Am Freitag, den 20.03.2020, 12:28 -0700 schrieb syzbot: > Hello, > > syzbot found the following crash on: > > HEAD commit: e17994d1 usb: core: kcov: collect coverage from usb comple.. > git tree: https://github.com/google/kasan.git usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=11d74573e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60 > dashboard link: https://syzkaller.appspot.com/bug?extid=7d42d68643a35f71ac8a > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fa561de00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15d74573e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+7d42d68643a35f71a...@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:381 [inline] > BUG: KASAN: slab-out-of-bounds in skb_put_data include/linux/skbuff.h:2284 > [inline] > BUG: KASAN: slab-out-of-bounds in hfa384x_int_rxmonitor > drivers/staging/wlan-ng/hfa384x_usb.c:3412 [inline] > BUG: KASAN: slab-out-of-bounds in hfa384x_usbin_rx > drivers/staging/wlan-ng/hfa384x_usb.c:3312 [inline] > BUG: KASAN: slab-out-of-bounds in hfa384x_usbin_callback+0x1993/0x2360 > drivers/staging/wlan-ng/hfa384x_usb.c:3026 > Read of size 19671 at addr ffff8881d226413c by task swapper/0/0
#syz test: https://github.com/google/kasan.git e17994d1
From 6dbcac8c4b645600161feafc5576657905f15d65 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneu...@suse.com> Date: Tue, 5 May 2020 13:46:26 +0200 Subject: [PATCH] hfa384x_usb: fix buffer overflow The driver trusts the data_len coming from the hardware without verification. That means that this opens a vector by which an attacker can smash 64K of the heap. Signed-off-by: Oliver Neukum <oneu...@suse.com> --- drivers/staging/wlan-ng/hfa384x_usb.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/staging/wlan-ng/hfa384x_usb.c b/drivers/staging/wlan-ng/hfa384x_usb.c index fa1bf8b069fd..5b6497d8c9e2 100644 --- a/drivers/staging/wlan-ng/hfa384x_usb.c +++ b/drivers/staging/wlan-ng/hfa384x_usb.c @@ -3353,9 +3353,9 @@ static void hfa384x_int_rxmonitor(struct wlandevice *wlandev, struct hfa384x_usb_rxfrm *rxfrm) { struct hfa384x_rx_frame *rxdesc = &rxfrm->desc; - unsigned int hdrlen = 0; - unsigned int datalen = 0; - unsigned int skblen = 0; + unsigned int hdrlen; + unsigned int datalen; + unsigned int skblen; u8 *datap; u16 fc; struct sk_buff *skb; @@ -3413,8 +3413,10 @@ static void hfa384x_int_rxmonitor(struct wlandevice *wlandev, */ skb_put_data(skb, &rxdesc->frame_control, hdrlen); - /* If any, copy the data from the card to the skb */ - if (datalen > 0) { + /* If any, copy the data from the card to the skb, + * as long as it fits, lest we smash a buffer + */ + if (datalen > 0 && datalen <= skblen - hdrlen) { datap = skb_put_data(skb, rxfrm->data, datalen); /* check for unencrypted stuff if WEP bit set. */ -- 2.16.4
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