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| author | Jiayuan Chen <jiayuan.chen@linux.dev> | 2026-09-10 19:27:28 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-10 16:58:40 -0700 |
| commit | eaab8cab451b9502ce224cd202550375b894a467 (patch) | |
| tree | 08ad70b47d8493fbf286383f7659fa68d060fe47 | |
| parent | 01b245ba016d44861690594e10f67e026ce8552f (diff) | |
| download | linux-next-eaab8cab451b9502ce224cd202550375b894a467.tar.gz linux-next-eaab8cab451b9502ce224cd202550375b894a467.zip | |
tcp: Skip cond_resched() in inet_csk_listen_stop() under BPF context
bpf_sock_destroy() runs from the tcp iterator, under rcu_read_lock(). If
the sock is a listener that still has children in its accept queue,
tcp_abort() ends up in inet_csk_listen_stop() and the cond_resched()
there trips the debug check:
BUG: sleeping function called from invalid context at net/ipv4/inet_connection_sock.c:1523
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 628, name: test_progs
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
locks held by test_progs/628: 3, last CPU#3:
#0: ffff8881158cee18 (&p->lock){+.+.}-{4:4}, at: bpf_seq_read+0x56/0x1210
#1: ffff8881106bb858 (sk_lock-AF_INET6){+.+.}-{0:0}, at: bpf_iter_tcp_seq_show+0x32b/0x4b0
#2: ffffffffb435af20 (rcu_read_lock){....}-{1:3}, at: bpf_iter_run_prog+0x46b/0xde0
CPU: 3 UID: 0 PID: 628 Comm: test_progs Tainted: G W 7.2.0+ #65 PREEMPT
Tainted: [W]=WARN
Call Trace:
<TASK>
dump_stack_lvl+0xc1/0xf0
dump_stack+0x10/0x20
__might_resched+0x3d2/0x610
inet_csk_listen_stop+0x7b/0xbf0
tcp_abort+0x23b/0x3b0
bpf_sock_destroy+0xfc/0x140
bpf_prog_448133d24601754f_iter_tcp6_server+0x81/0x8a
bpf_iter_run_prog+0x538/0xde0
bpf_iter_tcp_seq_show+0x26b/0x4b0
bpf_seq_read+0x424/0x1210
vfs_read+0x197/0xe40
ksys_read+0x119/0x240
__x64_sys_read+0x72/0xc0
x64_sys_call+0x647/0x27e0
do_syscall_64+0xe5/0x610
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fad39b28aca
RSP: 002b:00007ffc381c61c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007ffc381c6a88 RCX: 00007fad39b28aca
RDX: 0000000000000032 RSI: 00007ffc381c6250 RDI: 0000000000000014
RBP: 00007ffc381c61e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 000055f077c1bbb0 R15: 00007fad3a0f3000
</TASK>
The commit that added the kfunc already guards lock_sock() in tcp_abort()
and udp_abort() with has_current_bpf_ctx(), but missed the listener path.
Do the same for the cond_resched(). The loop runs inside the iterator's
rcu_read_lock(), it must not reschedule or report a quiescent state there.
Fixes: 4ddbcb886268 ("bpf: Add bpf_sock_destroy kfunc")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260910112736.153710-1-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 6257459bcee2..6a30f1138454 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -1520,7 +1520,8 @@ skip_child_forget: local_bh_enable(); sock_put(child); - cond_resched(); + if (!has_current_bpf_ctx()) + cond_resched(); } if (queue->fastopenq.rskq_rst_head) { /* Free all the reqs queued in rskq_rst_head. */ |