linux-stable.git/drivers/net/ppp, branch linux-3.10.y Linux kernel stable tree ppp: defer netns reference release for ppp channel 2017-02-06T08:04:07+00:00 WANG Cong xiyou.wangcong@gmail.com 2016-07-06T05:12:36+00:00 068b35e923cd27bad171e4031e4963c3c8ee2170 commit 205e1e255c479f3fd77446415706463b282f94e4 upstream Matt reported that we have a NULL pointer dereference in ppp_pernet() from ppp_connect_channel(), i.e. pch->chan_net is NULL. This is due to that a parallel ppp_unregister_channel() could happen while we are in ppp_connect_channel(), during which pch->chan_net set to NULL. Since we need a reference to net per channel, it makes sense to sync the refcnt with the life time of the channel, therefore we should release this reference when we destroy it. Fixes: 1f461dcdd296 ("ppp: take reference on channels netns") Reported-by: Matt Bennett <Matt.Bennett@alliedtelesis.co.nz> Cc: Paul Mackerras <paulus@samba.org> Cc: linux-ppp@vger.kernel.org Cc: Guillaume Nault <g.nault@alphalink.fr> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu> 
commit 205e1e255c479f3fd77446415706463b282f94e4 upstream

Matt reported that we have a NULL pointer dereference
in ppp_pernet() from ppp_connect_channel(),
i.e. pch->chan_net is NULL.

This is due to that a parallel ppp_unregister_channel()
could happen while we are in ppp_connect_channel(), during
which pch->chan_net set to NULL. Since we need a reference
to net per channel, it makes sense to sync the refcnt
with the life time of the channel, therefore we should
release this reference when we destroy it.

