diff options
| author | Ido Schimmel <idosch@nvidia.com> | 2022-09-14 10:53:38 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-09-20 08:22:15 -0700 |
| commit | b07a9b26e2b1aa3711fd6935eccb08a463b1fb11 (patch) | |
| tree | b764464adf12f6c47dc4c98d8142c080dfa96471 /net/ipv6/ip6mr.c | |
| parent | cf412ec333250cb82bafe57169204e14a9f1c2ac (diff) | |
| download | lwn-b07a9b26e2b1aa3711fd6935eccb08a463b1fb11.tar.gz lwn-b07a9b26e2b1aa3711fd6935eccb08a463b1fb11.zip | |
ipmr: Always call ip{,6}_mr_forward() from RCU read-side critical section
These functions expect to be called from RCU read-side critical section,
but this only happens when invoked from the data path via
ip{,6}_mr_input(). They can also be invoked from process context in
response to user space adding a multicast route which resolves a cache
entry with queued packets [1][2].
Fix by adding missing rcu_read_lock() / rcu_read_unlock() in these call
paths.
[1]
WARNING: suspicious RCU usage
6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted
-----------------------------
net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by smcrouted/246:
#0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x11c/0x1420
stack backtrace:
CPU: 0 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x91/0xb9
vif_dev_read+0xbf/0xd0
ipmr_queue_xmit+0x135/0x1ab0
ip_mr_forward+0xe7b/0x13d0
ipmr_mfc_add+0x1a06/0x2ad0
ip_mroute_setsockopt+0x5c1/0x1420
do_ip_setsockopt+0x23d/0x37f0
ip_setsockopt+0x56/0x80
raw_setsockopt+0x219/0x290
__sys_setsockopt+0x236/0x4d0
__x64_sys_setsockopt+0xbe/0x160
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
[2]
WARNING: suspicious RCU usage
6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted
-----------------------------
net/ipv6/ip6mr.c:69 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by smcrouted/246:
#0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip6_mroute_setsockopt+0x6b9/0x2630
stack backtrace:
CPU: 1 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x91/0xb9
vif_dev_read+0xbf/0xd0
ip6mr_forward2.isra.0+0xc9/0x1160
ip6_mr_forward+0xef0/0x13f0
ip6mr_mfc_add+0x1ff2/0x31f0
ip6_mroute_setsockopt+0x1825/0x2630
do_ipv6_setsockopt+0x462/0x4440
ipv6_setsockopt+0x105/0x140
rawv6_setsockopt+0xd8/0x690
__sys_setsockopt+0x236/0x4d0
__x64_sys_setsockopt+0xbe/0x160
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv6/ip6mr.c')
| -rw-r--r-- | net/ipv6/ip6mr.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index a9ba41648e36..858fd8a28b5b 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1028,8 +1028,11 @@ static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt, ((struct nlmsgerr *)nlmsg_data(nlh))->error = -EMSGSIZE; } rtnl_unicast(skb, net, NETLINK_CB(skb).portid); - } else + } else { + rcu_read_lock(); ip6_mr_forward(net, mrt, skb->dev, skb, c); + rcu_read_unlock(); + } } } |