CVE-2022-50459

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: iscsi: iscsi_tcp: Fix null-ptr-deref while calling getpeername() Fix a NULL pointer crash that occurs when we are freeing the socket at the same time we access it via sysfs. The problem is that: 1. iscsi_sw_tcp_conn_get_param() and iscsi_sw_tcp_host_get_param() take the frwd_lock and do sock_hold() then drop the frwd_lock. sock_hold() does a get on the "struct sock". 2. iscsi_sw_tcp_release_conn() does sockfd_put() which does the last put on the "struct socket" and that does __sock_release() which sets the sock->ops to NULL. 3. iscsi_sw_tcp_conn_get_param() and iscsi_sw_tcp_host_get_param() then call kernel_getpeername() which accesses the NULL sock->ops. Above we do a get on the "struct sock", but we needed a get on the "struct socket". Originally, we just held the frwd_lock the entire time but in commit bcf3a2953d36 ("scsi: iscsi: iscsi_tcp: Avoid holding spinlock while calling getpeername()") we switched to refcount based because the network layer changed and started taking a mutex in that path, so we could no longer hold the frwd_lock. Instead of trying to maintain multiple refcounts, this just has us use a mutex for accessing the socket in the interface code paths.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/884a788f065578bb640382279a83d1df433b13e6 ↗
• https://git.kernel.org/stable/c/a26b0658751bb0a3b28386fca715333b104d32a2 ↗
• https://git.kernel.org/stable/c/897dbbc57d71e8a34ec1af8e573a142de457da38 ↗
• https://git.kernel.org/stable/c/0a0b861fce2657ba08ec356a74346b37ca4b2008 ↗
• https://git.kernel.org/stable/c/57569c37f0add1b6489e1a1563c71519daf732cf ↗