kernel/linux.git/net, branch v3.2.95

pkt_sched: Fix warning false positives.

2017-11-11T13:34:44+00:00

commit f54ba7798848ce1385a71b36a2c997422c82220a upstream. GCC refuses to recognize that all error control flows do in fact set err to something. Add an explicit initialization to shut it up. net/sched/sch_drr.c: In function ‘drr_enqueue’: net/sched/sch_drr.c:359:11: warning: ‘err’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/sched/sch_qfq.c: In function ‘qfq_enqueue’: net/sched/sch_qfq.c:885:11: warning: ‘err’ may be used uninitialized in this function [-Wmaybe-uninitialized] Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

netfilter: xt_socket: fix compilation warnings with gcc 4.7

2017-11-11T13:34:44+00:00

commit 6703aa74ad1ba2e598bb49a37f7518da1195bacb upstream. This patch fixes compilation warnings in xt_socket with gcc-4.7. In file included from net/netfilter/xt_socket.c:22:0: net/netfilter/xt_socket.c: In function ‘socket_mt6_v1’: include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘sport’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:265:16: note: ‘sport’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘dport’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:265:9: note: ‘dport’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘saddr’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:264:27: note: ‘saddr’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘daddr’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:264:19: note: ‘daddr’ was declared here In file included from net/netfilter/xt_socket.c:22:0: net/netfilter/xt_socket.c: In function ‘socket_match.isra.4’: include/net/netfilter/nf_tproxy_core.h:75:2: warning: ‘protocol’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:113:5: note: ‘protocol’ was declared here In file included from include/net/tcp.h:37:0, from net/netfilter/xt_socket.c:17: include/net/inet_hashtables.h:356:45: warning: ‘sport’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:112:16: note: ‘sport’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:106:23: warning: ‘dport’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:112:9: note: ‘dport’ was declared here In file included from include/net/tcp.h:37:0, from net/netfilter/xt_socket.c:17: include/net/inet_hashtables.h:356:15: warning: ‘saddr’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:111:16: note: ‘saddr’ was declared here In file included from include/net/tcp.h:37:0, from net/netfilter/xt_socket.c:17: include/net/inet_hashtables.h:356:15: warning: ‘daddr’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:111:9: note: ‘daddr’ was declared here In file included from net/netfilter/xt_socket.c:22:0: net/netfilter/xt_socket.c: In function ‘socket_mt6_v1’: include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘sport’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:268:16: note: ‘sport’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘dport’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:268:9: note: ‘dport’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘saddr’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:267:27: note: ‘saddr’ was declared here In file included from net/netfilter/xt_socket.c:22:0: include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘daddr’ may be used uninitialized in this function [-Wmaybe-uninitialized] net/netfilter/xt_socket.c:267:19: note: ‘daddr’ was declared here Signed-off-by: Pablo Neira Ayuso [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

dccp: Fix compile warning in probe code.

2017-11-11T13:34:42+00:00

commit d984e6197ecd2babc1537f42dc1e676133005cda upstream. Commit 1386be55e32a3c5d8ef4a2b243c530a7b664c02c ("dccp: fix auto-loading of dccp(_probe)") fixed a bug but created a new compiler warning: net/dccp/probe.c: In function ‘dccpprobe_init’: net/dccp/probe.c:166:2: warning: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Wparentheses] try_then_request_module() is built for situations where the "existence" test is some lookup function that returns a non-NULL object on success, and with a reference count of some kind held. Here we're looking for a success return of zero from the jprobe registry. Instead of fighting the way try_then_request_module() works, simply open code what we want to happen in a local helper function. Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

packet: in packet_do_bind, test fanout with bind_lock held

2017-11-11T13:34:39+00:00

commit 4971613c1639d8e5f102c4e797c3bf8f83a5a69e upstream. Once a socket has po->fanout set, it remains a member of the group until it is destroyed. The prot_hook must be constant and identical across sockets in the group. If fanout_add races with packet_do_bind between the test of po->fanout and taking the lock, the bind call may make type or dev inconsistent with that of the fanout group. Hold po->bind_lock when testing po->fanout to avoid this race. I had to introduce artificial delay (local_bh_enable) to actually observe the race. Fixes: dc99f600698d ("packet: Add fanout support.") Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

