Hi Kuniyuki Iwashima, If you consider bisect commit or some other info from below link is useful: "https://lore.kernel.org/lkml/Y2xyHM1fcCkh9AKU@xxxxxxxxxxxxxxxx/"; could you add one more Reported-by tag from me, if no, please ignore the email. Thanks! BR. On 2022-11-16 at 14:28:05 -0800, Kuniyuki Iwashima wrote: > If a socket bound to a wildcard address fails to connect(), we > only reset saddr and keep the port. Then, we have to fix up the > bhash2 bucket; otherwise, the bucket has an inconsistent address > in the list. > > Also, listen() for such a socket will fire the WARN_ON() in > inet_csk_get_port(). [0] > > Note that when a system runs out of memory, we give up fixing the > bucket and unlink sk from bhash and bhash2 by inet_put_port(). > > [0]: > WARNING: CPU: 0 PID: 207 at net/ipv4/inet_connection_sock.c:548 inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1)) > Modules linked in: > CPU: 0 PID: 207 Comm: bhash2_prev_rep Not tainted 6.1.0-rc3-00799-gc8421681c845 #63 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.amzn2022.0.1 04/01/2014 > RIP: 0010:inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1)) > Code: 74 a7 eb 93 48 8b 54 24 18 0f b7 cb 4c 89 e6 4c 89 ff e8 48 b2 ff ff 49 8b 87 18 04 00 00 e9 32 ff ff ff 0f 0b e9 34 ff ff ff <0f> 0b e9 42 ff ff ff 41 8b 7f 50 41 8b 4f 54 89 fe 81 f6 00 00 ff > RSP: 0018:ffffc900003d7e50 EFLAGS: 00010202 > RAX: ffff8881047fb500 RBX: 0000000000004e20 RCX: 0000000000000000 > RDX: 000000000000000a RSI: 00000000fffffe00 RDI: 00000000ffffffff > RBP: ffffffff8324dc00 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000001 R14: 0000000000004e20 R15: ffff8881054e1280 > FS: 00007f8ac04dc740(0000) GS:ffff88842fc00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020001540 CR3: 00000001055fa003 CR4: 0000000000770ef0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > PKRU: 55555554 > Call Trace: > <TASK> > inet_csk_listen_start (net/ipv4/inet_connection_sock.c:1205) > inet_listen (net/ipv4/af_inet.c:228) > __sys_listen (net/socket.c:1810) > __x64_sys_listen (net/socket.c:1819 net/socket.c:1817 net/socket.c:1817) > do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) > RIP: 0033:0x7f8ac051de5d > Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 93 af 1b 00 f7 d8 64 89 01 48 > RSP: 002b:00007ffc1c177248 EFLAGS: 00000206 ORIG_RAX: 0000000000000032 > RAX: ffffffffffffffda RBX: 0000000020001550 RCX: 00007f8ac051de5d > RDX: ffffffffffffff80 RSI: 0000000000000000 RDI: 0000000000000004 > RBP: 00007ffc1c177270 R08: 0000000000000018 R09: 0000000000000007 > R10: 0000000020001540 R11: 0000000000000206 R12: 00007ffc1c177388 > R13: 0000000000401169 R14: 0000000000403e18 R15: 00007f8ac0723000 > </TASK> > > Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") > Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> > Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> > --- > include/net/inet_hashtables.h | 1 + > net/dccp/ipv4.c | 3 +-- > net/dccp/ipv6.c | 3 +-- > net/dccp/proto.c | 3 +-- > net/ipv4/inet_hashtables.c | 38 +++++++++++++++++++++++++++++++---- > net/ipv4/tcp.c | 3 +-- > net/ipv4/tcp_ipv4.c | 3 +-- > net/ipv6/tcp_ipv6.c | 3 +-- > 8 files changed, 41 insertions(+), 16 deletions(-) > > diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h > index ba06e8b52264..69174093078f 100644 > --- a/include/net/inet_hashtables.h > +++ b/include/net/inet_hashtables.h > @@ -282,6 +282,7 @@ inet_bhash2_addr_any_hashbucket(const struct sock *sk, const struct net *net, in > * rcv_saddr field should already have been updated when this is called. > */ > int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family); > +void inet_bhash2_reset_saddr(struct sock *sk); > > void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, > struct inet_bind2_bucket *tb2, unsigned short port); > diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c > index 95e376e3b911..b780827f5e0a 100644 > --- a/net/dccp/ipv4.c > +++ b/net/dccp/ipv4.c > @@ -143,8 +143,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) > * This unhashes the socket and releases the local port, if necessary. > */ > dccp_set_state(sk, DCCP_CLOSED); > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > - inet_reset_saddr(sk); > + inet_bhash2_reset_saddr(sk); > ip_rt_put(rt); > sk->sk_route_caps = 0; > inet->inet_dport = 0; > diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c > index 94c101ed57a9..602f3432d80b 100644 > --- a/net/dccp/ipv6.c > +++ b/net/dccp/ipv6.c > @@ -970,8 +970,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, > > late_failure: > dccp_set_state(sk, DCCP_CLOSED); > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > - inet_reset_saddr(sk); > + inet_bhash2_reset_saddr(sk); > __sk_dst_reset(sk); > failure: > inet->inet_dport = 0; > diff --git a/net/dccp/proto.c b/net/dccp/proto.c > index c548ca3e9b0e..85e35c5e8890 100644 > --- a/net/dccp/proto.c > +++ b/net/dccp/proto.c > @@ -279,8 +279,7 @@ int dccp_disconnect(struct sock *sk, int flags) > > inet->inet_dport = 0; > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > - inet_reset_saddr(sk); > + inet_bhash2_reset_saddr(sk); > > sk->sk_shutdown = 0; > sock_reset_flag(sk, SOCK_DONE); > diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c > index dcb6bc918966..d24a04815f20 100644 > --- a/net/ipv4/inet_hashtables.c > +++ b/net/ipv4/inet_hashtables.c > @@ -871,7 +871,7 @@ static void inet_update_saddr(struct sock *sk, void *saddr, int family) > } > } > > -int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > +static int __inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family, bool reset) > { > struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk); > struct inet_bind2_bucket *tb2, *new_tb2; > @@ -882,7 +882,11 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > if (!inet_csk(sk)->icsk_bind2_hash) { > /* Not bind()ed before. */ > - inet_update_saddr(sk, saddr, family); > + if (reset) > + inet_reset_saddr(sk); > + else > + inet_update_saddr(sk, saddr, family); > + > return 0; > } > > @@ -891,8 +895,19 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > * allocation fails. > */ > new_tb2 = kmem_cache_alloc(hinfo->bind2_bucket_cachep, GFP_ATOMIC); > - if (!new_tb2) > + if (!new_tb2) { > + if (reset) { > + /* The (INADDR_ANY, port) bucket might have already been > + * freed, then we cannot fixup icsk_bind2_hash, so we give > + * up and unlink sk from bhash/bhash2 not to fire WARN_ON() > + * in inet_csk_get_port(). > + */ > + inet_put_port(sk); > + inet_reset_saddr(sk); > + } > + > return -ENOMEM; > + } > > /* Unlink first not to show the wrong address for other threads. */ > head2 = inet_bhashfn_portaddr(hinfo, sk, net, port); > @@ -902,7 +917,10 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep, inet_csk(sk)->icsk_bind2_hash); > spin_unlock_bh(&head2->lock); > > - inet_update_saddr(sk, saddr, family); > + if (reset) > + inet_reset_saddr(sk); > + else > + inet_update_saddr(sk, saddr, family); > > /* Update bhash2 bucket. */ > head2 = inet_bhashfn_portaddr(hinfo, sk, net, port); > @@ -922,8 +940,20 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > return 0; > } > + > +int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > +{ > + return __inet_bhash2_update_saddr(sk, saddr, family, false); > +} > EXPORT_SYMBOL_GPL(inet_bhash2_update_saddr); > > +void inet_bhash2_reset_saddr(struct sock *sk) > +{ > + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > + __inet_bhash2_update_saddr(sk, NULL, 0, true); > +} > +EXPORT_SYMBOL_GPL(inet_bhash2_reset_saddr); > + > /* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm > * Note that we use 32bit integers (vs RFC 'short integers') > * because 2^16 is not a multiple of num_ephemeral and this > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 54836a6b81d6..4f2205756cfe 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -3114,8 +3114,7 @@ int tcp_disconnect(struct sock *sk, int flags) > > inet->inet_dport = 0; > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > - inet_reset_saddr(sk); > + inet_bhash2_reset_saddr(sk); > > sk->sk_shutdown = 0; > sock_reset_flag(sk, SOCK_DONE); > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 23dd7e9df2d5..da46357f501b 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -331,8 +331,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) > * if necessary. > */ > tcp_set_state(sk, TCP_CLOSE); > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > - inet_reset_saddr(sk); > + inet_bhash2_reset_saddr(sk); > ip_rt_put(rt); > sk->sk_route_caps = 0; > inet->inet_dport = 0; > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c > index 2f3ca3190d26..f0548dbcabd2 100644 > --- a/net/ipv6/tcp_ipv6.c > +++ b/net/ipv6/tcp_ipv6.c > @@ -346,8 +346,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, > > late_failure: > tcp_set_state(sk, TCP_CLOSE); > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > - inet_reset_saddr(sk); > + inet_bhash2_reset_saddr(sk); > failure: > inet->inet_dport = 0; > sk->sk_route_caps = 0; > -- > 2.30.2 >
