lkml.org 
[lkml]   [2021]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.19 35/50] net/qrtr: restrict user-controlled length in qrtr_tun_write_iter()
Date
From: Sabyrzhan Tasbolatov <snovitoll@gmail.com>

commit 2a80c15812372e554474b1dba0b1d8e467af295d upstream.

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>
Link: https://lore.kernel.org/r/20210202092059.1361381-1-snovitoll@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/qrtr/tun.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/net/qrtr/tun.c
+++ b/net/qrtr/tun.c
@@ -80,6 +80,12 @@ static ssize_t qrtr_tun_write_iter(struc
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;

\
 
 \ /
  Last update: 2021-02-22 13:53    [W:0.174 / U:12.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site