e0d1e10 Read of size 8 by task swapper/1/0 Call Trace: __asan_load8+0x54/0x90 tw_timer_handler+0x4a/0xa0 call_timer_fn+0x127/0x480 expire_timers+0x1db/0x2e0 run_timer_softirq+0x12f/0x2a0 __do_softirq+0x105/0x5b4 irq_exit+0xdd/0xf0 smp_apic_timer_interrupt+0x57/0x70 apic_timer_interrupt+0x90/0xa0 Object at ffff88010e0d1bc0, in cache net_namespace size: 6848 Allocated: save_stack_trace+0x1b/0x20 kasan_kmalloc+0xee/0x180 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0x134/0x310 copy_net_ns+0x8d/0x280 create_new_namespaces+0x23f/0x340 unshare_nsproxy_namespaces+0x75/0xf0 SyS_unshare+0x299/0x4f0 entry_SYSCALL_64_fastpath+0x18/0xad Freed: save_stack_trace+0x1b/0x20 kasan_slab_free+0xae/0x180 kmem_cache_free+0xb4/0x350 net_drop_ns+0x3f/0x50 cleanup_net+0x3df/0x450 process_one_work+0x419/0xbb0 worker_thread+0x92/0x850 kthread+0x192/0x1e0 ret_from_fork+0x2e/0x40 Add .exit_batch hook to dccp_v4_ops()/dccp_v6_ops() which will purge timewait sockets on net namespace destruction and prevent above issue. Fixes: f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: pass twdr parameter to inet_twsk_purge() Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-04-04l2tp: fix racy SOCK_ZAPPED flag check in l2tp_ip{,6}_bind()Guillaume Nault
commit 32c231164b762dddefa13af5a0101032c70b50ef upstream. Lock socket before checking the SOCK_ZAPPED flag in l2tp_ip6_bind(). Without lock, a concurrent call could modify the socket flags between the sock_flag(sk, SOCK_ZAPPED) test and the lock_sock() call. This way, a socket could be inserted twice in l2tp_ip6_bind_table. Releasing it would then leave a stale pointer there, generating use-after-free errors when walking through the list or modifying adjacent entries. BUG: KASAN: use-after-free in l2tp_ip6_close+0x22e/0x290 at addr ffff8800081b0ed8 Write of size 8 by task syz-executor/10987 CPU: 0 PID: 10987 Comm: syz-executor Not tainted 4.8.0+ #39 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 ffff880031d97838 ffffffff829f835b ffff88001b5a1640 ffff8800081b0ec0 ffff8800081b15a0 ffff8800081b6d20 ffff880031d97860 ffffffff8174d3cc ffff880031d978f0 ffff8800081b0e80 ffff88001b5a1640 ffff880031d978e0 Call Trace: [<ffffffff829f835b>] dump_stack+0xb3/0x118 lib/dump_stack.c:15 [<ffffffff8174d3cc>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:156 [< inline >] print_address_description mm/kasan/report.c:194 [<ffffffff8174d666>] kasan_report_error+0x1f6/0x4d0 mm/kasan/report.c:283 [< inline >] kasan_report mm/kasan/report.c:303 [<ffffffff8174db7e>] __asan_report_store8_noabort+0x3e/0x40 mm/kasan/report.c:329 [< inline >] __write_once_size ./include/linux/compiler.h:249 [< inline >] __hlist_del ./include/linux/list.h:622 [< inline >] hlist_del_init ./include/linux/list.h:637 [<ffffffff8579047e>] l2tp_ip6_close+0x22e/0x290 net/l2tp/l2tp_ip6.c:239 [<ffffffff850b2dfd>] inet_release+0xed/0x1c0 net/ipv4/af_inet.c:415 [<ffffffff851dc5a0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:422 [<ffffffff84c4581d>] sock_release+0x8d/0x1d0 net/socket.c:570 [<ffffffff84c45976>] sock_close+0x16/0x20 net/socket.c:1017 [<ffffffff817a108c>] __fput+0x28c/0x780 fs/file_table.c:208 [<ffffffff817a1605>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff813774f9>] task_work_run+0xf9/0x170 [<ffffffff81324aae>] do_exit+0x85e/0x2a00 [<ffffffff81326dc8>] do_group_exit+0x108/0x330 [<ffffffff81348cf7>] get_signal+0x617/0x17a0 kernel/signal.c:2307 [<ffffffff811b49af>] do_signal+0x7f/0x18f0 [<ffffffff810039bf>] exit_to_usermode_loop+0xbf/0x150 