Red Hat Security Advisory: kernel security update

Important

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix potential double free on mesh join While commit 6a01afcf8468 ("mac80211: mesh: Free ie data when leaving mesh") fixed a memory leak on mesh leave / teardown it introduced a potential memory corruption caused by a double free when rejoining the mesh: ieee80211_leave_mesh() -> kfree(sdata->u.mesh.ie); ... ieee80211_join_mesh() -> copy_mesh_setup() -> old_ie = ifmsh->ie; -> kfree(old_ie); This double free / kernel panics can be reproduced by using wpa_supplicant with an encrypted mesh (if set up without encryption via "iw" then ifmsh->ie is always NULL, which avoids this issue). And then calling: $ iw dev mesh0 mesh leave $ iw dev mesh0 mesh join my-mesh Note that typically these commands are not used / working when using wpa_supplicant. And it seems that wpa_supplicant or wpa_cli are going through a NETDEV_DOWN/NETDEV_UP cycle between a mesh leave and mesh join where the NETDEV_UP resets the mesh.ie to NULL via a memcpy of default_mesh_setup in cfg80211_netdev_notifier_call, which then avoids the memory corruption, too. The issue was first observed in an application which was not using wpa_supplicant but "Senf" instead, which implements its own calls to nl80211. Fixing the issue by removing the kfree()'ing of the mesh IE in the mesh join function and leaving it solely up to the mesh leave to free the mesh IE.

CWE-415 - Double Free

An out of bounds (OOB) memory access flaw was found in the Linux kernel's ipv6 network subsystem. This could allow a local attacker to crash the system or leak kernel internal information.

CWE-125 - Out-of-bounds Read

A use-after-free flaw exists in the Linux kernel’s media/rc subsystem. When the device is disconnected via imon_disconnect(), the driver may unconditionally release a usb_device reference (via usb_put_dev) even while other operations (such as vfd_write, send_packet, display_open, lcd_write) are still in progress. Because the pointers usbdev_intf0/usbdev_intf1 are not properly protected by a users-counter or locking, this situation can lead to a use-after-free of the usb_device pointer and therefore memory corruption or kernel stability issues

CWE-416 - Use After Free

A flaw was found in the Linux kernel's `vsock` component. This vulnerability occurs when a `connect()` operation on an already established socket is interrupted by a signal or timeout, causing the system to mishandle the socket's state. This incorrect handling can lead to a race condition, potentially resulting in memory corruption, such as a use-after-free or null-pointer dereference. A local attacker could exploit this to cause a denial of service or potentially escalate privileges.

CWE-364 - Signal Handler Race Condition

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Validate command header size against SVGA_CMD_MAX_DATASIZE This data originates from userspace and is used in buffer offset calculations which could potentially overflow causing an out-of-bounds access.

CWE-190 - Integer Overflow or Wraparound