Fixes: 1f461dcdd296 ("ppp: take reference on channels netns")
Reported-by: Matt Bennett <Matt.Bennett@alliedtelesis.co.nz>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
ppp: take reference on channels netns 2016-06-07T08:42:49+00:00 Guillaume Nault g.nault@alphalink.fr 2016-03-23T15:38:55+00:00 c57d15c3c4ecee01fb151a717a0f4b280e73ae24 commit 1f461dcdd296eecedaffffc6bae2bfa90bd7eb89 upstream. Let channels hold a reference on their network namespace. Some channel types, like ppp_async and ppp_synctty, can have their userspace controller running in a different namespace. Therefore they can't rely on them to preclude their netns from being removed from under them. ================================================================== BUG: KASAN: use-after-free in ppp_unregister_channel+0x372/0x3a0 at addr ffff880064e217e0 Read of size 8 by task syz-executor/11581 ============================================================================= BUG net_namespace (Not tainted): kasan: bad access detected ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in copy_net_ns+0x6b/0x1a0 age=92569 cpu=3 pid=6906 [< none >] ___slab_alloc+0x4c7/0x500 kernel/mm/slub.c:2440 [< none >] __slab_alloc+0x4c/0x90 kernel/mm/slub.c:2469 [< inline >] slab_alloc_node kernel/mm/slub.c:2532 [< inline >] slab_alloc kernel/mm/slub.c:2574 [< none >] kmem_cache_alloc+0x23a/0x2b0 kernel/mm/slub.c:2579 [< inline >] kmem_cache_zalloc kernel/include/linux/slab.h:597 [< inline >] net_alloc kernel/net/core/net_namespace.c:325 [< none >] copy_net_ns+0x6b/0x1a0 kernel/net/core/net_namespace.c:360 [< none >] create_new_namespaces+0x2f6/0x610 kernel/kernel/nsproxy.c:95 [< none >] copy_namespaces+0x297/0x320 kernel/kernel/nsproxy.c:150 [< none >] copy_process.part.35+0x1bf4/0x5760 kernel/kernel/fork.c:1451 [< inline >] copy_process kernel/kernel/fork.c:1274 [< none >] _do_fork+0x1bc/0xcb0 kernel/kernel/fork.c:1723 [< inline >] SYSC_clone kernel/kernel/fork.c:1832 [< none >] SyS_clone+0x37/0x50 kernel/kernel/fork.c:1826 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a kernel/arch/x86/entry/entry_64.S:185 INFO: Freed in net_drop_ns+0x67/0x80 age=575 cpu=2 pid=2631 [< none >] __slab_free+0x1fc/0x320 kernel/mm/slub.c:2650 [< inline >] slab_free kernel/mm/slub.c:2805 [< none >] kmem_cache_free+0x2a0/0x330 kernel/mm/slub.c:2814 [< inline >] net_free kernel/net/core/net_namespace.c:341 [< none >] net_drop_ns+0x67/0x80 kernel/net/core/net_namespace.c:348 [< none >] cleanup_net+0x4e5/0x600 kernel/net/core/net_namespace.c:448 [< none >] process_one_work+0x794/0x1440 kernel/kernel/workqueue.c:2036 [< none >] worker_thread+0xdb/0xfc0 kernel/kernel/workqueue.c:2170 [< none >] kthread+0x23f/0x2d0 kernel/drivers/block/aoe/aoecmd.c:1303 [< none >] ret_from_fork+0x3f/0x70 kernel/arch/x86/entry/entry_64.S:468 INFO: Slab 0xffffea0001938800 objects=3 used=0 fp=0xffff880064e20000 flags=0x5fffc0000004080 INFO: Object 0xffff880064e20000 @offset=0 fp=0xffff880064e24200 CPU: 1 PID: 11581 Comm: syz-executor Tainted: G B 4.4.0+ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 00000000ffffffff ffff8800662c7790 ffffffff8292049d ffff88003e36a300 ffff880064e20000 ffff880064e20000 ffff8800662c77c0 ffffffff816f2054 ffff88003e36a300 ffffea0001938800 ffff880064e20000 0000000000000000 Call Trace: [< inline >] __dump_stack kernel/lib/dump_stack.c:15 [<ffffffff8292049d>] dump_stack+0x6f/0xa2 kernel/lib/dump_stack.c:50 [<ffffffff816f2054>] print_trailer+0xf4/0x150 kernel/mm/slub.c:654 [<ffffffff816f875f>] object_err+0x2f/0x40 kernel/mm/slub.c:661 [< inline >] print_address_description kernel/mm/kasan/report.c:138 [<ffffffff816fb0c5>] kasan_report_error+0x215/0x530 kernel/mm/kasan/report.c:236 [< inline >] kasan_report kernel/mm/kasan/report.c:259 [<ffffffff816fb4de>] __asan_report_load8_noabort+0x3e/0x40 kernel/mm/kasan/report.c:280 [< inline >] ? ppp_pernet kernel/include/linux/compiler.h:218 [<ffffffff83ad71b2>] ? ppp_unregister_channel+0x372/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392 [< inline >] ppp_pernet kernel/include/linux/compiler.h:218 [<ffffffff83ad71b2>] ppp_unregister_channel+0x372/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392 [< inline >] ? ppp_pernet kernel/drivers/net/ppp/ppp_generic.c:293 [<ffffffff83ad6f26>] ? ppp_unregister_channel+0xe6/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392 [<ffffffff83ae18f3>] ppp_asynctty_close+0xa3/0x130 kernel/drivers/net/ppp/ppp_async.c:241 [<ffffffff83ae1850>] ? async_lcp_peek+0x5b0/0x5b0 kernel/drivers/net/ppp/ppp_async.c:1000 [<ffffffff82c33239>] tty_ldisc_close.isra.1+0x99/0xe0 kernel/drivers/tty/tty_ldisc.c:478 [<ffffffff82c332c0>] tty_ldisc_kill+0x40/0x170 kernel/drivers/tty/tty_ldisc.c:744 [<ffffffff82c34943>] tty_ldisc_release+0x1b3/0x260 kernel/drivers/tty/tty_ldisc.c:772 [<ffffffff82c1ef21>] tty_release+0xac1/0x13e0 kernel/drivers/tty/tty_io.c:1901 [<ffffffff82c1e460>] ? release_tty+0x320/0x320 kernel/drivers/tty/tty_io.c:1688 [<ffffffff8174de36>] __fput+0x236/0x780 kernel/fs/file_table.c:208 [<ffffffff8174e405>] ____fput+0x15/0x20 kernel/fs/file_table.c:244 [<ffffffff813595ab>] task_work_run+0x16b/0x200 kernel/kernel/task_work.c:115 [< inline >] exit_task_work kernel/include/linux/task_work.h:21 [<ffffffff81307105>] do_exit+0x8b5/0x2c60 kernel/kernel/exit.c:750 [<ffffffff813fdd20>] ? debug_check_no_locks_freed+0x290/0x290 kernel/kernel/locking/lockdep.c:4123 [<ffffffff81306850>] ? mm_update_next_owner+0x6f0/0x6f0 kernel/kernel/exit.c:357 [<ffffffff813215e6>] ? __dequeue_signal+0x136/0x470 kernel/kernel/signal.c:550 [<ffffffff8132067b>] ? recalc_sigpending_tsk+0x13b/0x180 kernel/kernel/signal.c:145 [<ffffffff81309628>] do_group_exit+0x108/0x330 kernel/kernel/exit.c:880 [<ffffffff8132b9d4>] get_signal+0x5e4/0x14f0 kernel/kernel/signal.c:2307 [< inline >] ? kretprobe_table_lock kernel/kernel/kprobes.c:1113 [<ffffffff8151d355>] ? kprobe_flush_task+0xb5/0x450 kernel/kernel/kprobes.c:1158 [<ffffffff8115f7d3>] do_signal+0x83/0x1c90 kernel/arch/x86/kernel/signal.c:712 [<ffffffff8151d2a0>] ? recycle_rp_inst+0x310/0x310 kernel/include/linux/list.h:655 [<ffffffff8115f750>] ? setup_sigcontext+0x780/0x780 kernel/arch/x86/kernel/signal.c:165 [<ffffffff81380864>] ? finish_task_switch+0x424/0x5f0 kernel/kernel/sched/core.c:2692 [< inline >] ? finish_lock_switch kernel/kernel/sched/sched.h:1099 [<ffffffff81380560>] ? finish_task_switch+0x120/0x5f0 kernel/kernel/sched/core.c:2678 [< inline >] ? context_switch kernel/kernel/sched/core.c:2807 [<ffffffff85d794e9>] ? __schedule+0x919/0x1bd0 kernel/kernel/sched/core.c:3283 [<ffffffff81003901>] exit_to_usermode_loop+0xf1/0x1a0 kernel/arch/x86/entry/common.c:247 [< inline >] prepare_exit_to_usermode kernel/arch/x86/entry/common.c:282 [<ffffffff810062ef>] syscall_return_slowpath+0x19f/0x210 kernel/arch/x86/entry/common.c:344 [<ffffffff85d88022>] int_ret_from_sys_call+0x25/0x9f kernel/arch/x86/entry/entry_64.S:281 Memory state around the buggy address: ffff880064e21680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880064e21700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880064e21780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880064e21800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880064e21880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Fixes: 273ec51dd7ce ("net: ppp_generic - introduce net-namespace functionality v2") Reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu> 
commit 1f461dcdd296eecedaffffc6bae2bfa90bd7eb89 upstream.

