A vulnerability was found in the Linux kernel's vsock subsystem's vsock_stream_connect() function where improper handling of the socket state can lead to the connected table's list being corrupted. This occurs when a signal interrupt occurs and resets the socket's state without removing it from the connected table; the process then attempts the connect() function again, which if successful, can lead to the socket being added a second time to the connected table, corrupting the linked list structure used for managing connected sockets. This vulnerability can potentially lead to memory corruption and system instability.
In the Linux kernel, the following vulnerability has been resolved:
vsock: remove vsock from connected table when connect is interrupted by a signal
vsock_connect() expects that the socket could already be in the
TCP_ESTABLISHED state when the connecting task wakes up with a signal
pending. If this happens the socket will be in the connected table, and
it is not removed when the socket state is reset. In this situation it's
common for the process to retry connect(), and if the connection is
successful the socket will be added to the connected table a second
time, corrupting the list.
Prevent this by calling vsock_remove_connected() if a signal is received
while waiting for a connection. This is harmless if the socket is not in
the connected table, and if it is in the table then removing it will
prevent list corruption from a double add.
Note for backporting: this patch requires d5afa82c977e ("vsock: correct
removal of socket from the list"), which is in all current stable trees
except 4.9.y.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
Red Hat Enterprise Linux 8.6 Telecommunications Update Service
Via RHSA-2024:10273 https://access.redhat.com/errata/RHSA-2024:10273
In the Linux kernel, the following vulnerability has been resolved: vsock: remove vsock from connected table when connect is interrupted by a signal vsock_connect() expects that the socket could already be in the TCP_ESTABLISHED state when the connecting task wakes up with a signal pending. If this happens the socket will be in the connected table, and it is not removed when the socket state is reset. In this situation it's common for the process to retry connect(), and if the connection is successful the socket will be added to the connected table a second time, corrupting the list. Prevent this by calling vsock_remove_connected() if a signal is received while waiting for a connection. This is harmless if the socket is not in the connected table, and if it is in the table then removing it will prevent list corruption from a double add. Note for backporting: this patch requires d5afa82c977e ("vsock: correct removal of socket from the list"), which is in all current stable trees except 4.9.y.