From: Jeongjun Park <aha310510@gmail.com>
To: davem@davemloft.net
Cc: edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
linux-kernel@vger.kernel.org, linux-ppp@vger.kernel.org,
netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com,
syzbot+393d0ef63475d9bb1f16@syzkaller.appspotmail.com,
Jeongjun Park <aha310510@gmail.com>
Subject: [PATCH] ppp: Fix deadlock caused by unsafe-irq lock in ap_get()
Date: Fri, 19 Apr 2024 02:59:10 +0900 [thread overview]
Message-ID: <20240418175910.7641-1-aha310510@gmail.com> (raw)
read_lock() present in ap_get() is interrupt-vulnerable, so the function needs to be modified.
Reported-by: syzbot+393d0ef63475d9bb1f16@syzkaller.appspotmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
---
drivers/net/ppp/ppp_async.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ppp/ppp_async.c b/drivers/net/ppp/ppp_async.c
index c33c3db3cc08..dc1d4633428a 100644
--- a/drivers/net/ppp/ppp_async.c
+++ b/drivers/net/ppp/ppp_async.c
@@ -133,12 +133,13 @@ static DEFINE_RWLOCK(disc_data_lock);
static struct asyncppp *ap_get(struct tty_struct *tty)
{
struct asyncppp *ap;
+ unsigned long flags;
- read_lock(&disc_data_lock);
+ flags = read_lock_irqsave(&disc_data_lock);
ap = tty->disc_data;
if (ap != NULL)
refcount_inc(&ap->refcnt);
- read_unlock(&disc_data_lock);
+ read_unlock_irqrestore(&disc_data_lock, flags);
return ap;
}
--
2.34.1
reply other threads:[~2024-04-18 17:59 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20240418175910.7641-1-aha310510@gmail.com \
--to=aha310510@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-ppp@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=syzbot+393d0ef63475d9bb1f16@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.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;
as well as URLs for NNTP newsgroup(s).