697cd36cda
When a bridge port is being deleted, do not dereference it later in br_vlan_port_event() as it can result in a use-after-free [1] if the RCU callback was executed before invoking the function. [1] [ 129.638551] ================================================================== [ 129.646904] BUG: KASAN: use-after-free in br_vlan_port_event+0x53c/0x5fd [ 129.654406] Read of size 8 at addr ffff8881e4aa1ae8 by task ip/483 [ 129.663008] CPU: 0 PID: 483 Comm: ip Not tainted 5.1.0-rc5-custom-02265-ga946bd73daac #1383 [ 129.672359] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016 [ 129.682484] Call Trace: [ 129.685242] dump_stack+0xa9/0x10e [ 129.689068] print_address_description.cold.2+0x9/0x25e [ 129.694930] kasan_report.cold.3+0x78/0x9d [ 129.704420] br_vlan_port_event+0x53c/0x5fd [ 129.728300] br_device_event+0x2c7/0x7a0 [ 129.741505] notifier_call_chain+0xb5/0x1c0 [ 129.746202] rollback_registered_many+0x895/0xe90 [ 129.793119] unregister_netdevice_many+0x48/0x210 [ 129.803384] rtnl_delete_link+0xe1/0x140 [ 129.815906] rtnl_dellink+0x2a3/0x820 [ 129.844166] rtnetlink_rcv_msg+0x397/0x910 [ 129.868517] netlink_rcv_skb+0x137/0x3a0 [ 129.882013] netlink_unicast+0x49b/0x660 [ 129.900019] netlink_sendmsg+0x755/0xc90 [ 129.915758] ___sys_sendmsg+0x761/0x8e0 [ 129.966315] __sys_sendmsg+0xf0/0x1c0 [ 129.988918] do_syscall_64+0xa4/0x470 [ 129.993032] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 129.998696] RIP: 0033:0x7ff578104b58 ... [ 130.073811] Allocated by task 479: [ 130.077633] __kasan_kmalloc.constprop.5+0xc1/0xd0 [ 130.083008] kmem_cache_alloc_trace+0x152/0x320 [ 130.088090] br_add_if+0x39c/0x1580 [ 130.092005] do_set_master+0x1aa/0x210 [ 130.096211] do_setlink+0x985/0x3100 [ 130.100224] __rtnl_newlink+0xc52/0x1380 [ 130.104625] rtnl_newlink+0x6b/0xa0 [ 130.108541] rtnetlink_rcv_msg+0x397/0x910 [ 130.113136] netlink_rcv_skb+0x137/0x3a0 [ 130.117538] netlink_unicast+0x49b/0x660 [ 130.121939] netlink_sendmsg+0x755/0xc90 [ 130.126340] ___sys_sendmsg+0x761/0x8e0 [ 130.130645] __sys_sendmsg+0xf0/0x1c0 [ 130.134753] do_syscall_64+0xa4/0x470 [ 130.138864] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 130.146195] Freed by task 0: [ 130.149421] __kasan_slab_free+0x125/0x170 [ 130.154016] kfree+0xf3/0x310 [ 130.157349] kobject_put+0x1a8/0x4c0 [ 130.161363] rcu_core+0x859/0x19b0 [ 130.165175] __do_softirq+0x250/0xa26 [ 130.170956] The buggy address belongs to the object at ffff8881e4aa1ae8 which belongs to the cache kmalloc-1k of size 1024 [ 130.184972] The buggy address is located 0 bytes inside of 1024-byte region [ffff8881e4aa1ae8, ffff8881e4aa1ee8) Fixes: 9c0ec2e7182a ("bridge: support binding vlan dev link state to vlan member bridge ports") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Cc: Mike Manning <mmanning@vyatta.att-mail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Mike Manning <mmanning@vyatta.att-mail.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.