packet: hold bind lock when rebinding to fanout hook

2017-11-11T13:34:39+00:00

commit 008ba2a13f2d04c947adc536d19debb8fe66f110 upstream. Packet socket bind operations must hold the po->bind_lock. This keeps po->running consistent with whether the socket is actually on a ptype list to receive packets. fanout_add unbinds a socket and its packet_rcv/tpacket_rcv call, then binds the fanout object to receive through packet_rcv_fanout. Make it hold the po->bind_lock when testing po->running and rebinding. Else, it can race with other rebind operations, such as that in packet_set_ring from packet_rcv to tpacket_rcv. Concurrent updates can result in a socket being added to a fanout group twice, causing use-after-free KASAN bug reports, among others. Reported independently by both trinity and syzkaller. Verified that the syzkaller reproducer passes after this patch. Fixes: dc99f600698d ("packet: Add fanout support.") Reported-by: nixioaming Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller [bwh: Backported to 3.2: use atomic_read() not refcount_read()] Signed-off-by: Ben Hutchings

packet: race condition in packet_bind

2017-11-11T13:34:39+00:00

commit 30f7ea1c2b5f5fb7462c5ae44fe2e40cb2d6a474 upstream. There is a race conditions between packet_notifier and packet_bind{_spkt}. It happens if packet_notifier(NETDEV_UNREGISTER) executes between the time packet_bind{_spkt} takes a reference on the new netdevice and the time packet_do_bind sets po->ifindex. In this case the notification can be missed. If this happens during a dev_change_net_namespace this can result in the netdevice to be moved to the new namespace while the packet_sock in the old namespace still holds a reference on it. When the netdevice is later deleted in the new namespace the deletion hangs since the packet_sock is not found in the new namespace' &net->packet.sklist. It can be reproduced with the script below. This patch makes packet_do_bind check again for the presence of the netdevice in the packet_sock's namespace after the synchronize_net in unregister_prot_hook. More in general it also uses the rcu lock for the duration of the bind to stop dev_change_net_namespace/rollback_registered_many from going past the synchronize_net following unlist_netdevice, so that no NETDEV_UNREGISTER notifications can happen on the new netdevice while the bind is executing. In order to do this some code from packet_bind{_spkt} is consolidated into packet_do_dev. import socket, os, time, sys proto=7 realDev='em1' vlanId=400 if len(sys.argv) > 1: vlanId=int(sys.argv[1]) dev='vlan%d' % vlanId os.system('taskset -p 0x10 %d' % os.getpid()) s = socket.socket(socket.PF_PACKET, socket.SOCK_RAW, proto) os.system('ip link add link %s name %s type vlan id %d' % (realDev, dev, vlanId)) os.system('ip netns add dummy') pid=os.fork() if pid == 0: # dev should be moved while packet_do_bind is in synchronize net os.system('taskset -p 0x20000 %d' % os.getpid()) os.system('ip link set %s netns dummy' % dev) os.system('ip netns exec dummy ip link del %s' % dev) s.close() sys.exit(0) time.sleep(.004) try: s.bind(('%s' % dev, proto+1)) except: print 'Could not bind socket' s.close() os.system('ip netns del dummy') sys.exit(0) os.waitpid(pid, 0) s.close() os.system('ip netns del dummy') sys.exit(0) Signed-off-by: Francesco Ruggeri Signed-off-by: David S. Miller [bwh: Backported to 3.2: - Add the 'dev_curr' variable - Drop the packet_cached_dev changes - Adjust context] Signed-off-by: Ben Hutchings

mac80211: accept key reinstall without changing anything

2017-11-11T13:34:38+00:00

commit fdf7cb4185b60c68e1a75e61691c4afdc15dea0e upstream. When a key is reinstalled we can reset the replay counters etc. which can lead to nonce reuse and/or replay detection being impossible, breaking security properties, as described in the "KRACK attacks". In particular, CVE-2017-13080 applies to GTK rekeying that happened in firmware while the host is in D3, with the second part of the attack being done after the host wakes up. In this case, the wpa_supplicant mitigation isn't sufficient since wpa_supplicant doesn't know the GTK material. In case this happens, simply silently accept the new key coming from userspace but don't take any action on it since it's the same key; this keeps the PN replay counters intact. Signed-off-by: Johannes Berg [bwh: Backported to 3.2: - Use __ieee80211_key_free() instead of ieee80211_key_free_unused() - Adjust context] Signed-off-by: Ben Hutchings

