33902b4a42
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: 59c84b9fcf42 ("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>
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.