arch/x86/entry/common.c:156 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:190 [<ffffffff81006060>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259 [<ffffffff85e4d726>] entry_SYSCALL_64_fastpath+0xc4/0xc6 Object at ffff8800081b0ec0, in cache L2TP/IPv6 size: 1448 Allocated: PID = 10987 [ 1116.897025] [<ffffffff811ddcb6>] save_stack_trace+0x16/0x20 [ 1116.897025] [<ffffffff8174c736>] save_stack+0x46/0xd0 [ 1116.897025] [<ffffffff8174c9ad>] kasan_kmalloc+0xad/0xe0 [ 1116.897025] [<ffffffff8174cee2>] kasan_slab_alloc+0x12/0x20 [ 1116.897025] [< inline >] slab_post_alloc_hook mm/slab.h:417 [ 1116.897025] [< inline >] slab_alloc_node mm/slub.c:2708 [ 1116.897025] [< inline >] slab_alloc mm/slub.c:2716 [ 1116.897025] [<ffffffff817476a8>] kmem_cache_alloc+0xc8/0x2b0 mm/slub.c:2721 [ 1116.897025] [<ffffffff84c4f6a9>] sk_prot_alloc+0x69/0x2b0 net/core/sock.c:1326 [ 1116.897025] [<ffffffff84c58ac8>] sk_alloc+0x38/0xae0 net/core/sock.c:1388 [ 1116.897025] [<ffffffff851ddf67>] inet6_create+0x2d7/0x1000 net/ipv6/af_inet6.c:182 [ 1116.897025] [<ffffffff84c4af7b>] __sock_create+0x37b/0x640 net/socket.c:1153 [ 1116.897025] [< inline >] sock_create net/socket.c:1193 [ 1116.897025] [< inline >] SYSC_socket net/socket.c:1223 [ 1116.897025] [<ffffffff84c4b46f>] SyS_socket+0xef/0x1b0 net/socket.c:1203 [ 1116.897025] [<ffffffff85e4d685>] entry_SYSCALL_64_fastpath+0x23/0xc6 Freed: PID = 10987 [ 1116.897025] [<ffffffff811ddcb6>] save_stack_trace+0x16/0x20 [ 1116.897025] [<ffffffff8174c736>] save_stack+0x46/0xd0 [ 1116.897025] [<ffffffff8174cf61>] kasan_slab_free+0x71/0xb0 [ 1116.897025] [< inline >] slab_free_hook mm/slub.c:1352 [ 1116.897025] [< inline >] slab_free_freelist_hook mm/slub.c:1374 [ 1116.897025] [< inline >] slab_free mm/slub.c:2951 [ 1116.897025] [<ffffffff81748b28>] kmem_cache_free+0xc8/0x330 mm/slub.c:2973 [ 1116.897025] [< inline >] sk_prot_free net/core/sock.c:1369 [ 1116.897025] [<ffffffff84c541eb>] __sk_destruct+0x32b/0x4f0 net/core/sock.c:1444 [ 1116.897025] [<ffffffff84c5aca4>] sk_destruct+0x44/0x80 net/core/sock.c:1452 [ 1116.897025] [<ffffffff84c5ad33>] __sk_free+0x53/0x220 net/core/sock.c:1460 [ 1116.897025] [<ffffffff84c5af23>] sk_free+0x23/0x30 net/core/sock.c:1471 [ 1116.897025] [<ffffffff84c5cb6c>] sk_common_release+0x28c/0x3e0 ./include/net/sock.h:1589 [ 1116.897025] [<ffffffff8579044e>] l2tp_ip6_close+0x1fe/0x290 net/l2tp/l2tp_ip6.c:243 [ 1116.897025] [<ffffffff850b2dfd>] inet_release+0xed/0x1c0 net/ipv4/af_inet.c:415 [ 1116.897025] [<ffffffff851dc5a0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:422 [ 1116.897025] [<ffffffff84c4581d>] sock_release+0x8d/0x1d0 net/socket.c:570 [ 1116.897025] [<ffffffff84c45976>] sock_close+0x16/0x20 net/socket.c:1017 [ 1116.897025] [<ffffffff817a108c>] __fput+0x28c/0x780 fs/file_table.c:208 [ 1116.897025] [<ffffffff817a1605>] ____fput+0x15/0x20 fs/file_table.c:244 [ 1116.897025] [<ffffffff813774f9>] task_work_run+0xf9/0x170 [ 1116.897025] [<ffffffff81324aae>] do_exit+0x85e/0x2a00 [ 1116.897025] [<ffffffff81326dc8>] do_group_exit+0x108/0x330 [ 1116.897025] [<ffffffff81348cf7>] get_signal+0x617/0x17a0 kernel/signal.c:2307 [ 1116.897025] [<ffffffff811b49af>] do_signal+0x7f/0x18f0 [ 1116.897025] [<ffffffff810039bf>] exit_to_usermode_loop+0xbf/0x150 arch/x86/entry/common.c:156 [ 1116.897025] [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:190 [ 1116.897025] [<ffffffff81006060>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259 [ 1116.897025] [<ffffffff85e4d726>] entry_SYSCALL_64_fastpath+0xc4/0xc6 