diff options
author | Eric Dumazet <edumazet@google.com> | 2022-02-14 22:15:53 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2022-02-15 17:35:18 +0300 |
commit | 9ceaf6f76b203682bb6100e14b3d7da4c0bedde8 (patch) | |
tree | 0bb1f96180bce1e4c8c5ae888e6fa88d940561e0 /drivers | |
parent | 07dd44852be89386ab12210df90a2d78779f3bff (diff) | |
download | linux-9ceaf6f76b203682bb6100e14b3d7da4c0bedde8.tar.xz |
bonding: fix data-races around agg_select_timer
syzbot reported that two threads might write over agg_select_timer
at the same time. Make agg_select_timer atomic to fix the races.
BUG: KCSAN: data-race in bond_3ad_initiate_agg_selection / bond_3ad_state_machine_handler
read to 0xffff8881242aea90 of 4 bytes by task 1846 on cpu 1:
bond_3ad_state_machine_handler+0x99/0x2810 drivers/net/bonding/bond_3ad.c:2317
process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
worker_thread+0x616/0xa70 kernel/workqueue.c:2454
kthread+0x1bf/0x1e0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30
write to 0xffff8881242aea90 of 4 bytes by task 25910 on cpu 0:
bond_3ad_initiate_agg_selection+0x18/0x30 drivers/net/bonding/bond_3ad.c:1998
bond_open+0x658/0x6f0 drivers/net/bonding/bond_main.c:3967
__dev_open+0x274/0x3a0 net/core/dev.c:1407
dev_open+0x54/0x190 net/core/dev.c:1443
bond_enslave+0xcef/0x3000 drivers/net/bonding/bond_main.c:1937
do_set_master net/core/rtnetlink.c:2532 [inline]
do_setlink+0x94f/0x2500 net/core/rtnetlink.c:2736
__rtnl_newlink net/core/rtnetlink.c:3414 [inline]
rtnl_newlink+0xfeb/0x13e0 net/core/rtnetlink.c:3529
rtnetlink_rcv_msg+0x745/0x7e0 net/core/rtnetlink.c:5594
netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmsg+0x195/0x230 net/socket.c:2496
__do_sys_sendmsg net/socket.c:2505 [inline]
__se_sys_sendmsg net/socket.c:2503 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x00000050 -> 0x0000004f
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25910 Comm: syz-executor.1 Tainted: G W 5.17.0-rc4-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>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/bonding/bond_3ad.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index 9fd1d6cba3cd..a86b1f71762e 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -225,7 +225,7 @@ static inline int __check_agg_selection_timer(struct port *port) if (bond == NULL) return 0; - return BOND_AD_INFO(bond).agg_select_timer ? 1 : 0; + return atomic_read(&BOND_AD_INFO(bond).agg_select_timer) ? 1 : 0; } /** @@ -1995,7 +1995,7 @@ static void ad_marker_response_received(struct bond_marker *marker, */ void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout) { - BOND_AD_INFO(bond).agg_select_timer = timeout; + atomic_set(&BOND_AD_INFO(bond).agg_select_timer, timeout); } /** @@ -2279,6 +2279,28 @@ void bond_3ad_update_ad_actor_settings(struct bonding *bond) } /** + * bond_agg_timer_advance - advance agg_select_timer + * @bond: bonding structure + * + * Return true when agg_select_timer reaches 0. + */ +static bool bond_agg_timer_advance(struct bonding *bond) +{ + int val, nval; + + while (1) { + val = atomic_read(&BOND_AD_INFO(bond).agg_select_timer); + if (!val) + return false; + nval = val - 1; + if (atomic_cmpxchg(&BOND_AD_INFO(bond).agg_select_timer, + val, nval) == val) + break; + } + return nval == 0; +} + +/** * bond_3ad_state_machine_handler - handle state machines timeout * @work: work context to fetch bonding struct to work on from * @@ -2313,9 +2335,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work) if (!bond_has_slaves(bond)) goto re_arm; - /* check if agg_select_timer timer after initialize is timed out */ - if (BOND_AD_INFO(bond).agg_select_timer && - !(--BOND_AD_INFO(bond).agg_select_timer)) { + if (bond_agg_timer_advance(bond)) { slave = bond_first_slave_rcu(bond); port = slave ? &(SLAVE_AD_INFO(slave)->port) : NULL; |