From b5141915b5aec3b29a63db869229e3741ebce258 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 29 Jul 2020 11:34:36 +0300 Subject: vxlan: Ensure FDB dump is performed under RCU The commit cited below removed the RCU read-side critical section from rtnl_fdb_dump() which means that the ndo_fdb_dump() callback is invoked without RCU protection. This results in the following warning [1] in the VXLAN driver, which relied on the callback being invoked from an RCU read-side critical section. Fix this by calling rcu_read_lock() in the VXLAN driver, as already done in the bridge driver. [1] WARNING: suspicious RCU usage 5.8.0-rc4-custom-01521-g481007553ce6 #29 Not tainted ----------------------------- drivers/net/vxlan.c:1379 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by bridge/166: #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xea/0x1090 stack backtrace: CPU: 1 PID: 166 Comm: bridge Not tainted 5.8.0-rc4-custom-01521-g481007553ce6 #29 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x100/0x184 lockdep_rcu_suspicious+0x153/0x15d vxlan_fdb_dump+0x51e/0x6d0 rtnl_fdb_dump+0x4dc/0xad0 netlink_dump+0x540/0x1090 __netlink_dump_start+0x695/0x950 rtnetlink_rcv_msg+0x802/0xbd0 netlink_rcv_skb+0x17a/0x480 rtnetlink_rcv+0x22/0x30 netlink_unicast+0x5ae/0x890 netlink_sendmsg+0x98a/0xf40 __sys_sendto+0x279/0x3b0 __x64_sys_sendto+0xe6/0x1a0 do_syscall_64+0x54/0xa0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fe14fa2ade0 Code: Bad RIP value. RSP: 002b:00007fff75bb5b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00005614b1ba0020 RCX: 00007fe14fa2ade0 RDX: 000000000000011c RSI: 00007fff75bb5b90 RDI: 0000000000000003 RBP: 00007fff75bb5b90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00005614b1b89160 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Fixes: 5e6d24358799 ("bridge: netlink dump interface at par with brctl") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/net/vxlan.c') diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 89d85dcb200e..5efe1e28f270 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1376,6 +1376,7 @@ static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb, for (h = 0; h < FDB_HASH_SIZE; ++h) { struct vxlan_fdb *f; + rcu_read_lock(); hlist_for_each_entry_rcu(f, &vxlan->fdb_head[h], hlist) { struct vxlan_rdst *rd; @@ -1387,8 +1388,10 @@ static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb, cb->nlh->nlmsg_seq, RTM_NEWNEIGH, NLM_F_MULTI, NULL); - if (err < 0) + if (err < 0) { + rcu_read_unlock(); goto out; + } skip_nh: *idx += 1; continue; @@ -1403,12 +1406,15 @@ skip_nh: cb->nlh->nlmsg_seq, RTM_NEWNEIGH, NLM_F_MULTI, rd); - if (err < 0) + if (err < 0) { + rcu_read_unlock(); goto out; + } skip: *idx += 1; } } + rcu_read_unlock(); } out: return err; -- cgit v1.2.3 From fda2ec62cf1aa7cbee52289dc8059cd3662795da Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Sat, 1 Aug 2020 07:07:50 +0000 Subject: vxlan: fix memleak of fdb When vxlan interface is deleted, all fdbs are deleted by vxlan_flush(). vxlan_flush() flushes fdbs but it doesn't delete fdb, which contains all-zeros-mac because it is deleted by vxlan_uninit(). But vxlan_uninit() deletes only the fdb, which contains both all-zeros-mac and default vni. So, the fdb, which contains both all-zeros-mac and non-default vni will not be deleted. Test commands: ip link add vxlan0 type vxlan dstport 4789 external ip link set vxlan0 up bridge fdb add to 00:00:00:00:00:00 dst 172.0.0.1 dev vxlan0 via lo \ src_vni 10000 self permanent ip link del vxlan0 kmemleak reports as follows: unreferenced object 0xffff9486b25ced88 (size 96): comm "bridge", pid 2151, jiffies 4294701712 (age 35506.901s) hex dump (first 32 bytes): 02 00 00 00 ac 00 00 01 40 00 09 b1 86 94 ff ff ........@....... 46 02 00 00 00 00 00 00 a7 03 00 00 12 b5 6a 6b F.............jk backtrace: [<00000000c10cf651>] vxlan_fdb_append.part.51+0x3c/0xf0 [vxlan] [<000000006b31a8d9>] vxlan_fdb_create+0x184/0x1a0 [vxlan] [<0000000049399045>] vxlan_fdb_update+0x12f/0x220 [vxlan] [<0000000090b1ef00>] vxlan_fdb_add+0x12a/0x1b0 [vxlan] [<0000000056633c2c>] rtnl_fdb_add+0x187/0x270 [<00000000dd5dfb6b>] rtnetlink_rcv_msg+0x264/0x490 [<00000000fc44dd54>] netlink_rcv_skb+0x4a/0x110 [<00000000dff433e7>] netlink_unicast+0x18e/0x250 [<00000000b87fb421>] netlink_sendmsg+0x2e9/0x400 [<000000002ed55153>] ____sys_sendmsg+0x237/0x260 [<00000000faa51c66>] ___sys_sendmsg+0x88/0xd0 [<000000006c3982f1>] __sys_sendmsg+0x4e/0x80 [<00000000a8f875d2>] do_syscall_64+0x56/0xe0 [<000000003610eefa>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 unreferenced object 0xffff9486b1c40080 (size 128): comm "bridge", pid 2157, jiffies 4294701754 (age 35506.866s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 f8 dc 42 b2 86 94 ff ff ..........B..... 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace: [<00000000a2981b60>] vxlan_fdb_create+0x67/0x1a0 [vxlan] [<0000000049399045>] vxlan_fdb_update+0x12f/0x220 [vxlan] [<0000000090b1ef00>] vxlan_fdb_add+0x12a/0x1b0 [vxlan] [<0000000056633c2c>] rtnl_fdb_add+0x187/0x270 [<00000000dd5dfb6b>] rtnetlink_rcv_msg+0x264/0x490 [<00000000fc44dd54>] netlink_rcv_skb+0x4a/0x110 [<00000000dff433e7>] netlink_unicast+0x18e/0x250 [<00000000b87fb421>] netlink_sendmsg+0x2e9/0x400 [<000000002ed55153>] ____sys_sendmsg+0x237/0x260 [<00000000faa51c66>] ___sys_sendmsg+0x88/0xd0 [<000000006c3982f1>] __sys_sendmsg+0x4e/0x80 [<00000000a8f875d2>] do_syscall_64+0x56/0xe0 [<000000003610eefa>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 3ad7a4b141eb ("vxlan: support fdb and learning in COLLECT_METADATA mode") Signed-off-by: Taehee Yoo Acked-by: Roopa Prabhu Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/net/vxlan.c') diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 5efe1e28f270..a7c3939264b0 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -3076,8 +3076,10 @@ static void vxlan_flush(struct vxlan_dev *vxlan, bool do_all) if (!do_all && (f->state & (NUD_PERMANENT | NUD_NOARP))) continue; /* the all_zeros_mac entry is deleted at vxlan_uninit */ - if (!is_zero_ether_addr(f->eth_addr)) - vxlan_fdb_destroy(vxlan, f, true, true); + if (is_zero_ether_addr(f->eth_addr) && + f->vni == vxlan->cfg.vni) + continue; + vxlan_fdb_destroy(vxlan, f, true, true); } spin_unlock_bh(&vxlan->hash_lock[h]); } -- cgit v1.2.3