BMC/Intel-BMC/linux.git/drivers/net/ppp/ppp_generic.c, branch dev-4.4

ppp: take reference on channels netns

2016-04-20T06:42:05+00:00

[ Upstream commit 1f461dcdd296eecedaffffc6bae2bfa90bd7eb89 ] 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 [] dump_stack+0x6f/0xa2 kernel/lib/dump_stack.c:50 [] print_trailer+0xf4/0x150 kernel/mm/slub.c:654 [] object_err+0x2f/0x40 kernel/mm/slub.c:661 [< inline >] print_address_description kernel/mm/kasan/report.c:138 [] kasan_report_error+0x215/0x530 kernel/mm/kasan/report.c:236 [< inline >] kasan_report kernel/mm/kasan/report.c:259 [] __asan_report_load8_noabort+0x3e/0x40 kernel/mm/kasan/report.c:280 [< inline >] ? ppp_pernet kernel/include/linux/compiler.h:218 [] ? ppp_unregister_channel+0x372/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392 [< inline >] ppp_pernet kernel/include/linux/compiler.h:218 [] ppp_unregister_channel+0x372/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392 [< inline >] ? ppp_pernet kernel/drivers/net/ppp/ppp_generic.c:293 [] ? ppp_unregister_channel+0xe6/0x3a0 kernel/drivers/net/ppp/ppp_generic.c:2392 [] ppp_asynctty_close+0xa3/0x130 kernel/drivers/net/ppp/ppp_async.c:241 [] ? async_lcp_peek+0x5b0/0x5b0 kernel/drivers/net/ppp/ppp_async.c:1000 [] tty_ldisc_close.isra.1+0x99/0xe0 kernel/drivers/tty/tty_ldisc.c:478 [] tty_ldisc_kill+0x40/0x170 kernel/drivers/tty/tty_ldisc.c:744 [] tty_ldisc_release+0x1b3/0x260 kernel/drivers/tty/tty_ldisc.c:772 [] tty_release+0xac1/0x13e0 kernel/drivers/tty/tty_io.c:1901 [] ? release_tty+0x320/0x320 kernel/drivers/tty/tty_io.c:1688 [] __fput+0x236/0x780 kernel/fs/file_table.c:208 [] ____fput+0x15/0x20 kernel/fs/file_table.c:244 [] task_work_run+0x16b/0x200 kernel/kernel/task_work.c:115 [< inline >] exit_task_work kernel/include/linux/task_work.h:21 [] do_exit+0x8b5/0x2c60 kernel/kernel/exit.c:750 [] ? debug_check_no_locks_freed+0x290/0x290 kernel/kernel/locking/lockdep.c:4123 [] ? mm_update_next_owner+0x6f0/0x6f0 kernel/kernel/exit.c:357 [] ? __dequeue_signal+0x136/0x470 kernel/kernel/signal.c:550 [] ? recalc_sigpending_tsk+0x13b/0x180 kernel/kernel/signal.c:145 [] do_group_exit+0x108/0x330 kernel/kernel/exit.c:880 [] get_signal+0x5e4/0x14f0 kernel/kernel/signal.c:2307 [< inline >] ? kretprobe_table_lock kernel/kernel/kprobes.c:1113 [] ? kprobe_flush_task+0xb5/0x450 kernel/kernel/kprobes.c:1158 [] do_signal+0x83/0x1c90 kernel/arch/x86/kernel/signal.c:712 [] ? recycle_rp_inst+0x310/0x310 kernel/include/linux/list.h:655 [] ? setup_sigcontext+0x780/0x780 kernel/arch/x86/kernel/signal.c:165 [] ? finish_task_switch+0x424/0x5f0 kernel/kernel/sched/core.c:2692 [< inline >] ? finish_lock_switch kernel/kernel/sched/sched.h:1099 [] ? finish_task_switch+0x120/0x5f0 kernel/kernel/sched/core.c:2678 [< inline >] ? context_switch kernel/kernel/sched/core.c:2807 [] ? __schedule+0x919/0x1bd0 kernel/kernel/sched/core.c:3283 [] 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 [] syscall_return_slowpath+0x19f/0x210 kernel/arch/x86/entry/common.c:344 [] 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 Signed-off-by: Guillaume Nault Reviewed-by: Cyrill Gorcunov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ppp: ensure file->private_data can't be overridden

