CVE-2022-50350
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk16th percentile - higher than 16% of all known CVEs
Summary
A race condition between login_work and the login thread in the Linux kernel's iSCSI target subsystem was found. A malicious initiator can send data after a login PDU, causing login_work to never stop and, after connection drop, a freed socket structure is dereferenced, leading to a kernel crash.
Risk Assessment
An attacker can cause a kernel panic, resulting in service disruption and potential data loss.
Recommendation
Apply a Linux kernel update containing the fix that forces login_work to stop after login completion and socket callbacks are restored.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: scsi: target: iscsi: Fix a race condition between login_work and the login thread In case a malicious initiator sends some random data immediately after a login PDU; the iscsi_target_sk_data_ready() callback will schedule the login_work and, at the same time, the negotiation may end without clearing the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are required to complete the login). The login has been completed but the login_work function will find the LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling itself; at this point, if the initiator drops the connection, the iscsit_conn structure will be freed, login_work will dereference a released socket structure and the kernel crashes. BUG: kernel NULL pointer dereference, address: 0000000000000230 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod] RIP: 0010:_raw_read_lock_bh+0x15/0x30 Call trace: iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod] process_one_work+0x1e8/0x3c0 Fix this bug by forcing login_work to stop after the login has been completed and the socket callbacks have been restored. Add a comment to clearify the return values of iscsi_target_do_login()

