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authorZeng Tao <prime.zeng@hisilicon.com>2020-09-04 09:37:44 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-04 17:41:22 +0300
commita18cd6c9b6bc73dc17e8b7e9bd07decaa8833c97 (patch)
tree20129da790355f03bdc1ac902e036b550c170952 /drivers/usb
parenta6498d51821edf9615b42b968fb419a40197a982 (diff)
downloadlinux-a18cd6c9b6bc73dc17e8b7e9bd07decaa8833c97.tar.xz
usb: core: fix slab-out-of-bounds Read in read_descriptors
The USB device descriptor may get changed between two consecutive enumerations on the same device for some reason, such as DFU or malicius device. In that case, we may access the changing descriptor if we don't take the device lock here. The issue is reported: https://syzkaller.appspot.com/bug?id=901a0d9e6519ef8dc7acab25344bd287dd3c7be9 Cc: stable <stable@vger.kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Reported-by: syzbot+256e56ddde8b8957eabd@syzkaller.appspotmail.com Fixes: 217a9081d8e6 ("USB: add all configs to the "descriptors" attribute") Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Link: https://lore.kernel.org/r/1599201467-11000-1-git-send-email-prime.zeng@hisilicon.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/core/sysfs.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index a2ca38e25e0c..8d134193fa0c 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -889,7 +889,11 @@ read_descriptors(struct file *filp, struct kobject *kobj,
size_t srclen, n;
int cfgno;
void *src;
+ int retval;
+ retval = usb_lock_device_interruptible(udev);
+ if (retval < 0)
+ return -EINTR;
/* The binary attribute begins with the device descriptor.
* Following that are the raw descriptor entries for all the
* configurations (config plus subsidiary descriptors).
@@ -914,6 +918,7 @@ read_descriptors(struct file *filp, struct kobject *kobj,
off -= srclen;
}
}
+ usb_unlock_device(udev);
return count - nleft;
}