Let channels hold a reference on their network namespace.
Some channel types, like ppp_async and ppp_synctty, can have their
userspace controller running in a different namespace. Therefore they
can't rely on them to preclude their netns from being removed from
under them.

==================================================================
BUG: KASAN: use-after-free in ppp_unregister_channel+0x372/0x3a0 at
addr ffff880064e217e0
Read of size 8 by task syz-executor/11581
=============================================================================
BUG net_namespace (Not tainted): kasan: bad access detected
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Allocated in copy_net_ns+0x6b/0x1a0 age=92569 cpu=3 pid=6906
[<      none      >] ___slab_alloc+0x4c7/0x500 kernel/mm/slub.c:2440
[<      none      >] __slab_alloc+0x4c/0x90 kernel/mm/slub.c:2469
[<     inline     >] slab_alloc_node kernel/mm/slub.c:2532
[<     inline     >] slab_alloc kernel/mm/slub.c:2574
[<      none      >] kmem_cache_alloc+0x23a/0x2b0 kernel/mm/slub.c:2579
[<     inline     >] kmem_cache_zalloc kernel/include/linux/slab.h:597
[<     inline     >] net_alloc kernel/net/core/net_namespace.c:325
[<      none      >] copy_net_ns+0x6b/0x1a0 kernel/net/core/net_namespace.c:360
[<      none      >] create_new_namespaces+0x2f6/0x610 kernel/kernel/nsproxy.c:95
[<      none      >] copy_namespaces+0x297/0x320 kernel/kernel/nsproxy.c:150
[<      none      >] copy_process.part.35+0x1bf4/0x5760 kernel/kernel/fork.c:1451
[<     inline     >] copy_process kernel/kernel/fork.c:1274
[<      none      >] _do_fork+0x1bc/0xcb0 kernel/kernel/fork.c:1723
[<     inline     >] SYSC_clone kernel/kernel/fork.c:1832
[<      none      >] SyS_clone+0x37/0x50 kernel/kernel/fork.c:1826
[<      none      >] entry_SYSCALL_64_fastpath+0x16/0x7a kernel/arch/x86/entry/entry_64.S:185

INFO: Freed in net_drop_ns+0x67/0x80 age=575 cpu=2 pid=2631
[<      none      >] __slab_free+0x1fc/0x320 kernel/mm/slub.c:2650
[<     inline     >] slab_free kernel/mm/slub.c:2805
[<      none      >] kmem_cache_free+0x2a0/0x330 kernel/mm/slub.c:2814
[<     inline     >] net_free kernel/net/core/net_namespace.c:341
[<      none      >] net_drop_ns+0x67/0x80 kernel/net/core/net_namespace.c:348
[<      none      >] cleanup_net+0x4e5/0x600 kernel/net/core/net_namespace.c:448
[<      none      >] process_one_work+0x794/0x1440 kernel/kernel/workqueue.c:2036
[<      none      >] worker_thread+0xdb/0xfc0 kernel/kernel/workqueue.c:2170
[<      none      >] kthread+0x23f/0x2d0 kernel/drivers/block/aoe/aoecmd.c:1303
[<      none      >] ret_from_fork+0x3f/0x70 kernel/arch/x86/entry/entry_64.S:468
INFO: Slab 0xffffea0001938800 objects=3 used=0 fp=0xffff880064e20000
flags=0x5fffc0000004080
INFO: Object 0xffff880064e20000 @offset=0 fp=0xffff880064e24200

