This is a note to let you know that I've just added the patch titled kcm: fix a socket double free to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kcm-fix-a-socket-double-free.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed Sep 21 10:05:18 CEST 2016 From: WANG Cong <xiyou.wangcong@xxxxxxxxx> Date: Sun, 28 Aug 2016 21:28:26 -0700 Subject: kcm: fix a socket double free From: WANG Cong <xiyou.wangcong@xxxxxxxxx> [ Upstream commit c0338aff2260ea6c092806312dbb154cec07a242 ] Dmitry reported a double free on kcm socket, which could be easily reproduced by: #include <unistd.h> #include <sys/syscall.h> int main() { int fd = syscall(SYS_socket, 0x29ul, 0x5ul, 0x0ul, 0, 0, 0); syscall(SYS_ioctl, fd, 0x89e2ul, 0x20a98000ul, 0, 0, 0); return 0; } This is because on the error path, after we install the new socket file, we call sock_release() to clean up the socket, which leaves the fd pointing to a freed socket. Fix this by calling sys_close() on that fd directly. Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Tom Herbert <tom@xxxxxxxxxxxxxxx> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/kcm/kcmsock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -13,6 +13,7 @@ #include <linux/socket.h> #include <linux/uaccess.h> #include <linux/workqueue.h> +#include <linux/syscalls.h> #include <net/kcm.h> #include <net/netns/generic.h> #include <net/sock.h> @@ -2035,7 +2036,7 @@ static int kcm_ioctl(struct socket *sock if (copy_to_user((void __user *)arg, &info, sizeof(info))) { err = -EFAULT; - sock_release(newsock); + sys_close(info.fd); } } Patches currently in stable-queue which might be from xiyou.wangcong@xxxxxxxxx are queue-4.7/kcm-fix-a-socket-double-free.patch queue-4.7/tcp-fix-use-after-free-in-tcp_xmit_retransmit_queue.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html