The implementation of lib9p's handling of RWALK messages was missing a bounds check needed when unpacking the message contents. The missing check means that the receipt of a specially crafted message will cause lib9p to overwrite unrelated memory.
The bug can be triggered by a malicious bhyve guest kernel to overwrite memory in the bhyve(8) process. This could potentially lead to user-mode code execution on the host, subject to bhyve's Capsicum sandbox.
A particular case of memory sharing is mishandled in the virtual memory system. This is very similar to SA-21:08.vm, but with a different root cause.
An unprivileged local user process can maintain a mapping of a page after it is freed, allowing that process to read private data belonging to other processes or the kernel.
The aioaqueue function, used by the liolistio system call, fails to release a reference to a credential in an error case.
An attacker may cause the reference count to overflow, leading to a use after free (UAF).
When dumping core and saving process information, procgetargv() might return an sbuf which have a sbuflen() of 0 or -1, which is not properly handled.
An out-of-bound read can happen when user constructs a specially crafted psstring, which in turn can cause the kernel to crash.
The 802.11 beacon handling routine failed to validate the length of an IEEE 802.11s Mesh ID before copying it to a heap-allocated buffer.
While a FreeBSD Wi-Fi client is in scanning mode (i.e., not associated with a SSID) a malicious beacon frame may overwrite kernel memory, leading to remote code execution.
The e1000 network adapters permit a variety of modifications to an Ethernet packet when it is being transmitted. These include the insertion of IP and TCP checksums, insertion of an Ethernet VLAN header, and TCP segmentation offload ("TSO"). The e1000 device model uses an on-stack buffer to generate the modified packet header when simulating these modifications on transmitted packets.
When checksum offload is requested for a transmitted packet, the e1000 device model used a guest-provided value to specify the checksum offset in the on-stack buffer. The offset was not validated for certain packet types.
A misbehaving bhyve guest could overwrite memory in the bhyve process on the host, possibly leading to code execution in the host context.
The bhyve process runs in a Capsicum sandbox, which (depending on the FreeBSD version and bhyve configuration) limits the impact of exploiting this issue.
Handlers for CFGPAGE read / write ioctls in the mpr, mps, and mpt drivers allocated a buffer of a caller-specified size, but copied to it a fixed size header. Other heap content would be overwritten if the specified size was too small.
Users with access to the mpr, mps or mpt device node may overwrite heap data, potentially resulting in privilege escalation. Note that the device node is only accessible to root and members of the operator group.
A user-provided integer option was passed to nmreqcopyin() without checking if it would overflow. This insufficient bounds checking could lead to kernel memory corruption.
On systems configured to include netmap in their devfsruleset, a privileged process running in a jail can affect the host environment.
The total size of the user-provided nmreq to nmreqcopyin() was first computed and then trusted during the copyin. This time-of-check to time-of-use bug could lead to kernel memory corruption.
On systems configured to include netmap in their devfsruleset, a privileged process running in a jail can affect the host environment.
In FreeBSD 13.0-STABLE before n247428-9352de39c3dc, 12.2-STABLE before r370674, 13.0-RELEASE before p6, and 12.2-RELEASE before p12, certain conditions involving use of the highlight buffer while text is scrolling on the console, console data may overwrite data structures associated with the system console or other kernel memory.
In FreeBSD 13.0-STABLE before n245117, 12.2-STABLE before r369551, 11.4-STABLE before r369559, 13.0-RC5 before p1, 12.2-RELEASE before p6, and 11.4-RELEASE before p9, copy-on-write logic failed to invalidate shared memory page mappings between multiple processes allowing an unprivileged process to maintain a mapping after it is freed, allowing the process to read private data belonging to other processes or the kernel.
In FreeBSD 13.0-STABLE before n245050, 12.2-STABLE before r369525, 13.0-RC4 before p0, and 12.2-RELEASE before p6, listening socket accept filters implementing the accfcreate callback incorrectly freed a process supplied argument string. Additional operations on the socket can lead to a double free or use after free.
In FreeBSD 13.0-STABLE before n245118, 12.2-STABLE before r369552, 11.4-STABLE before r369560, 13.0-RC5 before p1, 12.2-RELEASE before p6, and 11.4-RELEASE before p9, a superuser inside a FreeBSD jail configured with the non-default allow.mount permission could cause a race condition between the lookup of ".." and remounting a filesystem, allowing access to filesystem hierarchy outside of the jail.