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From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	 Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, Simon Horman <horms@kernel.org>,
	eric.dumazet@gmail.com,  Eric Dumazet <edumazet@google.com>,
	syzbot+ea40e4294e58b0292f74@syzkaller.appspotmail.com,
	 Jiri Pirko <jiri@nvidia.com>
Subject: [PATCH net] netdevsim: prevent bad user input in nsim_dev_health_break_write()
Date: Fri, 13 Dec 2024 17:25:18 +0000	[thread overview]
Message-ID: <20241213172518.2415666-1-edumazet@google.com> (raw)

If either a zero count or a large one is provided, kernel can crash.

Fixes: 82c93a87bf8b ("netdevsim: implement couple of testing devlink health reporters")
Reported-by: syzbot+ea40e4294e58b0292f74@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/675c6862.050a0220.37aaf.00b1.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
---
 drivers/net/netdevsim/health.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/netdevsim/health.c b/drivers/net/netdevsim/health.c
index 70e8bdf34be900f744e821fb237641a27bb71a7b..688f05316b5e109fc84222476023f3f1f078cf28 100644
--- a/drivers/net/netdevsim/health.c
+++ b/drivers/net/netdevsim/health.c
@@ -149,6 +149,8 @@ static ssize_t nsim_dev_health_break_write(struct file *file,
 	char *break_msg;
 	int err;
 
+	if (count == 0 || count > PAGE_SIZE)
+		return -EINVAL;
 	break_msg = memdup_user_nul(data, count);
 	if (IS_ERR(break_msg))
 		return PTR_ERR(break_msg);
-- 
2.47.1.613.gc27f4b7a9f-goog


             reply	other threads:[~2024-12-13 17:25 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-13 17:25 Eric Dumazet [this message]
2024-12-13 17:49 ` [PATCH net] netdevsim: prevent bad user input in nsim_dev_health_break_write() Joe Damato
2024-12-15 21:30 ` patchwork-bot+netdevbpf

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