diff options
author | Eric Dumazet <edumazet@google.com> | 2022-06-16 00:34:34 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-29 09:03:22 +0200 |
commit | ad10d61c55aaa6e4ce50099d2e85cde4b19f1ac8 (patch) | |
tree | d4d997ec1b2eedfd6407af8b64b98cc6d958589d /net/core | |
parent | f617cef465523e453ea3df4e87cb8e02c3efbace (diff) |
net: fix data-race in dev_isalive()
[ Upstream commit cc26c2661fefea215f41edb665193324a5f99021 ]
dev_isalive() is called under RTNL or dev_base_lock protection.
This means that changes to dev->reg_state should be done with both locks held.
syzbot reported:
BUG: KCSAN: data-race in register_netdevice / type_show
write to 0xffff888144ecf518 of 1 bytes by task 20886 on cpu 0:
register_netdevice+0xb9f/0xdf0 net/core/dev.c:10050
lapbeth_new_device drivers/net/wan/lapbether.c:414 [inline]
lapbeth_device_event+0x4a0/0x6c0 drivers/net/wan/lapbether.c:456
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0x53/0xb0 kernel/notifier.c:455
__dev_notify_flags+0x1d6/0x3a0
dev_change_flags+0xa2/0xc0 net/core/dev.c:8607
do_setlink+0x778/0x2230 net/core/rtnetlink.c:2780
__rtnl_newlink net/core/rtnetlink.c:3546 [inline]
rtnl_newlink+0x114c/0x16a0 net/core/rtnetlink.c:3593
rtnetlink_rcv_msg+0x811/0x8c0 net/core/rtnetlink.c:6089
netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2501
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6107
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x58a/0x660 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x661/0x750 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
__sys_sendto+0x21e/0x2c0 net/socket.c:2119
__do_sys_sendto net/socket.c:2131 [inline]
__se_sys_sendto net/socket.c:2127 [inline]
__x64_sys_sendto+0x74/0x90 net/socket.c:2127
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
read to 0xffff888144ecf518 of 1 bytes by task 20423 on cpu 1:
dev_isalive net/core/net-sysfs.c:38 [inline]
netdev_show net/core/net-sysfs.c:50 [inline]
type_show+0x24/0x90 net/core/net-sysfs.c:112
dev_attr_show+0x35/0x90 drivers/base/core.c:2095
sysfs_kf_seq_show+0x175/0x240 fs/sysfs/file.c:59
kernfs_seq_show+0x75/0x80 fs/kernfs/file.c:162
seq_read_iter+0x2c3/0x8e0 fs/seq_file.c:230
kernfs_fop_read_iter+0xd1/0x2f0 fs/kernfs/file.c:235
call_read_iter include/linux/fs.h:2052 [inline]
new_sync_read fs/read_write.c:401 [inline]
vfs_read+0x5a5/0x6a0 fs/read_write.c:482
ksys_read+0xe8/0x1a0 fs/read_write.c:620
__do_sys_read fs/read_write.c:630 [inline]
__se_sys_read fs/read_write.c:628 [inline]
__x64_sys_read+0x3e/0x50 fs/read_write.c:628
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
value changed: 0x00 -> 0x01
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20423 Comm: udevd Tainted: G W 5.19.0-rc2-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r-- | net/core/dev.c | 28 | ||||
-rw-r--r-- | net/core/net-sysfs.c | 1 |
2 files changed, 17 insertions, 12 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 860fc6a98373..6111506a4105 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -378,16 +378,18 @@ static void list_netdevice(struct net_device *dev) /* Device list removal * caller must respect a RCU grace period before freeing/reusing dev */ -static void unlist_netdevice(struct net_device *dev) +static void unlist_netdevice(struct net_device *dev, bool lock) { ASSERT_RTNL(); /* Unlink dev from the device chain */ - write_lock(&dev_base_lock); + if (lock) + write_lock(&dev_base_lock); list_del_rcu(&dev->dev_list); netdev_name_node_del(dev->name_node); hlist_del_rcu(&dev->index_hlist); - write_unlock(&dev_base_lock); + if (lock) + write_unlock(&dev_base_lock); dev_base_seq_inc(dev_net(dev)); } @@ -10319,11 +10321,11 @@ int register_netdevice(struct net_device *dev) goto err_uninit; ret = netdev_register_kobject(dev); - if (ret) { - dev->reg_state = NETREG_UNREGISTERED; + write_lock(&dev_base_lock); + dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED; + write_unlock(&dev_base_lock); + if (ret) goto err_uninit; - } - dev->reg_state = NETREG_REGISTERED; __netdev_update_features(dev); @@ -10483,8 +10485,6 @@ static void netdev_wait_allrefs(struct net_device *dev) unsigned long rebroadcast_time, warning_time; int wait = 0, refcnt; - linkwatch_forget_dev(dev); - rebroadcast_time = warning_time = jiffies; refcnt = netdev_refcnt_read(dev); @@ -10598,7 +10598,10 @@ void netdev_run_todo(void) continue; } + write_lock(&dev_base_lock); dev->reg_state = NETREG_UNREGISTERED; + write_unlock(&dev_base_lock); + linkwatch_forget_dev(dev); netdev_wait_allrefs(dev); @@ -11043,9 +11046,10 @@ void unregister_netdevice_many(struct list_head *head) list_for_each_entry(dev, head, unreg_list) { /* And unlink it from device chain. */ - unlist_netdevice(dev); - + write_lock(&dev_base_lock); + unlist_netdevice(dev, false); dev->reg_state = NETREG_UNREGISTERING; + write_unlock(&dev_base_lock); } flush_all_backlogs(); @@ -11190,7 +11194,7 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, dev_close(dev); /* And unlink it from device chain */ - unlist_netdevice(dev); + unlist_netdevice(dev, true); synchronize_net(); diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 9e5657f63245..e9ea0695efb4 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -32,6 +32,7 @@ static const char fmt_dec[] = "%d\n"; static const char fmt_ulong[] = "%lu\n"; static const char fmt_u64[] = "%llu\n"; +/* Caller holds RTNL or dev_base_lock */ static inline int dev_isalive(const struct net_device *dev) { return dev->reg_state <= NETREG_REGISTERED; |