ef9a5a62c6
current switchdev drivers dont seem to support offloading fdb entries pointing to the bridge device which have fdb->dst not set to any port. This patch adds a NULL fdb->dst check in the switchdev notifier code. This patch fixes the below NULL ptr dereference: $bridge fdb add 00:02:00:00:00:33 dev br0 self [ 69.953374] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 69.954044] IP: br_switchdev_fdb_notify+0x29/0x80 [ 69.954044] PGD 66527067 [ 69.954044] P4D 66527067 [ 69.954044] PUD 7899c067 [ 69.954044] PMD 0 [ 69.954044] [ 69.954044] Oops: 0000 [#1] SMP [ 69.954044] Modules linked in: [ 69.954044] CPU: 1 PID: 3074 Comm: bridge Not tainted 4.13.0-rc6+ #1 [ 69.954044] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 69.954044] task: ffff88007b827140 task.stack: ffffc90001564000 [ 69.954044] RIP: 0010:br_switchdev_fdb_notify+0x29/0x80 [ 69.954044] RSP: 0018:ffffc90001567918 EFLAGS: 00010246 [ 69.954044] RAX: 0000000000000000 RBX: ffff8800795e0880 RCX: 00000000000000c0 [ 69.954044] RDX: ffffc90001567920 RSI: 000000000000001c RDI: ffff8800795d0600 [ 69.954044] RBP: ffffc90001567938 R08: ffff8800795d0600 R09: 0000000000000000 [ 69.954044] R10: ffffc90001567a88 R11: ffff88007b849400 R12: ffff8800795e0880 [ 69.954044] R13: ffff8800795d0600 R14: ffffffff81ef8880 R15: 000000000000001c [ 69.954044] FS: 00007f93d3085700(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 69.954044] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 69.954044] CR2: 0000000000000008 CR3: 0000000066551000 CR4: 00000000000006e0 [ 69.954044] Call Trace: [ 69.954044] fdb_notify+0x3f/0xf0 [ 69.954044] __br_fdb_add.isra.12+0x1a7/0x370 [ 69.954044] br_fdb_add+0x178/0x280 [ 69.954044] rtnl_fdb_add+0x10a/0x200 [ 69.954044] rtnetlink_rcv_msg+0x1b4/0x240 [ 69.954044] ? skb_free_head+0x21/0x40 [ 69.954044] ? rtnl_calcit.isra.18+0xf0/0xf0 [ 69.954044] netlink_rcv_skb+0xed/0x120 [ 69.954044] rtnetlink_rcv+0x15/0x20 [ 69.954044] netlink_unicast+0x180/0x200 [ 69.954044] netlink_sendmsg+0x291/0x370 [ 69.954044] ___sys_sendmsg+0x180/0x2e0 [ 69.954044] ? filemap_map_pages+0x2db/0x370 [ 69.954044] ? do_wp_page+0x11d/0x420 [ 69.954044] ? __handle_mm_fault+0x794/0xd80 [ 69.954044] ? vma_link+0xcb/0xd0 [ 69.954044] __sys_sendmsg+0x4c/0x90 [ 69.954044] SyS_sendmsg+0x12/0x20 [ 69.954044] do_syscall_64+0x63/0xe0 [ 69.954044] entry_SYSCALL64_slow_path+0x25/0x25 [ 69.954044] RIP: 0033:0x7f93d2bad690 [ 69.954044] RSP: 002b:00007ffc7217a638 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 69.954044] RAX: ffffffffffffffda RBX: 00007ffc72182eac RCX: 00007f93d2bad690 [ 69.954044] RDX: 0000000000000000 RSI: 00007ffc7217a670 RDI: 0000000000000003 [ 69.954044] RBP: 0000000059a1f7f8 R08: 0000000000000006 R09: 000000000000000a [ 69.954044] R10: 00007ffc7217a400 R11: 0000000000000246 R12: 00007ffc7217a670 [ 69.954044] R13: 00007ffc72182a98 R14: 00000000006114c0 R15: 00007ffc72182aa0 [ 69.954044] Code: 1f 00 66 66 66 66 90 55 48 89 e5 48 83 ec 20 f6 47 20 04 74 0a 83 fe 1c 74 09 83 fe 1d 74 2c c9 66 90 c3 48 8b 47 10 48 8d 55 e8 <48> 8b 70 08 0f b7 47 1e 48 83 c7 18 48 89 7d f0 bf 03 00 00 00 [ 69.954044] RIP: br_switchdev_fdb_notify+0x29/0x80 RSP: ffffc90001567918 [ 69.954044] CR2: 0000000000000008 [ 69.954044] ---[ end trace 03e9eec4a82c238b ]--- Fixes: 6b26b51b1d13 ("net: bridge: Add support for notifying devices about FDB add/del") Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.