2016-04-20T06:42:04+00:00

[ Upstream commit e8e56ffd9d2973398b60ece1f1bebb8d67b4d032 ] Locking ppp_mutex must be done before dereferencing file->private_data, otherwise it could be modified before ppp_unattached_ioctl() takes the lock. This could lead ppp_unattached_ioctl() to override ->private_data, thus leaking reference to the ppp_file previously pointed to. v2: lock all ppp_ioctl() instead of just checking private_data in ppp_unattached_ioctl(), to avoid ambiguous behaviour. Fixes: f3ff8a4d80e8 ("ppp: push BKL down into the driver") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ppp: release rtnl mutex when interface creation fails

2016-04-20T06:42:00+00:00

[ Upstream commit 6faac63a6986f29ef39827f460edd3a5ba64ad5c ] Add missing rtnl_unlock() in the error path of ppp_create_interface(). Fixes: 58a89ecaca53 ("ppp: fix lockdep splat in ppp_dev_uninit()") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ppp, slip: Validate VJ compression slot parameters completely

2015-11-02T21:25:00+00:00

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 References: http://article.gmane.org/gmane.comp.security.oss.general/17908 Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller

ppp: fix lockdep splat in ppp_dev_uninit()

2015-09-25T19:38:11+00:00

ppp_dev_uninit() locks all_ppp_mutex while under rtnl mutex protection. ppp_create_interface() must then lock these mutexes in that same order to avoid possible deadlock. [ 120.880011] ====================================================== [ 120.880011] [ INFO: possible circular locking dependency detected ] [ 120.880011] 4.2.0 #1 Not tainted [ 120.880011] ------------------------------------------------------- [ 120.880011] ppp-apitest/15827 is trying to acquire lock: [ 120.880011] (&pn->all_ppp_mutex){+.+.+.}, at: [] ppp_dev_uninit+0x64/0xb0 [ppp_generic] [ 120.880011] [ 120.880011] but task is already holding lock: [ 120.880011] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x14 [ 120.880011] [ 120.880011] which lock already depends on the new lock. [ 120.880011] [ 120.880011] [ 120.880011] the existing dependency chain (in reverse order) is: [ 120.880011] [ 120.880011] -> #1 (rtnl_mutex){+.+.+.}: [ 120.880011] [] lock_acquire+0xcf/0x10e [ 120.880011] [] mutex_lock_nested+0x56/0x341 [ 120.880011] [] rtnl_lock+0x12/0x14 [ 120.880011] [] register_netdev+0x11/0x27 [ 120.880011] [] ppp_ioctl+0x289/0xc98 [ppp_generic] [ 120.880011] [] do_vfs_ioctl+0x4ea/0x532 [ 120.880011] [] SyS_ioctl+0x4e/0x7d [ 120.880011] [] entry_SYSCALL_64_fastpath+0x12/0x6f [ 120.880011] [ 120.880011] -> #0 (&pn->all_ppp_mutex){+.+.+.}: [ 120.880011] [] __lock_acquire+0xb07/0xe76 [ 120.880011] [] lock_acquire+0xcf/0x10e [ 120.880011] [] mutex_lock_nested+0x56/0x341 [ 120.880011] [] ppp_dev_uninit+0x64/0xb0 [ppp_generic] [ 120.880011] [] rollback_registered_many+0x19e/0x252 [ 120.880011] [] rollback_registered+0x29/0x38 [ 120.880011] [] unregister_netdevice_queue+0x6a/0x77 [ 120.880011] [] ppp_release+0x42/0x79 [ppp_generic] [ 120.880011] [] __fput+0xec/0x192 [ 120.880011] [] ____fput+0x9/0xb [ 120.880011] [] task_work_run+0x66/0x80 [ 120.880011] [] prepare_exit_to_usermode+0x8c/0xa7 [ 120.880011] [] syscall_return_slowpath+0xe4/0x104 [ 120.880011] [] int_ret_from_sys_call+0x25/0x9f [ 120.880011] [ 120.880011] other info that might help us debug this: [ 120.880011] [ 120.880011] Possible unsafe locking scenario: [ 120.880011] [ 120.880011] CPU0 CPU1 [ 120.880011] ---- ---- [ 120.880011] lock(rtnl_mutex); [ 120.880011] lock(&pn->all_ppp_mutex); [ 120.880011] lock(rtnl_mutex); [ 120.880011] lock(&pn->all_ppp_mutex); [ 120.880011] [ 120.880011] *** DEADLOCK *** Fixes: 8cb775bc0a34 ("ppp: fix device unregistration upon netns deletion") Reported-by: Sedat Dilek Tested-by: Sedat Dilek Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller

