Wed, May 20, 2015 at 07:48:20AM CEST, simon.hor...@netronome.com wrote:
>rocker_port_fdb_flush() may be called be called with
>trans == SWITCHDEV_TRANS_PREPARE and then trans == SWITCHDEV_TRANS_COMMIT from
>switchdev_port_attr_set() via switchdev_port_obj_add().
>
>Adding the new entry to the FDB table when trans == SWITCHDEV_TRANS_PREPARE
>may result in a memory leak because when trans == SWITCHDEV_TRANS_PREPARE
>rocker_flow_tbl_bridge() will allocate memory when called via
>rocker_port_fdb_learn(). However, when trans == SWITCHDEV_TRANS_COMMIT
>the presence of the FDB entry in the FDB table causes
>rocker_port_fdb() to set the ROCKER_OP_FLAG_REFRESH flag which results
>in rocker_port_fdb_learn() skipping the call to rocker_flow_tbl_bridge()
>which would free the memory allocated by it when
>trans == SWITCHDEV_TRANS_PREPARE.
>
>ip link add br0 type bridge
>ip link set up dev eth0
>ip link set dev eth0 master br0
>bridge fdb add 52:54:00:12:35:08 dev eth0
>bridge fdb add 52:54:00:12:35:09 dev eth0
>[ 2.600730] ------------[ cut here ]------------
>[ 2.601002] kernel BUG at drivers/net/ethernet/rocker/rocker.c:4369!
>[ 2.601373] invalid opcode: 0000 [#1] SMP
>[ 2.601963] Modules linked in:
>[ 2.602355] CPU: 0 PID: 64 Comm: bridge Not tainted
>4.1.0-rc3-01048-g6d0f50c50211-dirty #1075
>[ 2.602721] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>rel-1.8.0-0-g4c59f5d-20150219_092859-nilsson.home.kraxel.org 04/01/2014
>[ 2.602721] task: ffff880019facef0 ti: ffff88001f96c000 task.ti:
>ffff88001f96c000
>[ 2.602721] RIP: 0010:[<ffffffff811f1470>] [<ffffffff811f1470>]
>rocker_port_obj_add+0x150/0x160
>[ 2.602721] RSP: 0018:ffff88001f96fa98 EFLAGS: 00000212
>[ 2.602721] RAX: ffff880019d4fa68 RBX: ffff88001f96fb18 RCX:
>0000000000000000
>[ 2.602721] RDX: ffff880019d4f000 RSI: ffff88001f96fb18 RDI:
>ffff880019d4f000
>[ 2.602721] RBP: 0000000000000001 R08: 0000000000000000 R09:
>ffff88001f904620
>[ 2.602721] R10: ffff88001f96fb60 R11: ffff880019e9d100 R12:
>ffff88001f96fb18
>[ 2.602721] R13: ffff880019d4f680 R14: ffff88001f904610 R15:
>ffff8800198f7b80
>[ 2.602721] FS: 00007f3eee917700(0000) GS:ffff88001b000000(0000)
>knlGS:0000000000000000
>[ 2.602721] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>[ 2.602721] CR2: 00007f3eee4a15cb CR3: 000000001f933000 CR4:
>00000000000006b0
>[ 2.602721] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
>0000000000000000
>[ 2.602721] DR3: 0000000000000000 DR6: 0000000000000000 DR7:
>0000000000000000
>[ 2.602721] Stack:
>[ 2.602721] 0000000000000000 ffff88001f96fb18 ffff880019d4f000
>ffff88001f96fb18
>[ 2.602721] ffff880019d4f000 ffffffff81332105 ffff88001f96fb50
>ffffffff814464c0
>[ 2.602721] ffff88001f96fb18 ffff88001f904600 ffff880019d4f000
>ffffffff813326e5
>[ 2.602721] Call Trace:
>[ 2.602721] [<ffffffff81332105>] ? __switchdev_port_obj_add+0x25/0x90
>[ 2.602721] [<ffffffff813326e5>] ? switchdev_port_obj_add+0x25/0xc0
>[ 2.602721] [<ffffffff813327b1>] ? switchdev_port_fdb_add+0x31/0x40
>[ 2.602721] [<ffffffff8123911f>] ? rtnl_fdb_add+0xff/0x1e0
>[ 2.602721] [<ffffffff81237d8e>] ? rtnetlink_rcv_msg+0x7e/0x250
>[ 2.602721] [<ffffffff8121d1ce>] ? __skb_recv_datagram+0xfe/0x4b0
>[ 2.602721] [<ffffffff81237d10>] ? rtnetlink_rcv+0x30/0x30
>[ 2.602721] [<ffffffff81247958>] ? netlink_rcv_skb+0xa8/0xd0
>[ 2.602721] [<ffffffff81237cff>] ? rtnetlink_rcv+0x1f/0x30
>[ 2.602721] [<ffffffff81247220>] ? netlink_unicast+0x150/0x200
>[ 2.602721] [<ffffffff81247714>] ? netlink_sendmsg+0x374/0x3e0
>[ 2.602721] [<ffffffff8120f8df>] ? sock_sendmsg+0xf/0x30
>[ 2.602721] [<ffffffff8120ffd3>] ? ___sys_sendmsg+0x1f3/0x200
>[ 2.602721] [<ffffffff812100e5>] ? ___sys_recvmsg+0x105/0x140
>[ 2.602721] [<ffffffff810a36f0>] ? SyS_readahead+0x90/0x90
>[ 2.602721] [<ffffffff81098dfd>] ? filemap_map_pages+0x1ed/0x210
>[ 2.602721] [<ffffffff810b77fc>] ? handle_mm_fault+0x5fc/0xe50
>[ 2.602721] [<ffffffff81210ef9>] ? __sys_sendmsg+0x39/0x70
>[ 2.602721] [<ffffffff8133ce17>] ? system_call_fastpath+0x12/0x6a
>[ 2.602721] Code: b7 8f a0 06 00 00 48 83 bf 88 06 00 00 00 74 1d 48 83 c4
>08 89 ee 4c 89 ef 5b 5d 41 5c 41 5d 0f b7 c9 45 31 c0 e9 51 db ff ff 90 <0f>
>0b b8 ea ff ff ff e9 cf fe ff ff 0f 1f 40 00 41 57 41 56 b9
>[ 2.602721] RIP [<ffffffff811f1470>] rocker_port_obj_add+0x150/0x160
>[ 2.602721] RSP <ffff88001f96fa98>
>[ 2.615848] ---[ end trace 4f7b4f1c98077108 ]---
>
>The above is resolved by not adding the new FDB entry to the FDB table
>if trans == SWITCHDEV_TRANS_PREPARE.
>
>For symmetry this patch also skips deleting FDB entries from the FDB
>table trans == SWITCHDEV_TRANS_PREPARE. However, my analysis is that
>this never occurs as trans is always SWITCHDEV_TRANS_NONE when removing
>FDB entries.
>
>Fixes: c4f20321d968 ("rocker: support prepare-commit transaction model")
>Acked-by: Scott Feldman <sfel...@gmail.com>
>Signed-off-by: Simon Horman <simon.hor...@netronome.com>
Acked-by: Jiri Pirko <j...@resnulli.us>
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