On Wed, 2024-03-27 at 09:43 -0700, Alexei Starovoitov wrote: > I ffwded bpf tree with the recent net fixes and caught this: > > [ 48.386337] WARNING: CPU: 32 PID: 3276 at net/mptcp/subflow.c:1430 > subflow_data_ready+0x147/0x1c0 > [ 48.392012] Modules linked in: dummy bpf_testmod(O) [last unloaded: > bpf_test_no_cfi(O)] > [ 48.396609] CPU: 32 PID: 3276 Comm: test_progs Tainted: G > O 6.8.0-12873-g2c43c33bfd23 #1014 > #[ 48.467143] Call Trace: > [ 48.469094] <TASK> > [ 48.472159] ? __warn+0x80/0x180 > [ 48.475019] ? subflow_data_ready+0x147/0x1c0 > [ 48.478068] ? report_bug+0x189/0x1c0 > [ 48.480725] ? handle_bug+0x36/0x70 > [ 48.483061] ? exc_invalid_op+0x13/0x60 > [ 48.485809] ? asm_exc_invalid_op+0x16/0x20 > [ 48.488754] ? subflow_data_ready+0x147/0x1c0 > [ 48.492159] mptcp_set_rcvlowat+0x79/0x1d0 > [ 48.495026] sk_setsockopt+0x6c0/0x1540 > > It doesn't reproduce all the time though. > Some race? > Known issue? It was not known to me. Looks like something related to not so recent changes (rcvlowat support). Definitely looks lie a race. If you could share more info about the running context and/or a full decoded splat it could help, thanks! Paolo
