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authorSabyrzhan Tasbolatov <snovitoll@gmail.com>2021-02-02 15:20:59 +0600
committerJakub Kicinski <kuba@kernel.org>2021-02-03 16:29:06 -0800
commit2a80c15812372e554474b1dba0b1d8e467af295d (patch)
tree153898b70dc17995b02f7da69b1fabb49ed5eb7c /net/qrtr
parenta4dc7eee9106a9d2a6e08b442db19677aa9699c7 (diff)
net/qrtr: restrict user-controlled length in qrtr_tun_write_iter()
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>
Diffstat (limited to 'net/qrtr')
-rw-r--r--net/qrtr/tun.c6
1 files changed, 6 insertions, 0 deletions
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;