sch_tbf: fix two null pointer dereferences on init failure

2017-11-11T13:34:37+00:00

commit c2d6511e6a4f1f3673d711569c00c3849549e9b0 upstream. sch_tbf calls qdisc_watchdog_cancel() in both its ->reset and ->destroy callbacks but it may fail before the timer is initialized due to missing options (either not supplied by user-space or set as a default qdisc), also q->qdisc is used by ->reset and ->destroy so we need it initialized. Reproduce: $ sysctl net.core.default_qdisc=tbf $ ip l set ethX up Crash log: [ 959.160172] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 959.160323] IP: qdisc_reset+0xa/0x5c [ 959.160400] PGD 59cdb067 [ 959.160401] P4D 59cdb067 [ 959.160466] PUD 59ccb067 [ 959.160532] PMD 0 [ 959.160597] [ 959.160706] Oops: 0000 [#1] SMP [ 959.160778] Modules linked in: sch_tbf sch_sfb sch_prio sch_netem [ 959.160891] CPU: 2 PID: 1562 Comm: ip Not tainted 4.13.0-rc6+ #62 [ 959.160998] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 959.161157] task: ffff880059c9a700 task.stack: ffff8800376d0000 [ 959.161263] RIP: 0010:qdisc_reset+0xa/0x5c [ 959.161347] RSP: 0018:ffff8800376d3610 EFLAGS: 00010286 [ 959.161531] RAX: ffffffffa001b1dd RBX: ffff8800373a2800 RCX: 0000000000000000 [ 959.161733] RDX: ffffffff8215f160 RSI: ffffffff8215f160 RDI: 0000000000000000 [ 959.161939] RBP: ffff8800376d3618 R08: 00000000014080c0 R09: 00000000ffffffff [ 959.162141] R10: ffff8800376d3578 R11: 0000000000000020 R12: ffffffffa001d2c0 [ 959.162343] R13: ffff880037538000 R14: 00000000ffffffff R15: 0000000000000001 [ 959.162546] FS: 00007fcc5126b740(0000) GS:ffff88005d900000(0000) knlGS:0000000000000000 [ 959.162844] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 959.163030] CR2: 0000000000000018 CR3: 000000005abc4000 CR4: 00000000000406e0 [ 959.163233] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 959.163436] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 959.163638] Call Trace: [ 959.163788] tbf_reset+0x19/0x64 [sch_tbf] [ 959.163957] qdisc_destroy+0x8b/0xe5 [ 959.164119] qdisc_create_dflt+0x86/0x94 [ 959.164284] ? dev_activate+0x129/0x129 [ 959.164449] attach_one_default_qdisc+0x36/0x63 [ 959.164623] netdev_for_each_tx_queue+0x3d/0x48 [ 959.164795] dev_activate+0x4b/0x129 [ 959.164957] __dev_open+0xe7/0x104 [ 959.165118] __dev_change_flags+0xc6/0x15c [ 959.165287] dev_change_flags+0x25/0x59 [ 959.165451] do_setlink+0x30c/0xb3f [ 959.165613] ? check_chain_key+0xb0/0xfd [ 959.165782] rtnl_newlink+0x3a4/0x729 [ 959.165947] ? rtnl_newlink+0x117/0x729 [ 959.166121] ? ns_capable_common+0xd/0xb1 [ 959.166288] ? ns_capable+0x13/0x15 [ 959.166450] rtnetlink_rcv_msg+0x188/0x197 [ 959.166617] ? rcu_read_unlock+0x3e/0x5f [ 959.166783] ? rtnl_newlink+0x729/0x729 [ 959.166948] netlink_rcv_skb+0x6c/0xce [ 959.167113] rtnetlink_rcv+0x23/0x2a [ 959.167273] netlink_unicast+0x103/0x181 [ 959.167439] netlink_sendmsg+0x326/0x337 [ 959.167607] sock_sendmsg_nosec+0x14/0x3f [ 959.167772] sock_sendmsg+0x29/0x2e [ 959.167932] ___sys_sendmsg+0x209/0x28b [ 959.168098] ? do_raw_spin_unlock+0xcd/0xf8 [ 959.168267] ? _raw_spin_unlock+0x27/0x31 [ 959.168432] ? __handle_mm_fault+0x651/0xdb1 [ 959.168602] ? check_chain_key+0xb0/0xfd [ 959.168773] __sys_sendmsg+0x45/0x63 [ 959.168934] ? __sys_sendmsg+0x45/0x63 [ 959.169100] SyS_sendmsg+0x19/0x1b [ 959.169260] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 959.169432] RIP: 0033:0x7fcc5097e690 [ 959.169592] RSP: 002b:00007ffd0d5c7b48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 959.169887] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007fcc5097e690 [ 959.170089] RDX: 0000000000000000 RSI: 00007ffd0d5c7b90 RDI: 0000000000000003 [ 959.170292] RBP: ffff8800376d3f98 R08: 0000000000000001 R09: 0000000000000003 [ 959.170494] R10: 00007ffd0d5c7910 R11: 0000000000000246 R12: 0000000000000006 [ 959.170697] R13: 000000000066f1a0 R14: 00007ffd0d5cfc40 R15: 0000000000000000 [ 959.170900] ? trace_hardirqs_off_caller+0xa7/0xcf [ 959.171076] Code: 00 41 c7 84 24 14 01 00 00 00 00 00 00 41 c7 84 24 98 00 00 00 00 00 00 00 41 5c 41 5d 41 5e 5d c3 66 66 66 66 90 55 48 89 e5 53 <48> 8b 47 18 48 89 fb 48 8b 40 48 48 85 c0 74 02 ff d0 48 8b bb [ 959.171637] RIP: qdisc_reset+0xa/0x5c RSP: ffff8800376d3610 [ 959.171821] CR2: 0000000000000018 Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

