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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-11-19 04:49:14 +0300
committerJakub Kicinski <kuba@kernel.org>2022-11-23 07:15:37 +0300
commite0833d1fedb02f038b526ae7dde178a076f56545 (patch)
treec406d3d5a97f9c8e16accf04f4f8f167215cdf96 /net/ipv4/inet_hashtables.c
parent8c5dae4c1a49489499e6708c7dd284370ca36287 (diff)
downloadlinux-e0833d1fedb02f038b526ae7dde178a076f56545.tar.xz
dccp/tcp: Fixup bhash2 bucket when connect() fails.
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@googlegroups.com> Reported-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/inet_hashtables.c')
-rw-r--r--net/ipv4/inet_hashtables.c38
1 files changed, 34 insertions, 4 deletions
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 18ef370af113..3cec471a2cd2 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)
#endif
}
-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_bind_hashbucket *head, *head2;
@@ -883,7 +883,11 @@ 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;
}
@@ -892,8 +896,19 @@ 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 leave inconsistency in bhash2.
+ */
+ inet_put_port(sk);
+ inet_reset_saddr(sk);
+ }
+
return -ENOMEM;
+ }
bhash = inet_bhashfn(net, port, hinfo->bhash_size);
head = &hinfo->bhash[bhash];
@@ -909,7 +924,10 @@ 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(&head2->lock);
- inet_update_saddr(sk, saddr, family);
+ if (reset)
+ inet_reset_saddr(sk);
+ else
+ inet_update_saddr(sk, saddr, family);
head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
@@ -930,8 +948,20 @@ 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