With latest sync from net-next tree, bpf-next has a bpf selftest failure:
[root@arch-fb-vm1 bpf]# ./test_progs -t setget_sockopt
...
[ 76.194349] ============================================
[ 76.194682] WARNING: possible recursive locking detected
[ 76.195039] 6.6.0-rc7-g37884503df08-dirty #67 Tainted: G W OE
[ 76.195518] --------------------------------------------
[ 76.195852] new_name/154 is trying to acquire lock:
[ 76.196159] ffff8c3e06ad8d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: ip_sock_set_tos+0x19/0x30
[ 76.196669]
[ 76.196669] but task is already holding lock:
[ 76.197028] ffff8c3e06ad8d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_listen+0x21/0x70
[ 76.197517]
[ 76.197517] other info that might help us debug this:
[ 76.197919] Possible unsafe locking scenario:
[ 76.197919]
[ 76.198287] CPU0
[ 76.198444] ----
[ 76.198600] lock(sk_lock-AF_INET);
[ 76.198831] lock(sk_lock-AF_INET);
[ 76.199062]
[ 76.199062] *** DEADLOCK ***
[ 76.199062]
[ 76.199420] May be due to missing lock nesting notation
[ 76.199420]
[ 76.199879] 2 locks held by new_name/154:
[ 76.200131] #0: ffff8c3e06ad8d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_listen+0x21/0x70
[ 76.200644] #1: ffffffff90f96a40 (rcu_read_lock){....}-{1:2}, at: __cgroup_bpf_run_filter_sock_ops+0x55/0x290
[ 76.201268]
[ 76.201268] stack backtrace:
[ 76.201538] CPU: 4 PID: 154 Comm: new_name Tainted: G W OE 6.6.0-rc7-g37884503df08-dirty #67
[ 76.202134] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[ 76.202699] Call Trace:
[ 76.202858] <TASK>
[ 76.203002] dump_stack_lvl+0x4b/0x80
[ 76.203239] __lock_acquire+0x740/0x1ec0
[ 76.203503] lock_acquire+0xc1/0x2a0
[ 76.203766] ? ip_sock_set_tos+0x19/0x30
[ 76.204050] ? sk_stream_write_space+0x12a/0x230
[ 76.204389] ? lock_release+0xbe/0x260
[ 76.204661] lock_sock_nested+0x32/0x80
[ 76.204942] ? ip_sock_set_tos+0x19/0x30
[ 76.205208] ip_sock_set_tos+0x19/0x30
[ 76.205452] do_ip_setsockopt+0x4b3/0x1580
[ 76.205719] __bpf_setsockopt+0x62/0xa0
[ 76.205963] bpf_sock_ops_setsockopt+0x11/0x20
[ 76.206247] bpf_prog_630217292049c96e_bpf_test_sockopt_int+0xbc/0x123
[ 76.206660] bpf_prog_493685a3bae00bbd_bpf_test_ip_sockopt+0x49/0x4b
[ 76.207055] bpf_prog_b0bcd27f269aeea0_skops_sockopt+0x44c/0xec7
[ 76.207437] __cgroup_bpf_run_filter_sock_ops+0xda/0x290
[ 76.207829] __inet_listen_sk+0x108/0x1b0
[ 76.208122] inet_listen+0x48/0x70
[ 76.208373] __sys_listen+0x74/0xb0
[ 76.208630] __x64_sys_listen+0x16/0x20
[ 76.208911] do_syscall_64+0x3f/0x90
[ 76.209174] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
...
Both ip_sock_set_tos() and inet_listen() calls lock_sock(sk) which
caused a dead lock.
To fix the issue, use sockopt_lock_sock() in ip_sock_set_tos()
instead. sockopt_lock_sock() will avoid lock_sock() if it is in bpf
context.
Fixes: 878d951c6712 ("inet: lock the socket in ip_sock_set_tos()")
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Suggested-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
net/ipv4/ip_sockglue.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 9c68b6b74d9f..2efc53526a38 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -602,9 +602,9 @@ void __ip_sock_set_tos(struct sock *sk, int val)
void ip_sock_set_tos(struct sock *sk, int val)
{
- lock_sock(sk);
+ sockopt_lock_sock(sk);
__ip_sock_set_tos(sk, val);
- release_sock(sk);
+ sockopt_release_sock(sk);
}
EXPORT_SYMBOL(ip_sock_set_tos);
--
2.34.1