sch_netem: avoid null pointer deref on init failure

2017-11-11T13:34:37+00:00

commit 634576a1844dba15bc5e6fc61d72f37e13a21615 upstream. netem can fail in ->init due to missing options (either not supplied by user-space or used as a default qdisc) causing a timer->base null pointer deref in its ->destroy() and ->reset() callbacks. Reproduce: $ sysctl net.core.default_qdisc=netem $ ip l set ethX up Crash log: [ 1814.846943] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1814.847181] IP: hrtimer_active+0x17/0x8a [ 1814.847270] PGD 59c34067 [ 1814.847271] P4D 59c34067 [ 1814.847337] PUD 37374067 [ 1814.847403] PMD 0 [ 1814.847468] [ 1814.847582] Oops: 0000 [#1] SMP [ 1814.847655] Modules linked in: sch_netem(O) sch_fq_codel(O) [ 1814.847761] CPU: 3 PID: 1573 Comm: ip Tainted: G O 4.13.0-rc6+ #62 [ 1814.847884] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 1814.848043] task: ffff88003723a700 task.stack: ffff88005adc8000 [ 1814.848235] RIP: 0010:hrtimer_active+0x17/0x8a [ 1814.848407] RSP: 0018:ffff88005adcb590 EFLAGS: 00010246 [ 1814.848590] RAX: 0000000000000000 RBX: ffff880058e359d8 RCX: 0000000000000000 [ 1814.848793] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880058e359d8 [ 1814.848998] RBP: ffff88005adcb5b0 R08: 00000000014080c0 R09: 00000000ffffffff [ 1814.849204] R10: ffff88005adcb660 R11: 0000000000000020 R12: 0000000000000000 [ 1814.849410] R13: ffff880058e359d8 R14: 00000000ffffffff R15: 0000000000000001 [ 1814.849616] FS: 00007f733bbca740(0000) GS:ffff88005d980000(0000) knlGS:0000000000000000 [ 1814.849919] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1814.850107] CR2: 0000000000000000 CR3: 0000000059f0d000 CR4: 00000000000406e0 [ 1814.850313] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1814.850518] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1814.850723] Call Trace: [ 1814.850875] hrtimer_try_to_cancel+0x1a/0x93 [ 1814.851047] hrtimer_cancel+0x15/0x20 [ 1814.851211] qdisc_watchdog_cancel+0x12/0x14 [ 1814.851383] netem_reset+0xe6/0xed [sch_netem] [ 1814.851561] qdisc_destroy+0x8b/0xe5 [ 1814.851723] qdisc_create_dflt+0x86/0x94 [ 1814.851890] ? dev_activate+0x129/0x129 [ 1814.852057] attach_one_default_qdisc+0x36/0x63 [ 