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.

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.

hw: cpu: AMD CPUs may transiently execute beyond unconditional direct branch kernel: ext4: kernel bug in ext4_write_inline_data_end() kernel: malicious data for FBIOPUT_VSCREENINFO ioctl may cause OOB write memory kernel: hwmon: (mlxreg-fan) Return non-zero value when fan current state is enforced from sysfs kernel: mlxsw: thermal: Fix out-of-bounds memory accesses kernel: mlxsw: spectrum: Protect driver from buggy firmware kernel: net: stmmac: fix tc flower deletion for VLAN priority Rx steering kernel: can: etas_es58x: es58x_rx_err_msg(): fix memory leak in error path kernel: possible race condition in drivers/tty/tty_buffers.c kernel: KVM: NULL pointer dereference in kvm_mmu_invpcid_gva kernel: use-after-free in free_pipe_info() could lead to privilege escalation kernel: KVM: nVMX: missing IBPB when exiting from nested guest can lead to Spectre v2 attacks kernel: netfilter: nf_conntrack_irc message handling issue kernel: race condition in xfrm_probe_algs can lead to OOB read/write kernel: out-of-bounds read in fib_nh_match of the file net/ipv4/fib_semantics.c kernel: race condition in hugetlb_no_page() in mm/hugetlb.c kernel: memory leak in ipv6_renew_options() kernel: data races around icsk->icsk_af_ops in do_ipv6_setsockopt kernel: data races around sk->sk_prot kernel: memory leak in l2cap_recv_acldata of the file net/bluetooth/l2cap_core.c kernel: denial of service in follow_page_pte in mm/gup.c due to poisoned pte entry kernel: use-after-free after failed devlink relo…

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 101 more

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.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen und um nicht nähere beschriebene Effekte zu verursachen.