From: Anna Schumaker <[email protected]>
Otherwise we run the risk of having the lower_xprt freed from underneath
us, causing an oops that looks like this:
[ 224.150698] BUG: kernel NULL pointer dereference, address: 0000000000000018
[ 224.150951] #PF: supervisor read access in kernel mode
[ 224.151117] #PF: error_code(0x0000) - not-present page
[ 224.151278] PGD 0 P4D 0
[ 224.151361] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 224.151499] CPU: 2 PID: 99 Comm: kworker/u10:6 Not tainted 6.6.0-rc3-g6465e260f487 #41264 a00b0960990fb7bc6d6a330ee03588b67f08a47b
[ 224.151977] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022
[ 224.152216] Workqueue: xprtiod xs_tcp_tls_setup_socket [sunrpc]
[ 224.152434] RIP: 0010:xs_tcp_tls_setup_socket+0x3cc/0x7e0 [sunrpc]
[ 224.152643] Code: 00 00 48 8b 7c 24 08 e9 f3 01 00 00 48 83 7b c0 00 0f 85 d2 01 00 00 49 8d 84 24 f8 05 00 00 48 89 44 24 10 48 8b 00 48 89 c5 <4c> 8b 68 18 66 41 83 3f 0a 75 71 45 31 ff 4c 89 ef 31 f6 e8 5c 76
[ 224.153246] RSP: 0018:ffffb00ec060fd18 EFLAGS: 00010246
[ 224.153427] RAX: 0000000000000000 RBX: ffff8c06c2e53e40 RCX: 0000000000000001
[ 224.153652] RDX: ffff8c073bca2408 RSI: 0000000000000282 RDI: ffff8c06c259ee00
[ 224.153868] RBP: 0000000000000000 R08: ffffffff9da55aa0 R09: 0000000000000001
[ 224.154084] R10: 00000034306c30f1 R11: 0000000000000002 R12: ffff8c06c2e51800
[ 224.154300] R13: ffff8c06c355d400 R14: 0000000004208160 R15: ffff8c06c2e53820
[ 224.154521] FS: 0000000000000000(0000) GS:ffff8c073bd00000(0000) knlGS:0000000000000000
[ 224.154763] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 224.154940] CR2: 0000000000000018 CR3: 0000000062c1e000 CR4: 0000000000750ee0
[ 224.155157] PKRU: 55555554
[ 224.155244] Call Trace:
[ 224.155325] <TASK>
[ 224.155395] ? __die_body+0x68/0xb0
[ 224.155507] ? page_fault_oops+0x34c/0x3a0
[ 224.155635] ? _raw_spin_unlock_irqrestore+0xe/0x40
[ 224.155793] ? exc_page_fault+0x7a/0x1b0
[ 224.155916] ? asm_exc_page_fault+0x26/0x30
[ 224.156047] ? xs_tcp_tls_setup_socket+0x3cc/0x7e0 [sunrpc ae3a15912ae37fd51dafbdbc2dbd069117f8f5c8]
[ 224.156367] ? xs_tcp_tls_setup_socket+0x2fe/0x7e0 [sunrpc ae3a15912ae37fd51dafbdbc2dbd069117f8f5c8]
[ 224.156697] ? __pfx_xs_tls_handshake_done+0x10/0x10 [sunrpc ae3a15912ae37fd51dafbdbc2dbd069117f8f5c8]
[ 224.157013] process_scheduled_works+0x24e/0x450
[ 224.157158] worker_thread+0x21c/0x2d0
[ 224.157275] ? __pfx_worker_thread+0x10/0x10
[ 224.157409] kthread+0xe8/0x110
[ 224.157510] ? __pfx_kthread+0x10/0x10
[ 224.157628] ret_from_fork+0x37/0x50
[ 224.157741] ? __pfx_kthread+0x10/0x10
[ 224.157859] ret_from_fork_asm+0x1b/0x30
[ 224.157983] </TASK>
Signed-off-by: Anna Schumaker <[email protected]>
---
net/sunrpc/xprtsock.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 71cd916e384f..a15bf2ede89b 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2672,6 +2672,10 @@ static void xs_tcp_tls_setup_socket(struct work_struct *work)
rcu_read_lock();
lower_xprt = rcu_dereference(lower_clnt->cl_xprt);
rcu_read_unlock();
+
+ if (wait_on_bit_lock(&lower_xprt->state, XPRT_LOCKED, TASK_KILLABLE))
+ goto out_unlock;
+
status = xs_tls_handshake_sync(lower_xprt, &upper_xprt->xprtsec);
if (status) {
trace_rpc_tls_not_started(upper_clnt, upper_xprt);
@@ -2681,6 +2685,7 @@ static void xs_tcp_tls_setup_socket(struct work_struct *work)
status = xs_tcp_tls_finish_connecting(lower_xprt, upper_transport);
if (status)
goto out_close;
+ xprt_release_write(lower_xprt, NULL);
trace_rpc_socket_connect(upper_xprt, upper_transport->sock, 0);
if (!xprt_test_and_set_connected(upper_xprt)) {
@@ -2702,6 +2707,7 @@ static void xs_tcp_tls_setup_socket(struct work_struct *work)
return;
out_close:
+ xprt_release_write(lower_xprt, NULL);
rpc_shutdown_client(lower_clnt);
/* xprt_force_disconnect() wakes tasks with a fixed tk_status code.
--
2.42.0