CPU: 1 PID: 11581 Comm: syz-executor Tainted: G    B           4.4.0+
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014
 00000000ffffffff ffff8800662c7790 ffffffff8292049d ffff88003e36a300
 ffff880064e20000 ffff880064e20000 ffff8800662c77c0 ffffffff816f2054
 ffff88003e36a300 ffffea0001938800 ffff880064e20000 0000000000000000
Call Trace:
 [<     inline     >] __dump_stack kernel/lib/dump_stack.c:15
 [<ffffffff8292049d>] dump_stack+0x6f/0xa2 kernel/lib/dump_stack.c:50
 [<ffffffff816f2054>] print_trailer+0xf4/0x150 kernel/mm/slub.c:654
 [<ffffffff816f875f>] object_err+0x2f/0x40 kernel/mm/slub.c:661
 [<     inline     >] print_address_description kernel/mm/kasan/report.c:138
 [<ffffffff816fb0c5>] kasan_report_error+0x215/0x530 kernel/mm/kasan/report.c:236
 [<     inline     >] kasan_report kernel/mm/kasan/report.c:259
 [<ffffffff816fb4de>] __asan_report_load8_noabort+0x3e/0x40 kernel/mm/kasan/report.c:280
 [<     inline     >] ? ppp_pernet kernel/include/linux/compiler.h:218
 [<ffffffff83ad71b2>] ? ppp_unregister_channel+0x372/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392
 [<     inline     >] ppp_pernet kernel/include/linux/compiler.h:218
 [<ffffffff83ad71b2>] ppp_unregister_channel+0x372/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392
 [<     inline     >] ? ppp_pernet kernel/drivers/net/ppp/ppp_generic.c:293
 [<ffffffff83ad6f26>] ? ppp_unregister_channel+0xe6/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392
 [<ffffffff83ae18f3>] ppp_asynctty_close+0xa3/0x130 kernel/drivers/net/ppp/ppp_async.c:241
 [<ffffffff83ae1850>] ? async_lcp_peek+0x5b0/0x5b0 kernel/drivers/net/ppp/ppp_async.c:1000
 [<ffffffff82c33239>] tty_ldisc_close.isra.1+0x99/0xe0 kernel/drivers/tty/tty_ldisc.c:478
 [<ffffffff82c332c0>] tty_ldisc_kill+0x40/0x170 kernel/drivers/tty/tty_ldisc.c:744
 [<ffffffff82c34943>] tty_ldisc_release+0x1b3/0x260 kernel/drivers/tty/tty_ldisc.c:772
 [<ffffffff82c1ef21>] tty_release+0xac1/0x13e0 kernel/drivers/tty/tty_io.c:1901
 [<ffffffff82c1e460>] ? release_tty+0x320/0x320 kernel/drivers/tty/tty_io.c:1688
 [<ffffffff8174de36>] __fput+0x236/0x780 kernel/fs/file_table.c:208
 [<ffffffff8174e405>] ____fput+0x15/0x20 kernel/fs/file_table.c:244
 [<ffffffff813595ab>] task_work_run+0x16b/0x200 kernel/kernel/task_work.c:115
 [<     inline     >] exit_task_work kernel/include/linux/task_work.h:21
 [<ffffffff81307105>] do_exit+0x8b5/0x2c60 kernel/kernel/exit.c:750
 [<ffffffff813fdd20>] ? debug_check_no_locks_freed+0x290/0x290 kernel/kernel/locking/lockdep.c:4123
 [<ffffffff81306850>] ? mm_update_next_owner+0x6f0/0x6f0 kernel/kernel/exit.c:357
 [<ffffffff813215e6>] ? __dequeue_signal+0x136/0x470 kernel/kernel/signal.c:550
 [<ffffffff8132067b>] ? recalc_sigpending_tsk+0x13b/0x180 kernel/kernel/signal.c:145
 [<ffffffff81309628>] do_group_exit+0x108/0x330 kernel/kernel/exit.c:880
 [<ffffffff8132b9d4>] get_signal+0x5e4/0x14f0 kernel/kernel/signal.c:2307
 [<     inline     >] ? kretprobe_table_lock kernel/kernel/kprobes.c:1113
 [<ffffffff8151d355>] ? kprobe_flush_task+0xb5/0x450 kernel/kernel/kprobes.c:1158
 [<ffffffff8115f7d3>] do_signal+0x83/0x1c90 kernel/arch/x86/kernel/signal.c:712
 [<ffffffff8151d2a0>] ? recycle_rp_inst+0x310/0x310 kernel/include/linux/list.h:655
 [<ffffffff8115f750>] ? setup_sigcontext+0x780/0x780 kernel/arch/x86/kernel/signal.c:165
 [<ffffffff81380864>] ? finish_task_switch+0x424/0x5f0 kernel/kernel/sched/core.c:2692
 [<     inline     >] ? finish_lock_switch kernel/kernel/sched/sched.h:1099
 [<ffffffff81380560>] ? finish_task_switch+0x120/0x5f0 kernel/kernel/sched/core.c:2678
 [<     inline     >] ? context_switch kernel/kernel/sched/core.c:2807
 [<ffffffff85d794e9>] ? __schedule+0x919/0x1bd0 kernel/kernel/sched/core.c:3283
 [<ffffffff81003901>] exit_to_usermode_loop+0xf1/0x1a0 kernel/arch/x86/entry/common.c:247
 [<     inline     >] prepare_exit_to_usermode kernel/arch/x86/entry/common.c:282
 [<ffffffff810062ef>] syscall_return_slowpath+0x19f/0x210 kernel/arch/x86/entry/common.c:344
 [<ffffffff85d88022>] int_ret_from_sys_call+0x25/0x9f kernel/arch/x86/entry/entry_64.S:281
Memory state around the buggy address:
 ffff880064e21680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff880064e21700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff880064e21780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff880064e21800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff880064e21880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Fixes: 273ec51dd7ce ("net: ppp_generic - introduce net-namespace functionality v2")
Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
ppp, slip: Validate VJ compression slot parameters completely 2016-01-29T05:49:35+00:00 Ben Hutchings ben@decadent.org.uk 2015-11-01T16:22:53+00:00 f82699de104eaf8a7ffc2849a566a94818dd8a3c [ Upstream commit 4ab42d78e37a294ac7bc56901d563c642e03c4ae ] Currently slhc_init() treats out-of-range values of rslots and tslots as equivalent to 0, except that if tslots is too large it will dereference a null pointer (CVE-2015-7799). Add a range-check at the top of the function and make it return an ERR_PTR() on error instead of NULL. Change the callers accordingly. Compile-tested only. Reported-by: 郭永刚 <guoyonggang@360.cn> References: http://article.gmane.org/gmane.comp.security.oss.general/17908 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 4ab42d78e37a294ac7bc56901d563c642e03c4ae ]

