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| author | Sabyrzhan Tasbolatov <snovitoll@gmail.com> | 2021-02-02 15:20:59 +0600 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-03 16:29:06 -0800 |
| commit | 2a80c15812372e554474b1dba0b1d8e467af295d (patch) | |
| tree | 153898b70dc17995b02f7da69b1fabb49ed5eb7c /net/qrtr | |
| parent | a4dc7eee9106a9d2a6e08b442db19677aa9699c7 (diff) | |
| download | lwn-2a80c15812372e554474b1dba0b1d8e467af295d.tar.gz lwn-2a80c15812372e554474b1dba0b1d8e467af295d.zip | |
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.c | 6 |
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; |