| Message ID | 20231027182424.1444845-1-yonghong.song@linux.dev (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 06497763c8f15d08c0e356e651a61f2930a8987c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos() | expand |
On Fri, Oct 27, 2023 at 8:24 PM Yonghong Song <yonghong.song@linux.dev> wrote: > > 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] ============================================ > ... > > 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@google.com> > Suggested-by: Martin KaFai Lau <martin.lau@kernel.org> > Signed-off-by: Yonghong Song <yonghong.song@linux.dev> > --- SGTM, thanks. Reviewed-by: Eric Dumazet <edumazet@google.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Fri, 27 Oct 2023 11:24:24 -0700 you wrote: > 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 > ... > > [...] Here is the summary with links: - [net-next] net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos() https://git.kernel.org/netdev/net-next/c/06497763c8f1 You are awesome, thank you!
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);
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@google.com> Suggested-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> --- net/ipv4/ip_sockglue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)