Currently slhc_init() treats out-of-range values of rslots and tslots
as equivalent to 0, except that if tslots is too large it will
dereference a null pointer (CVE-2015-7799).

Add a range-check at the top of the function and make it return an
ERR_PTR() on error instead of NULL.  Change the callers accordingly.

Compile-tested only.

Reported-by: 郭永刚 <guoyonggang@360.cn>
References: http://article.gmane.org/gmane.comp.security.oss.general/17908
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pptp: verify sockaddr_len in pptp_bind() and pptp_connect() 2016-01-23T03:47:55+00:00 WANG Cong xiyou.wangcong@gmail.com 2015-12-14T21:48:36+00:00 83f2b0860770d05f14cb8ce29ffd18f2f5585a4e [ Upstream commit 09ccfd238e5a0e670d8178cf50180ea81ae09ae1 ] Reported-by: Dmitry Vyukov <dvyukov@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 09ccfd238e5a0e670d8178cf50180ea81ae09ae1 ]

Reported-by: Dmitry Vyukov <dvyukov@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ppp: fix pppoe_dev deletion condition in pppoe_release() 2015-12-09T18:40:06+00:00 Guillaume Nault g.nault@alphalink.fr 2015-10-22T14:57:10+00:00 e42f6b5c7bcf22062a389d40cbf2a723aab4d2df [ Upstream commit 1acea4f6ce1b1c0941438aca75dd2e5c6b09db60 ] We can't rely on PPPOX_ZOMBIE to decide whether to clear po->pppoe_dev. PPPOX_ZOMBIE can be set by pppoe_disc_rcv() even when po->pppoe_dev is NULL. So we have no guarantee that (sk->sk_state & PPPOX_ZOMBIE) implies (po->pppoe_dev != NULL). Since we're releasing a PPPoE socket, we want to release the pppoe_dev if it exists and reset sk_state to PPPOX_DEAD, no matter the previous value of sk_state. So we can just check for po->pppoe_dev and avoid any assumption on sk->sk_state. Fixes: 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 1acea4f6ce1b1c0941438aca75dd2e5c6b09db60 ]

We can't rely on PPPOX_ZOMBIE to decide whether to clear po->pppoe_dev.
PPPOX_ZOMBIE can be set by pppoe_disc_rcv() even when po->pppoe_dev is
NULL. So we have no guarantee that (sk->sk_state & PPPOX_ZOMBIE) implies
(po->pppoe_dev != NULL).
Since we're releasing a PPPoE socket, we want to release the pppoe_dev
if it exists and reset sk_state to PPPOX_DEAD, no matter the previous
value of sk_state. So we can just check for po->pppoe_dev and avoid any
assumption on sk->sk_state.