ppp: implement x-netns support

2015-08-25T21:11:20+00:00

Let packets move from one netns to the other at PPP encapsulation and decapsulation time. PPP units and channels remain in the netns in which they were originally created. Only the net_device may move to a different namespace. Cross netns handling is thus transparent to lower PPP layers (PPPoE, L2TP, etc.). PPP devices are automatically unregistered when their netns gets removed. So read() and poll() on the unit file descriptor will respectively receive EOF and POLLHUP. Channels aren't affected. Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller

ppp: fix device unregistration upon netns deletion

2015-08-17T19:22:20+00:00

PPP devices may get automatically unregistered when their network namespace is getting removed. This happens if the ppp control plane daemon (e.g. pppd) exits while it is the last user of this namespace. This leads to several races: * ppp_exit_net() may destroy the per namespace idr (pn->units_idr) before all file descriptors were released. Successive ppp_release() calls may then cleanup PPP devices with ppp_shutdown_interface() and try to use the already destroyed idr. * Automatic device unregistration may also happen before the ppp_release() call for that device gets executed. Once called on the file owning the device, ppp_release() will then clean it up and try to unregister it a second time. To fix these issues, operations defined in ppp_shutdown_interface() are moved to the PPP device's ndo_uninit() callback. This allows PPP devices to be properly cleaned up by unregister_netdev() and friends. So checking for ppp->owner is now an accurate test to decide if a PPP device should be unregistered. Setting ppp->owner is done in ppp_create_interface(), before device registration, in order to avoid unprotected modification of this field. Finally, ppp_exit_net() now starts by unregistering all remaining PPP devices to ensure that none will get unregistered after the call to idr_destroy(). Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller

ppp: call skb_checksum_complete_unset in ppp_receive_frame

2015-04-21T01:57:26+00:00

Call checksum_complete_unset in PPP receive to discard checksum-complete value. PPP does not pull checksum for headers and also modifies packet as in VJ compression. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

ppp_read(): switch to skb_copy_datagram_iter()

2014-12-09T21:29:10+00:00

Signed-off-by: Al Viro

net: ppp: Don't call bpf_prog_create() in ppp_lock

2014-11-11T20:15:03+00:00

In ppp_ioctl(), bpf_prog_create() is called inside ppp_lock, which eventually calls vmalloc() and hits BUG_ON() in vmalloc.c. This patch works around the problem by moving the allocation outside the lock. The bug was revealed by the recent change in net/core/filter.c, as it allocates via vmalloc() instead of kmalloc() now. Reported-and-tested-by: Stefan Seyfried Signed-off-by: Takashi Iwai Signed-off-by: David S. Miller