diff options
| author | Pengcheng Yang <yangpc@wangsu.com> | 2022-11-29 18:40:38 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-12-01 01:07:21 +0100 |
| commit | 7a9841ca025275b5b0edfb0b618934abb6ceec15 (patch) | |
| tree | bf9465eb426de07a1d82b69d57108066335b9300 | |
| parent | c67cae551f0df80421b5703ee56ff5e2fe9c4de6 (diff) | |
bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data
In tcp_bpf_send_verdict() redirection, the eval variable is assigned to
__SK_REDIRECT after the apply_bytes data is sent, if msg has more_data,
sock_put() will be called multiple times.
We should reset the eval variable to __SK_NONE every time more_data
starts.
This causes:
IPv4: Attempt to release TCP socket in state 1 00000000b4c925d7
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 5 PID: 4482 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0x110
Modules linked in:
CPU: 5 PID: 4482 Comm: sockhash_bypass Kdump: loaded Not tainted 6.0.0 #1
Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014
Call Trace:
<TASK>
__tcp_transmit_skb+0xa1b/0xb90
? __alloc_skb+0x8c/0x1a0
? __kmalloc_node_track_caller+0x184/0x320
tcp_write_xmit+0x22a/0x1110
__tcp_push_pending_frames+0x32/0xf0
do_tcp_sendpages+0x62d/0x640
tcp_bpf_push+0xae/0x2c0
tcp_bpf_sendmsg_redir+0x260/0x410
? preempt_count_add+0x70/0xa0
tcp_bpf_send_verdict+0x386/0x4b0
tcp_bpf_sendmsg+0x21b/0x3b0
sock_sendmsg+0x58/0x70
__sys_sendto+0xfa/0x170
? xfd_validate_state+0x1d/0x80
? switch_fpu_return+0x59/0xe0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: cd9733f5d75c ("tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/1669718441-2654-2-git-send-email-yangpc@wangsu.com
| -rw-r--r-- | net/ipv4/tcp_bpf.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index cf9c3e8f7ccb..f3e868f4cd9e 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -279,7 +279,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, bool cork = false, enospc = sk_msg_full(msg); struct sock *sk_redir; u32 tosend, origsize, sent, delta = 0; - u32 eval = __SK_NONE; + u32 eval; int ret; more_data: @@ -310,6 +310,7 @@ more_data: tosend = msg->sg.size; if (psock->apply_bytes && psock->apply_bytes < tosend) tosend = psock->apply_bytes; + eval = __SK_NONE; switch (psock->eval) { case __SK_PASS: |