Memory state around the buggy address: ffff8800081b0d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8800081b0e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8800081b0e80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8800081b0f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8800081b0f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== The same issue exists with l2tp_ip_bind() and l2tp_ip_bind_table. Fixes: c51ce49735c1 ("l2tp: fix oops in L2TP IP sockets for connect() AF_UNSPEC case") Reported-by: Baozeng Ding <sploving1@gmail.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: drop IPv6 changes] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-04-04ipv4: keep skb->dst around in presence of IP optionsEric Dumazet
Upstream commit 34b2cef20f19c87999fff3da4071e66937db9644 ("ipv4: keep skb->dst around in presence of IP options") incorrectly root caused commit d826eb14ecef ("ipv4: PKTINFO doesnt need dst reference") as bug origin. This patch should fix the issue for 3.2.xx stable kernels, since IPv4 options seem to get more traction these days, after years of oblivion ;) Fixes: f84af32cbca70 ("net: ip_queue_rcv_skb() helper")) Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Anarcheuz Fritz <anarcheuz@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16sctp: deny peeloff operation on asocs with threads sleeping on itMarcelo Ricardo Leitner
commit dfcb9f4f99f1e9a49e43398a7bfbf56927544af1 upstream. commit 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf") attempted to avoid a BUG_ON call when the association being used for a sendmsg() is blocked waiting for more sndbuf and another thread did a peeloff operation on such asoc, moving it to another socket. As Ben Hutchings noticed, then in such case it would return without locking back the socket and would cause two unlocks in a row. Further analysis also revealed that it could allow a double free if the application managed to peeloff the asoc that is created during the sendmsg call, because then sctp_sendmsg() would try to free the asoc that was created only for that call. This patch takes another approach. It will deny the peeloff operation if there is a thread sleeping on the asoc, so this situation doesn't exist anymore. This avoids the issues described above and also honors the syscalls that are already being handled (it can be multiple sendmsg calls). Joint work with Xin Long. Fixes: 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf") Cc: Alexander Popov <alex.popov@linux.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> 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>
2017-03-16sctp: avoid BUG_ON on sctp_wait_for_sndbufMarcelo Ricardo Leitner
commit 2dcab598484185dea7ec22219c76dcdd59e3cb90 upstream. Alexander Popov reported that an application may trigger a BUG_ON in sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is waiting on it to queue more data and meanwhile another thread peels off the association being used by the first thread. This patch replaces the BUG_ON call with a proper error handling. It will return -EPIPE to the original sendmsg call, similarly to what would have been done if the association wasn't found in the first place. Acked-by: Alexander Popov <alex.popov@linux.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> 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>
2017-03-16igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()Hangbin Liu
