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YueHaibing 33902b4a42 netdevsim: Fix error handling in nsim_fib_init and nsim_fib_exit
In nsim_fib_init(), if register_fib_notifier failed, nsim_fib_net_ops
should be unregistered before return.

In nsim_fib_exit(), unregister_fib_notifier should be called before
nsim_fib_net_ops be unregistered, otherwise may cause use-after-free:

BUG: KASAN: use-after-free in nsim_fib_event_nb+0x342/0x570 [netdevsim]
Read of size 8 at addr ffff8881daaf4388 by task kworker/0:3/3499

CPU: 0 PID: 3499 Comm: kworker/0:3 Not tainted 5.3.0-rc7+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work [ipv6]
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xa9/0x10e lib/dump_stack.c:113
 print_address_description+0x65/0x380 mm/kasan/report.c:351
 __kasan_report+0x149/0x18d mm/kasan/report.c:482
 kasan_report+0xe/0x20 mm/kasan/common.c:618
 nsim_fib_event_nb+0x342/0x570 [netdevsim]
 notifier_call_chain+0x52/0xf0 kernel/notifier.c:95
 __atomic_notifier_call_chain+0x78/0x140 kernel/notifier.c:185
 call_fib_notifiers+0x30/0x60 net/core/fib_notifier.c:30
 call_fib6_entry_notifiers+0xc1/0x100 [ipv6]
 fib6_add+0x92e/0x1b10 [ipv6]
 __ip6_ins_rt+0x40/0x60 [ipv6]
 ip6_ins_rt+0x84/0xb0 [ipv6]
 __ipv6_ifa_notify+0x4b6/0x550 [ipv6]
 ipv6_ifa_notify+0xa5/0x180 [ipv6]
 addrconf_dad_completed+0xca/0x640 [ipv6]
 addrconf_dad_work+0x296/0x960 [ipv6]
 process_one_work+0x5c0/0xc00 kernel/workqueue.c:2269
 worker_thread+0x5c/0x670 kernel/workqueue.c:2415
 kthread+0x1d7/0x200 kernel/kthread.c:255
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 3388:
 save_stack+0x19/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:493
 kmalloc include/linux/slab.h:557 [inline]
 kzalloc include/linux/slab.h:748 [inline]
 ops_init+0xa9/0x220 net/core/net_namespace.c:127
 __register_pernet_operations net/core/net_namespace.c:1135 [inline]
 register_pernet_operations+0x1d4/0x420 net/core/net_namespace.c:1212
 register_pernet_subsys+0x24/0x40 net/core/net_namespace.c:1253
 nsim_fib_init+0x12/0x70 [netdevsim]
 veth_get_link_ksettings+0x2b/0x50 [veth]
 do_one_initcall+0xd4/0x454 init/main.c:939
 do_init_module+0xe0/0x330 kernel/module.c:3490
 load_module+0x3c2f/0x4620 kernel/module.c:3841
 __do_sys_finit_module+0x163/0x190 kernel/module.c:3931
 do_syscall_64+0x72/0x2e0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3534:
 save_stack+0x19/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x130/0x180 mm/kasan/common.c:455
 slab_free_hook mm/slub.c:1423 [inline]
 slab_free_freelist_hook mm/slub.c:1474 [inline]
 slab_free mm/slub.c:3016 [inline]
 kfree+0xe9/0x2d0 mm/slub.c:3957
 ops_free net/core/net_namespace.c:151 [inline]
 ops_free_list.part.7+0x156/0x220 net/core/net_namespace.c:184
 ops_free_list net/core/net_namespace.c:182 [inline]
 __unregister_pernet_operations net/core/net_namespace.c:1165 [inline]
 unregister_pernet_operations+0x221/0x2a0 net/core/net_namespace.c:1224
 unregister_pernet_subsys+0x1d/0x30 net/core/net_namespace.c:1271
 nsim_fib_exit+0x11/0x20 [netdevsim]
 nsim_module_exit+0x16/0x21 [netdevsim]
 __do_sys_delete_module kernel/module.c:1015 [inline]
 __se_sys_delete_module kernel/module.c:958 [inline]
 __x64_sys_delete_module+0x244/0x330 kernel/module.c:958
 do_syscall_64+0x72/0x2e0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 59c84b9fcf ("netdevsim: Restore per-network namespace accounting for fib entries")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13 11:30:14 -07:00
arch Kbuild fixes for v5.4 2019-10-05 12:56:59 -07:00
block block: sed-opal: fix sparse warning: convert __be64 data 2019-10-03 14:21:32 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation net: update net_dim documentation after rename 2019-10-10 16:37:10 -07:00
drivers netdevsim: Fix error handling in nsim_fib_init and nsim_fib_exit 2019-10-13 11:30:14 -07:00
fs Merge branch 'readdir' (readdir speedup and sanity checking) 2019-10-05 12:03:27 -07:00
include tcp: annotate sk->sk_wmem_queued lockless reads 2019-10-13 10:13:08 -07:00
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mm Merge branch 'hugepage-fallbacks' (hugepatch patches from David Rientjes) 2019-09-28 14:26:47 -07:00
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scripts scripts/setlocalversion: clear local variable to make it work for sh 2019-10-05 15:29:49 +09:00
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virt KVM/arm fixes for 5.4, take #1 2019-10-03 12:08:50 +02:00
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Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
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MAINTAINERS kgdb patches for 5.4-rc2 2019-10-03 11:17:57 -07:00
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README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.