1814.852232] netdev_for_each_tx_queue+0x3d/0x48 [ 1814.852406] dev_activate+0x4b/0x129 [ 1814.852569] __dev_open+0xe7/0x104 [ 1814.852730] __dev_change_flags+0xc6/0x15c [ 1814.852899] dev_change_flags+0x25/0x59 [ 1814.853064] do_setlink+0x30c/0xb3f [ 1814.853228] ? check_chain_key+0xb0/0xfd [ 1814.853396] ? check_chain_key+0xb0/0xfd [ 1814.853565] rtnl_newlink+0x3a4/0x729 [ 1814.853728] ? rtnl_newlink+0x117/0x729 [ 1814.853905] ? ns_capable_common+0xd/0xb1 [ 1814.854072] ? ns_capable+0x13/0x15 [ 1814.854234] rtnetlink_rcv_msg+0x188/0x197 [ 1814.854404] ? rcu_read_unlock+0x3e/0x5f [ 1814.854572] ? rtnl_newlink+0x729/0x729 [ 1814.854737] netlink_rcv_skb+0x6c/0xce [ 1814.854902] rtnetlink_rcv+0x23/0x2a [ 1814.855064] netlink_unicast+0x103/0x181 [ 1814.855230] netlink_sendmsg+0x326/0x337 [ 1814.855398] sock_sendmsg_nosec+0x14/0x3f [ 1814.855584] sock_sendmsg+0x29/0x2e [ 1814.855747] ___sys_sendmsg+0x209/0x28b [ 1814.855912] ? do_raw_spin_unlock+0xcd/0xf8 [ 1814.856082] ? _raw_spin_unlock+0x27/0x31 [ 1814.856251] ? __handle_mm_fault+0x651/0xdb1 [ 1814.856421] ? check_chain_key+0xb0/0xfd [ 1814.856592] __sys_sendmsg+0x45/0x63 [ 1814.856755] ? __sys_sendmsg+0x45/0x63 [ 1814.856923] SyS_sendmsg+0x19/0x1b [ 1814.857083] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 1814.857256] RIP: 0033:0x7f733b2dd690 [ 1814.857419] RSP: 002b:00007ffe1d3387d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1814.858238] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007f733b2dd690 [ 1814.858445] RDX: 0000000000000000 RSI: 00007ffe1d338820 RDI: 0000000000000003 [ 1814.858651] RBP: ffff88005adcbf98 R08: 0000000000000001 R09: 0000000000000003 [ 1814.858856] R10: 00007ffe1d3385a0 R11: 0000000000000246 R12: 0000000000000002 [ 1814.859060] R13: 000000000066f1a0 R14: 00007ffe1d3408d0 R15: 0000000000000000 [ 1814.859267] ? trace_hardirqs_off_caller+0xa7/0xcf [ 1814.859446] Code: 10 55 48 89 c7 48 89 e5 e8 45 a1 fb ff 31 c0 5d c3 31 c0 c3 66 66 66 66 90 55 48 89 e5 41 56 41 55 41 54 53 49 89 fd 49 8b 45 30 <4c> 8b 20 41 8b 5c 24 38 31 c9 31 d2 48 c7 c7 50 8e 1d 82 41 89 [ 1814.860022] RIP: hrtimer_active+0x17/0x8a RSP: ffff88005adcb590 [ 1814.860214] CR2: 0000000000000000 Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