commit 9c8bb163ae784be4f79ae504e78c862806087c54 upstream. In function igmpv3/mld_add_delrec() we allocate pmc and put it in idev->mc_tomb, so we should free it when we don't need it in del_delrec(). But I removed kfree(pmc) incorrectly in latest two patches. Now fix it. Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info when ...") Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when ...") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16mld: do not remove mld souce list info when set link downHangbin Liu
commit 1666d49e1d416fcc2cce708242a52fe3317ea8ba upstream. This is an IPv6 version of commit 24803f38a5c0 ("igmp: do not remove igmp souce list..."). In mld_del_delrec(), we will restore back all source filter info instead of flush them. Move mld_clear_delrec() from ipv6_mc_down() to ipv6_mc_destroy_dev() since we should not remove source list info when set link down. Remove igmp6_group_dropped() in ipv6_mc_destroy_dev() since we have called it in ipv6_mc_down(). Also clear all source info after igmp6_group_dropped() instead of in it because ipv6_mc_down() will call igmp6_group_dropped(). Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Timer code moved around in ipv6_mc_down() is different - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16igmp: do not remove igmp souce list info when set link downHangbin Liu
commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a upstream. In commit 24cf3af3fed5 ("igmp: call ip_mc_clear_src..."), we forgot to remove igmpv3_clear_delrec() in ip_mc_down(), which also called ip_mc_clear_src(). This make us clear all IGMPv3 source filter info after NETDEV_DOWN. Move igmpv3_clear_delrec() to ip_mc_destroy_dev() and then no need ip_mc_clear_src() in ip_mc_destroy_dev(). On the other hand, we should restore back instead of free all source filter info in igmpv3_del_delrec(). Or we will not able to restore IGMPv3 source filter info after NETDEV_UP and NETDEV_POST_TYPE_CHANGE. Fixes: 24cf3af3fed5 ("igmp: call ip_mc_clear_src() only when ...") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Use IGMP_Unsolicited_Report_Count instead of sysctl_igmp_qrv - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16tcp: fix 0 divide in __tcp_select_window()Eric Dumazet
[ Upstream commit 06425c308b92eaf60767bc71d359f4cbc7a561f8 ] syszkaller fuzzer was able to trigger a divide by zero, when TCP window scaling is not enabled. SO_RCVBUF can be used not only to increase sk_rcvbuf, also to decrease it below current receive buffers utilization. If mss is negative or 0, just return a zero TCP window. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16ipv6: pointer math error in ip6_tnl_parse_tlv_enc_lim()Dan Carpenter
[ Upstream commit 63117f09c768be05a0bf465911297dc76394f686 ] Casting is a high precedence operation but "off" and "i" are in terms of bytes so we need to have some parenthesis here. Fixes: fbfa743a9d2a ("ipv6: fix ip6_tnl_parse_tlv_enc_lim()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16ipv6: fix ip6_tnl_parse_tlv_enc_lim()Eric Dumazet
[ Upstream commit fbfa743a9d2a0ffa24251764f10afc13eb21e739 ] This function suffers from multiple issues. First one is that pskb_may_pull() may reallocate skb->head, so the 'raw' pointer needs either to be reloaded or not used at all. Second issue is that NEXTHDR_DEST handling does not validate that the options are present in skb->data, so we might read garbage or access non existent memory. With help from Willem de Bruijn. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>