From: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
To: davem@davemloft.net, kuba@kernel.org
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+c2a7e5c5211605a90865@syzkaller.appspotmail.com
Subject: [PATCH] net/qrtr: restrict user-controlled length in qrtr_tun_write_iter()
Date: Tue, 2 Feb 2021 15:20:59 +0600 [thread overview]
Message-ID: <20210202092059.1361381-1-snovitoll@gmail.com> (raw)
syzbot found WARNING in qrtr_tun_write_iter [1] when write_iter length
exceeds KMALLOC_MAX_SIZE causing order >= MAX_ORDER condition.
Additionally, there is no check for 0 length write.
[1]
WARNING: mm/page_alloc.c:5011
[..]
Call Trace:
alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267
alloc_pages include/linux/gfp.h:547 [inline]
kmalloc_order+0x2e/0xb0 mm/slab_common.c:837
kmalloc_order_trace+0x14/0x120 mm/slab_common.c:853
kmalloc include/linux/slab.h:557 [inline]
kzalloc include/linux/slab.h:682 [inline]
qrtr_tun_write_iter+0x8a/0x180 net/qrtr/tun.c:83
call_write_iter include/linux/fs.h:1901 [inline]
Reported-by: syzbot+c2a7e5c5211605a90865@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
---
net/qrtr/tun.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/qrtr/tun.c b/net/qrtr/tun.c
index 15ce9b642b25..b238c40a9984 100644
--- a/net/qrtr/tun.c
+++ b/net/qrtr/tun.c
@@ -80,6 +80,12 @@ static ssize_t qrtr_tun_write_iter(struct kiocb *iocb, struct iov_iter *from)
ssize_t ret;
void *kbuf;
+ if (!len)
+ return -EINVAL;
+
+ if (len > KMALLOC_MAX_SIZE)
+ return -ENOMEM;
+
kbuf = kzalloc(len, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
--
2.25.1
next reply other threads:[~2021-02-02 9:23 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 9:20 Sabyrzhan Tasbolatov [this message]
2021-02-04 0:28 ` [PATCH] net/qrtr: restrict user-controlled length in qrtr_tun_write_iter() Jakub Kicinski
2021-02-04 9:02 ` [PATCH] net/qrtr: replaced useless kzalloc with kmalloc " Sabyrzhan Tasbolatov
2021-02-04 18:51 ` Jakub Kicinski
2021-02-04 18:53 ` Jakub Kicinski
2021-02-04 0:40 ` [PATCH] net/qrtr: restrict user-controlled length " patchwork-bot+netdevbpf
2021-02-12 11:51 ` Eric Dumazet
2021-02-21 12:39 ` [PATCH] net/qrtr: restrict " Sabyrzhan Tasbolatov
2021-02-22 8:45 ` Eric Dumazet
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