Re: [PATCH v2 1/2] Revert "net: mdiobus: Fix memory leak in __mdiobus_register"

On 9/29/21 4:39 AM, Pavel Skripkin wrote:

This reverts commit ab609f25d19858513919369ff3d9a63c02cd9e2e.

This patch is correct in the sense that we_should_  call device_put() in
case of device_register() failure, but the problem in this code is more
vast.

We need to set bus->state to UNMDIOBUS_REGISTERED before calling
device_register() to correctly release the device in mdiobus_free().
This patch prevents us from doing it, since in case of device_register()
failure put_device() will be called 2 times and it will cause UAF or
something else.

Also, Reported-by: tag in revered commit was wrong, since syzbot
reported different leak in same function.

Link:https://lore.kernel.org/netdev/20210928092657.GI2048@kadam/ (local)
Cc: Yanfei Xu<redacted>
Signed-off-by: Pavel Skripkin<redacted>
---

Changes in v2:
         Added this revert

Acked-by: Yanfei Xu<redacted>

Thanks,
Yanfei