Cong reported a warning when running ./test_sockmp: https://lore.kernel.org/bpf/aAmIi0vlycHtbXeb@pop-os.localdomain/T/#t
------------[ cut here ]------------ WARNING: CPU: 1 PID: 40 at net/ipv4/af_inet.c inet_sock_destruct+0x173/0x1d5 Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Workqueue: events sk_psock_destroy RIP: 0010:inet_sock_destruct+0x173/0x1d5 RSP: 0018:ffff8880085cfc18 EFLAGS: 00010202 RAX: 1ffff11003dbfc00 RBX: ffff88801edfe3e8 RCX: ffffffff822f5af4 RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88801edfe16c RBP: ffff88801edfe184 R08: ffffed1003dbfc31 R09: 0000000000000000 R10: ffffffff822f5ab7 R11: ffff88801edfe187 R12: ffff88801edfdec0 R13: ffff888020376ac0 R14: ffff888020376ac0 R15: ffff888020376a60 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556365155830 CR3: 000000001d6aa000 CR4: 0000000000350ef0 Call Trace: <TASK> __sk_destruct+0x46/0x222 sk_psock_destroy+0x22f/0x242 process_one_work+0x504/0x8a8 ? process_one_work+0x39d/0x8a8 ? __pfx_process_one_work+0x10/0x10 ? worker_thread+0x44/0x2ae ? __list_add_valid_or_report+0x83/0xea ? srso_return_thunk+0x5/0x5f ? __list_add+0x45/0x52 process_scheduled_works+0x73/0x82 worker_thread+0x1ce/0x2ae
When we specify apply_bytes, we divide the msg into multiple segments, each with a length of 'send', and every time we send this part of the data using tcp_bpf_sendmsg_redir(), we use sk_msg_return_zero() to uncharge the memory of the specified 'send' size.
However, if the first segment of data fails to send, for example, the peer's buffer is full, we need to release all of the msg. When releasing the msg, we haven't uncharged the memory of the subsequent segments.
This modification does not make significant logical changes, but only fills in the missing uncharge places.
This issue has existed all along, until it was exposed after we added the apply test in test_sockmap:
commit 3448ad23b34e ("selftests/bpf: Add apply_bytes test to test_txmsg_redir_wait_sndmem in test_sockmap")
Jiayuan Chen (2): ktls, sockmap: Fix missing uncharge operation selftests/bpf: Add test to cover sockmap with ktls
net/tls/tls_sw.c | 7 ++ .../selftests/bpf/prog_tests/sockmap_ktls.c | 76 +++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_ktls.c | 10 +++ 3 files changed, 93 insertions(+)