sch_cbq: fix null pointer dereferences on init failure

2017-11-11T13:34:37+00:00

commit 3501d059921246ff617b43e86250a719c140bd97 upstream. CBQ can fail on ->init by wrong nl attributes or simply for missing any, f.e. if it's set as a default qdisc then TCA_OPTIONS (opt) will be NULL when it is activated. The first thing init does is parse opt but it will dereference a null pointer if used as a default qdisc, also since init failure at default qdisc invokes ->reset() which cancels all timers then we'll also dereference two more null pointers (timer->base) as they were never initialized. To reproduce: $ sysctl net.core.default_qdisc=cbq $ ip l set ethX up Crash log of the first null ptr deref: [44727.907454] BUG: unable to handle kernel NULL pointer dereference at (null) [44727.907600] IP: cbq_init+0x27/0x205 [44727.907676] PGD 59ff4067 [44727.907677] P4D 59ff4067 [44727.907742] PUD 59c70067 [44727.907807] PMD 0 [44727.907873] [44727.907982] Oops: 0000 [#1] SMP [44727.908054] Modules linked in: [44727.908126] CPU: 1 PID: 21312 Comm: ip Not tainted 4.13.0-rc6+ #60 [44727.908235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [44727.908477] task: ffff88005ad42700 task.stack: ffff880037214000 [44727.908672] RIP: 0010:cbq_init+0x27/0x205 [44727.908838] RSP: 0018:ffff8800372175f0 EFLAGS: 00010286 [44727.909018] RAX: ffffffff816c3852 RBX: ffff880058c53800 RCX: 0000000000000000 [44727.909222] RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffff8800372175f8 [44727.909427] RBP: ffff880037217650 R08: ffffffff81b0f380 R09: 0000000000000000 [44727.909631] R10: ffff880037217660 R11: 0000000000000020 R12: ffffffff822a44c0 [44727.909835] R13: ffff880058b92000 R14: 00000000ffffffff R15: 0000000000000001 [44727.910040] FS: 00007ff8bc583740(0000) GS:ffff88005d880000(0000) knlGS:0000000000000000 [44727.910339] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [44727.910525] CR2: 0000000000000000 CR3: 00000000371e5000 CR4: 00000000000406e0 [44727.910731] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [44727.910936] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [44727.911141] Call Trace: [44727.911291] ? lockdep_init_map+0xb6/0x1ba [44727.911461] ? qdisc_alloc+0x14e/0x187 [44727.911626] qdisc_create_dflt+0x7a/0x94 [44727.911794] ? dev_activate+0x129/0x129 [44727.911959] attach_one_default_qdisc+0x36/0x63 [44727.912132] netdev_for_each_tx_queue+0x3d/0x48 [44727.912305] dev_activate+0x4b/0x129 [44727.912468] __dev_open+0xe7/0x104 [44727.912631] __dev_change_flags+0xc6/0x15c [44727.912799] dev_change_flags+0x25/0x59 [44727.912966] do_setlink+0x30c/0xb3f [44727.913129] ? check_chain_key+0xb0/0xfd [44727.913294] ? check_chain_key+0xb0/0xfd [44727.913463] rtnl_newlink+0x3a4/0x729 [44727.913626] ? rtnl_newlink+0x117/0x729 [44727.913801] ? ns_capable_common+0xd/0xb1 [44727.913968] ? ns_capable+0x13/0x15 [44727.914131] rtnetlink_rcv_msg+0x188/0x197 [44727.914300] ? rcu_read_unlock+0x3e/0x5f [44727.914465] ? rtnl_newlink+0x729/0x729 [44727.914630] netlink_rcv_skb+0x6c/0xce [44727.914796] rtnetlink_rcv+0x23/0x2a [44727.914956] netlink_unicast+0x103/0x181 [44727.915122] netlink_sendmsg+0x326/0x337 [44727.915291] sock_sendmsg_nosec+0x14/0x3f [44727.915459] sock_sendmsg+0x29/0x2e [44727.915619] ___sys_sendmsg+0x209/0x28b [44727.915784] ? do_raw_spin_unlock+0xcd/0xf8 [44727.915954] ? _raw_spin_unlock+0x27/0x31 [44727.916121] ? __handle_mm_fault+0x651/0xdb1 [44727.916290] ? check_chain_key+0xb0/0xfd [44727.916461] __sys_sendmsg+0x45/0x63 [44727.916626] ? __sys_sendmsg+0x45/0x63 [44727.916792] SyS_sendmsg+0x19/0x1b [44727.916950] entry_SYSCALL_64_fastpath+0x23/0xc2 [44727.917125] RIP: 0033:0x7ff8bbc96690 [44727.917286] RSP: 002b:00007ffc360991e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [44727.917579] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007ff8bbc96690 [44727.917783] RDX: 0000000000000000 RSI: 00007ffc36099230 RDI: 0000000000000003 [44727.917987] RBP: ffff880037217f98 R08: 0000000000000001 R09: 0000000000000003 [44727.918190] R10: 00007ffc36098fb0 R11: 0000000000000246 R12: 0000000000000006 [44727.918393] R13: 000000000066f1a0 R14: 00007ffc360a12e0 R15: 0000000000000000 [44727.918597] ? trace_hardirqs_off_caller+0xa7/0xcf [44727.918774] Code: 41 5f 5d c3 66 66 66 66 90 55 48 8d 56 04 45 31 c9 49 c7 c0 80 f3 b0 81 48 89 e5 41 55 41 54 53 48 89 fb 48 8d 7d a8 48 83 ec 48 <0f> b7 0e be 07 00 00 00 83 e9 04 e8 e6 f7 d8 ff 85 c0 0f 88 bb [44727.919332] RIP: cbq_init+0x27/0x205 RSP: ffff8800372175f0 [44727.919516] CR2: 0000000000000000 Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller [bwh: Backported to 3.2: - Keep using HRTIMER_MODE_ABS - Adjust context] Signed-off-by: Ben Hutchings