6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 66b60b0c8c4a163b022a9f0ad6769b0fd3dc662f ]
syzkaller reported a warning [0] in inet_csk_destroy_sock() with no repro.
WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
However, the syzkaller's log hinted that connect() failed just before the warning due to FAULT_INJECTION. [1]
When connect() is called for an unbound socket, we search for an available ephemeral port. If a bhash bucket exists for the port, we call __inet_check_established() or __inet6_check_established() to check if the bucket is reusable.
If reusable, we add the socket into ehash and set inet_sk(sk)->inet_num.
Later, we look up the corresponding bhash2 bucket and try to allocate it if it does not exist.
Although it rarely occurs in real use, if the allocation fails, we must revert the changes by check_established(). Otherwise, an unconnected socket could illegally occupy an ehash entry.
Note that we do not put tw back into ehash because sk might have already responded to a packet for tw and it would be better to free tw earlier under such memory presure.
[0]: WARNING: CPU: 0 PID: 350830 at net/ipv4/inet_connection_sock.c:1193 inet_csk_destroy_sock (net/ipv4/inet_connection_sock.c:1193) Modules linked in: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:inet_csk_destroy_sock (net/ipv4/inet_connection_sock.c:1193) Code: 41 5c 41 5d 41 5e e9 2d 4a 3d fd e8 28 4a 3d fd 48 89 ef e8 f0 cd 7d ff 5b 5d 41 5c 41 5d 41 5e e9 13 4a 3d fd e8 0e 4a 3d fd <0f> 0b e9 61 fe ff ff e8 02 4a 3d fd 4c 89 e7 be 03 00 00 00 e8 05 RSP: 0018:ffffc9000b21fd38 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000009e78 RCX: ffffffff840bae40 RDX: ffff88806e46c600 RSI: ffffffff840bb012 RDI: ffff88811755cca8 RBP: ffff88811755c880 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000009e78 R11: 0000000000000000 R12: ffff88811755c8e0 R13: ffff88811755c892 R14: ffff88811755c918 R15: 0000000000000000 FS: 00007f03e5243800(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32f21000 CR3: 0000000112ffe001 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> ? inet_csk_destroy_sock (net/ipv4/inet_connection_sock.c:1193) dccp_close (net/dccp/proto.c:1078) inet_release (net/ipv4/af_inet.c:434) __sock_release (net/socket.c:660) sock_close (net/socket.c:1423) __fput (fs/file_table.c:377) __fput_sync (fs/file_table.c:462) __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) RIP: 0033:0x7f03e53852bb Code: 03 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 43 c9 f5 ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 c9 f5 ff 8b 44 RSP: 002b:00000000005dfba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f03e53852bb RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000167c R10: 0000000008a79680 R11: 0000000000000293 R12: 00007f03e4e43000 R13: 00007f03e4e43170 R14: 00007f03e4e43178 R15: 00007f03e4e43170 </TASK>
[1]: FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 350833 Comm: syz-executor.1 Not tainted 6.7.0-12272-g2121c43f88f5 #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1)) should_fail_ex (lib/fault-inject.c:52 lib/fault-inject.c:153) should_failslab (mm/slub.c:3748) kmem_cache_alloc (mm/slub.c:3763 mm/slub.c:3842 mm/slub.c:3867) inet_bind2_bucket_create (net/ipv4/inet_hashtables.c:135) __inet_hash_connect (net/ipv4/inet_hashtables.c:1100) dccp_v4_connect (net/dccp/ipv4.c:116) __inet_stream_connect (net/ipv4/af_inet.c:676) inet_stream_connect (net/ipv4/af_inet.c:747) __sys_connect_file (net/socket.c:2048 (discriminator 2)) __sys_connect (net/socket.c:2065) __x64_sys_connect (net/socket.c:2072) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) RIP: 0033:0x7f03e5284e5d 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 73 9f 1b 00 f7 d8 64 89 01 48 RSP: 002b:00007f03e4641cc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007f03e5284e5d RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 000000000000000b R14: 00007f03e52e5530 R15: 0000000000000000 </TASK>
Reported-by: syzkaller syzkaller@googlegroups.com Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/inet_hashtables.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index a532f749e4778..9456bf9e2705b 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -1131,10 +1131,33 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, return 0;
error: + if (sk_hashed(sk)) { + spinlock_t *lock = inet_ehash_lockp(hinfo, sk->sk_hash); + + sock_prot_inuse_add(net, sk->sk_prot, -1); + + spin_lock(lock); + sk_nulls_del_node_init_rcu(sk); + spin_unlock(lock); + + sk->sk_hash = 0; + inet_sk(sk)->inet_sport = 0; + inet_sk(sk)->inet_num = 0; + + if (tw) + inet_twsk_bind_unhash(tw, hinfo); + } + spin_unlock(&head2->lock); if (tb_created) inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb); - spin_unlock_bh(&head->lock); + spin_unlock(&head->lock); + + if (tw) + inet_twsk_deschedule_put(tw); + + local_bh_enable(); + return -ENOMEM; }