On 4/16/21 2:53 PM, Tom Seewald wrote:
From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> commit 4e9c93af7279b059faf5bb1897ee90512b258a12 upstream. Fuzzing uncovered race condition between sysfs code paths in usbip drivers. Device connect/disconnect code paths initiated through sysfs interface are prone to races if disconnect happens during connect and vice versa. This problem is common to all drivers while it can be reproduced easily in vhci_hcd. Add a sysfs_lock to usbip_device struct to protect the paths. Use this in vhci_hcd to protect sysfs paths. For a complete fix, usip_host and usip-vudc drivers and the event handler will have to use this lock to protect the paths. These changes will be done in subsequent patches. Cc: stable@xxxxxxxxxxxxxxx # 4.9.x Reported-and-tested-by: syzbot+a93fba6d384346a761e3@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/b6568f7beae702bbc236a545d3c020106ca75eac.1616807117.git.skhan@xxxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Tom Seewald <tseewald@xxxxxxxxx> --- drivers/usb/usbip/usbip_common.h | 3 +++ drivers/usb/usbip/vhci_hcd.c | 1 + drivers/usb/usbip/vhci_sysfs.c | 30 +++++++++++++++++++++++++----- 3 files changed, 29 insertions(+), 5 deletions(-)
Thank you for the backport. Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Greg, please pick this up for 4.9.x thanks, -- Shuah