Fixes: 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ppp: don't override sk->sk_state in pppoe_flush_dev() 2015-10-27T00:44:48+00:00 Guillaume Nault g.nault@alphalink.fr 2015-09-30T09:45:33+00:00 9db7ed146a62e3c66a8a7263fdf4adb5c48d16ca [ Upstream commit e6740165b8f7f06d8caee0fceab3fb9d790a6fed ] Since commit 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release"), pppoe_release() calls dev_put(po->pppoe_dev) if sk is in the PPPOX_ZOMBIE state. But pppoe_flush_dev() can set sk->sk_state to PPPOX_ZOMBIE _and_ reset po->pppoe_dev to NULL. This leads to the following oops: [ 570.140800] BUG: unable to handle kernel NULL pointer dereference at 00000000000004e0 [ 570.142931] IP: [<ffffffffa018c701>] pppoe_release+0x50/0x101 [pppoe] [ 570.144601] PGD 3d119067 PUD 3dbc1067 PMD 0 [ 570.144601] Oops: 0000 [#1] SMP [ 570.144601] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6_udp_tunnel udp_tunnel pppoe pppox ppp_generic slhc loop crc32c_intel ghash_clmulni_intel jitterentropy_rng sha256_generic hmac drbg ansi_cprng aesni_intel aes_x86_64 ablk_helper cryptd lrw gf128mul glue_helper acpi_cpufreq evdev serio_raw processor button ext4 crc16 mbcache jbd2 virtio_net virtio_blk virtio_pci virtio_ring virtio [ 570.144601] CPU: 1 PID: 15738 Comm: ppp-apitest Not tainted 4.2.0 #1 [ 570.144601] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 570.144601] task: ffff88003d30d600 ti: ffff880036b60000 task.ti: ffff880036b60000 [ 570.144601] RIP: 0010:[<ffffffffa018c701>] [<ffffffffa018c701>] pppoe_release+0x50/0x101 [pppoe] [ 570.144601] RSP: 0018:ffff880036b63e08 EFLAGS: 00010202 [ 570.144601] RAX: 0000000000000000 RBX: ffff880034340000 RCX: 0000000000000206 [ 570.144601] RDX: 0000000000000006 RSI: ffff88003d30dd20 RDI: ffff88003d30dd20 [ 570.144601] RBP: ffff880036b63e28 R08: 0000000000000001 R09: 0000000000000000 [ 570.144601] R10: 00007ffee9b50420 R11: ffff880034340078 R12: ffff8800387ec780 [ 570.144601] R13: ffff8800387ec7b0 R14: ffff88003e222aa0 R15: ffff8800387ec7b0 [ 570.144601] FS: 00007f5672f48700(0000) GS:ffff88003fc80000(0000) knlGS:0000000000000000 [ 570.144601] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 570.144601] CR2: 00000000000004e0 CR3: 0000000037f7e000 CR4: 00000000000406a0 [ 570.144601] Stack: [ 570.144601] ffffffffa018f240 ffff8800387ec780 ffffffffa018f240 ffff8800387ec7b0 [ 570.144601] ffff880036b63e48 ffffffff812caabe ffff880039e4e000 0000000000000008 [ 570.144601] ffff880036b63e58 ffffffff812cabad ffff880036b63ea8 ffffffff811347f5 [ 570.144601] Call Trace: [ 570.144601] [<ffffffff812caabe>] sock_release+0x1a/0x75 [ 570.144601] [<ffffffff812cabad>] sock_close+0xd/0x11 [ 570.144601] [<ffffffff811347f5>] __fput+0xff/0x1a5 [ 570.144601] [<ffffffff811348cb>] ____fput+0x9/0xb [ 570.144601] [<ffffffff81056682>] task_work_run+0x66/0x90 [ 570.144601] [<ffffffff8100189e>] prepare_exit_to_usermode+0x8c/0xa7 [ 570.144601] [<ffffffff81001a26>] syscall_return_slowpath+0x16d/0x19b [ 570.144601] [<ffffffff813babb1>] int_ret_from_sys_call+0x25/0x9f [ 570.144601] Code: 48 8b 83 c8 01 00 00 a8 01 74 12 48 89 df e8 8b 27 14 e1 b8 f7 ff ff ff e9 b7 00 00 00 8a 43 12 a8 0b 74 1c 48 8b 83 a8 04 00 00 <48> 8b 80 e0 04 00 00 65 ff 08 48 c7 83 a8 04 00 00 00 00 00 00 [ 570.144601] RIP [<ffffffffa018c701>] pppoe_release+0x50/0x101 [pppoe] [ 570.144601] RSP <ffff880036b63e08> [ 570.144601] CR2: 00000000000004e0 [ 570.200518] ---[ end trace 46956baf17349563 ]--- pppoe_flush_dev() has no reason to override sk->sk_state with PPPOX_ZOMBIE. pppox_unbind_sock() already sets sk->sk_state to PPPOX_DEAD, which is the correct state given that sk is unbound and po->pppoe_dev is NULL. Fixes: 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release") Tested-by: Oleksii Berezhniak <core@irc.lg.ua> Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e6740165b8f7f06d8caee0fceab3fb9d790a6fed ]

Since commit 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release"),
pppoe_release() calls dev_put(po->pppoe_dev) if sk is in the
PPPOX_ZOMBIE state. But pppoe_flush_dev() can set sk->sk_state to
PPPOX_ZOMBIE _and_ reset po->pppoe_dev to NULL. This leads to the
following oops:

[  570.140800] BUG: unable to handle kernel NULL pointer dereference at 00000000000004e0
[  570.142931] IP: [<ffffffffa018c701>] pppoe_release+0x50/0x101 [pppoe]
[  570.144601] PGD 3d119067 PUD 3dbc1067 PMD 0
[  570.144601] Oops: 0000 [#1] SMP
[  570.144601] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6_udp_tunnel udp_tunnel pppoe pppox ppp_generic slhc loop crc32c_intel ghash_clmulni_intel jitterentropy_rng sha256_generic hmac drbg ansi_cprng aesni_intel aes_x86_64 ablk_helper cryptd lrw gf128mul glue_helper acpi_cpufreq evdev serio_raw processor button ext4 crc16 mbcache jbd2 virtio_net virtio_blk virtio_pci virtio_ring virtio
[  570.144601] CPU: 1 PID: 15738 Comm: ppp-apitest Not tainted 4.2.0 #1
[  570.144601] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[  570.144601] task: ffff88003d30d600 ti: ffff880036b60000 task.ti: ffff880036b60000
[  570.144601] RIP: 0010:[<ffffffffa018c701>]  [<ffffffffa018c701>] pppoe_release+0x50/0x101 [pppoe]
[  570.144601] RSP: 0018:ffff880036b63e08  EFLAGS: 00010202
[  570.144601] RAX: 0000000000000000 RBX: ffff880034340000 RCX: 0000000000000206
[  570.144601] RDX: 0000000000000006 RSI: ffff88003d30dd20 RDI: ffff88003d30dd20
[  570.144601] RBP: ffff880036b63e28 R08: 0000000000000001 R09: 0000000000000000
[  570.144601] R10: 00007ffee9b50420 R11: ffff880034340078 R12: ffff8800387ec780
[  570.144601] R13: ffff8800387ec7b0 R14: ffff88003e222aa0 R15: ffff8800387ec7b0
[  570.144601] FS:  00007f5672f48700(0000) GS:ffff88003fc80000(0000) knlGS:0000000000000000
[  570.144601] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  570.144601] CR2: 00000000000004e0 CR3: 0000000037f7e000 CR4: 00000000000406a0
[  570.144601] Stack:
[  570.144601]  ffffffffa018f240 ffff8800387ec780 ffffffffa018f240 ffff8800387ec7b0
[  570.144601]  ffff880036b63e48 ffffffff812caabe ffff880039e4e000 0000000000000008
[  570.144601]  ffff880036b63e58 ffffffff812cabad ffff880036b63ea8 ffffffff811347f5
[  570.144601] Call Trace:
[  570.144601]  [<ffffffff812caabe>] sock_release+0x1a/0x75
[  570.144601]  [<ffffffff812cabad>] sock_close+0xd/0x11
[  570.144601]  [<ffffffff811347f5>] __fput+0xff/0x1a5
[  570.144601]  [<ffffffff811348cb>] ____fput+0x9/0xb
[  570.144601]  [<ffffffff81056682>] task_work_run+0x66/0x90
[  570.144601]  [<ffffffff8100189e>] prepare_exit_to_usermode+0x8c/0xa7
[  570.144601]  [<ffffffff81001a26>] syscall_return_slowpath+0x16d/0x19b
[  570.144601]  [<ffffffff813babb1>] int_ret_from_sys_call+0x25/0x9f
[  570.144601] Code: 48 8b 83 c8 01 00 00 a8 01 74 12 48 89 df e8 8b 27 14 e1 b8 f7 ff ff ff e9 b7 00 00 00 8a 43 12 a8 0b 74 1c 48 8b 83 a8 04 00 00 <48> 8b 80 e0 04 00 00 65 ff 08 48 c7 83 a8 04 00 00 00 00 00 00
[  570.144601] RIP  [<ffffffffa018c701>] pppoe_release+0x50/0x101 [pppoe]
[  570.144601]  RSP <ffff880036b63e08>
[  570.144601] CR2: 00000000000004e0
[  570.200518] ---[ end trace 46956baf17349563 ]---

pppoe_flush_dev() has no reason to override sk->sk_state with
PPPOX_ZOMBIE. pppox_unbind_sock() already sets sk->sk_state to
PPPOX_DEAD, which is the correct state given that sk is unbound and
po->pppoe_dev is NULL.

Fixes: 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release")
Tested-by: Oleksii Berezhniak <core@irc.lg.ua>
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ppp: deflate: never return len larger than output buffer 2015-02-27T01:48:48+00:00 Florian Westphal fw@strlen.de 2015-01-28T09:56:04+00:00 a7df378ab94e59b29128b6d6b95da9fd67b40337 [ Upstream commit e2a4800e75780ccf4e6c2487f82b688ba736eb18 ] When we've run out of space in the output buffer to store more data, we will call zlib_deflate with a NULL output buffer until we've consumed remaining input. When this happens, olen contains the size the output buffer would have consumed iff we'd have had enough room. This can later cause skb_over_panic when ppp_generic skb_put()s the returned length. Reported-by: Iain Douglas <centos@1n6.org.uk> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e2a4800e75780ccf4e6c2487f82b688ba736eb18 ]

When we've run out of space in the output buffer to store more data, we
will call zlib_deflate with a NULL output buffer until we've consumed
remaining input.

