From: Pavel Skripkin <paskripkin@gmail.com>
To: marcel@holtmann.org, johan.hedberg@gmail.com,
luiz.dentz@gmail.com, lukas@wunner.de
Cc: linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
Pavel Skripkin <paskripkin@gmail.com>,
Yiru Xu <xyru1999@gmail.com>
Subject: [PATCH] Bluetooth: hci_serdev: call init_rwsem() before p->open()
Date: Thu, 13 Jan 2022 16:27:04 +0300 [thread overview]
Message-ID: <20220113132704.4354-1-paskripkin@gmail.com> (raw)
kvartet reported, that hci_uart_tx_wakeup() uses uninitialized rwsem.
The problem was in wrong place for percpu_init_rwsem() call.
hci_uart_proto::open() may register a timer whose callback may call
hci_uart_tx_wakeup(). There is a chance, that hci_uart_register_device()
thread won't be fast enough to call percpu_init_rwsem().
Fix it my moving percpu_init_rwsem() call before p->open().
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 2 PID: 18524 Comm: syz-executor.5 Not tainted 5.16.0-rc6 #9
...
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
assign_lock_key kernel/locking/lockdep.c:951 [inline]
register_lock_class+0x148d/0x1950 kernel/locking/lockdep.c:1263
__lock_acquire+0x106/0x57e0 kernel/locking/lockdep.c:4906
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5602
percpu_down_read_trylock include/linux/percpu-rwsem.h:92 [inline]
hci_uart_tx_wakeup+0x12e/0x490 drivers/bluetooth/hci_ldisc.c:124
h5_timed_event+0x32f/0x6a0 drivers/bluetooth/hci_h5.c:188
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
Fixes: d73e17281665 ("Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops")
Reported-by: Yiru Xu <xyru1999@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
drivers/bluetooth/hci_serdev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
index 9e03402ef1b3..e9a44ab3812d 100644
--- a/drivers/bluetooth/hci_serdev.c
+++ b/drivers/bluetooth/hci_serdev.c
@@ -305,6 +305,8 @@ int hci_uart_register_device(struct hci_uart *hu,
if (err)
return err;
+ percpu_init_rwsem(&hu->proto_lock);
+
err = p->open(hu);
if (err)
goto err_open;
@@ -327,7 +329,6 @@ int hci_uart_register_device(struct hci_uart *hu,
INIT_WORK(&hu->init_ready, hci_uart_init_work);
INIT_WORK(&hu->write_work, hci_uart_write_work);
- percpu_init_rwsem(&hu->proto_lock);
/* Only when vendor specific setup callback is provided, consider
* the manufacturer information valid. This avoids filling in the
--
2.34.1
next reply other threads:[~2022-01-13 13:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 13:27 Pavel Skripkin [this message]
2022-01-21 22:47 ` Marcel Holtmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220113132704.4354-1-paskripkin@gmail.com \
--to=paskripkin@gmail.com \
--cc=johan.hedberg@gmail.com \
--cc=linux-bluetooth@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luiz.dentz@gmail.com \
--cc=lukas@wunner.de \
--cc=marcel@holtmann.org \
--cc=xyru1999@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome