2022-03-01 03:55:48

by Hangyu Hua

[permalink] [raw]
Subject: [PATCH 4.14 0/2] usb: gadget: use after free in dev_config

Author: Hangyu Hua <[email protected]>
commit 89f3594d0de5 ("usb: gadget: don't release an existing dev->buf")

Author: Hangyu Hua <[email protected]>
commit 501e38a5531e ("usb: gadget: clear related members when goto fail")

Add two commits to all stable branches.

There are two bugs:
dev->buf does not need to be released if it already exists before
executing dev_config.
dev->config and dev->hs_config and dev->dev need to be cleaned if
dev_config fails to avoid UAF.

Hangyu Hua (2):
usb: gadget: don't release an existing dev->buf
usb: gadget: clear related members when goto fail

drivers/usb/gadget/legacy/inode.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--
2.25.1


2022-03-01 09:22:11

by Hangyu Hua

[permalink] [raw]
Subject: [PATCH 4.14 1/2] usb: gadget: don't release an existing dev->buf

dev->buf does not need to be released if it already exists before
executing dev_config.

Acked-by: Alan Stern <[email protected]>
Signed-off-by: Hangyu Hua <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Cc: [email protected] #4.4+
---
drivers/usb/gadget/legacy/inode.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index 3b58f4fc0a80..eaad03c0252f 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -1826,8 +1826,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
spin_lock_irq (&dev->lock);
value = -EINVAL;
if (dev->buf) {
+ spin_unlock_irq(&dev->lock);
kfree(kbuf);
- goto fail;
+ return value;
}
dev->buf = kbuf;

--
2.25.1