When this happens, olen contains the size the output buffer would have
consumed iff we'd have had enough room.

This can later cause skb_over_panic when ppp_generic skb_put()s
the returned length.

Reported-by: Iain Douglas <centos@1n6.org.uk>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pptp: fix stack info leak in pptp_getname() 2014-12-06T23:05:47+00:00 Mathias Krause minipli@googlemail.com 2014-11-19T17:05:26+00:00 f0eed5a220e777b9e01b9eb45d7e387a35f1f6fa [ Upstream commit a5f6fc28d6e6cc379c6839f21820e62262419584 ] pptp_getname() only partially initializes the stack variable sa, particularly only fills the pptp part of the sa_addr union. The code thereby discloses 16 bytes of kernel stack memory via getsockname(). Fix this by memset(0)'ing the union before. Cc: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a5f6fc28d6e6cc379c6839f21820e62262419584 ]

pptp_getname() only partially initializes the stack variable sa,
particularly only fills the pptp part of the sa_addr union. The code
thereby discloses 16 bytes of kernel stack memory via getsockname().

Fix this by memset(0)'ing the union before.

Cc: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fix misuses of f_count() in ppp and netlink 2014-11-14T16:47:55+00:00 Al Viro viro@zeniv.linux.org.uk 2014-10-09T03:44:00+00:00 0af0e1dba97dc53b9f14795ca49b0b1b24aa0ce1 commit 24dff96a37a2ca319e75a74d3929b2de22447ca6 upstream. we used to check for "nobody else could start doing anything with that opened file" by checking that refcount was 2 or less - one for descriptor table and one we'd acquired in fget() on the way to wherever we are. That was race-prone (somebody else might have had a reference to descriptor table and do fget() just as we'd been checking) and it had become flat-out incorrect back when we switched to fget_light() on those codepaths - unlike fget(), it doesn't grab an extra reference unless the descriptor table is shared. The same change allowed a race-free check, though - we are safe exactly when refcount is less than 2. It was a long time ago; pre-2.6.12 for ioctl() (the codepath leading to ppp one) and 2.6.17 for sendmsg() (netlink one). OTOH, netlink hadn't grown that check until 3.9 and ppp used to live in drivers/net, not drivers/net/ppp until 3.1. The bug existed well before that, though, and the same fix used to apply in old location of file. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 24dff96a37a2ca319e75a74d3929b2de22447ca6 upstream.

we used to check for "nobody else could start doing anything with
that opened file" by checking that refcount was 2 or less - one
for descriptor table and one we'd acquired in fget() on the way to
wherever we are.  That was race-prone (somebody else might have
had a reference to descriptor table and do fget() just as we'd
been checking) and it had become flat-out incorrect back when
we switched to fget_light() on those codepaths - unlike fget(),
it doesn't grab an extra reference unless the descriptor table
is shared.  The same change allowed a race-free check, though -
we are safe exactly when refcount is less than 2.

It was a long time ago; pre-2.6.12 for ioctl() (the codepath leading
to ppp one) and 2.6.17 for sendmsg() (netlink one).  OTOH,
netlink hadn't grown that check until 3.9 and ppp used to live
in drivers/net, not drivers/net/ppp until 3.1.  The bug existed
well before that, though, and the same fix used to apply in old
location of file.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
inetpeer: get rid of ip_id_count 2014-08-14T01:24:15+00:00 Eric Dumazet edumazet@google.com 2014-06-02T12:26:03+00:00 ff1f69a89a613223c57c13190a6c9be928ac4b9d [ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ] Ideally, we would need to generate IP ID using a per destination IP generator. linux kernels used inet_peer cache for this purpose, but this had a huge cost on servers disabling MTU discovery. 1) each inet_peer struct consumes 192 bytes 2) inetpeer cache uses a binary tree of inet_peer structs, with a nominal size of ~66000 elements under load. 3) lookups in this tree are hitting a lot of cache lines, as tree depth is about 20. 4) If server deals with many tcp flows, we have a high probability of not finding the inet_peer, allocating a fresh one, inserting it in the tree with same initial ip_id_count, (cf secure_ip_id()) 5) We garbage collect inet_peer aggressively. IP ID generation do not have to be 'perfect' Goal is trying to avoid duplicates in a short period of time, so that reassembly units have a chance to complete reassembly of fragments belonging to one message before receiving other fragments with a recycled ID. We simply use an array of generators, and a Jenkin hash using the dst IP as a key. ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it belongs (it is only used from this file) secure_ip_id() and secure_ipv6_id() no longer are needed. Rename ip_select_ident_more() to ip_select_ident_segs() to avoid unnecessary decrement/increment of the number of segments. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>