Commits
Roopa Prabhu committed ef9a5a62c63
bridge: check for null fdb->dst before notifying switchdev drivers
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>