CVE-2024-55916
Hyper-V Drivers: Buffer Not Initialized Yet NULL Pointer Dereference Vulnerability
Description
In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is fully initialized, we can hit the panic below: hv_utils: Registering HyperV Utility Driver hv_vmbus: registering driver hv_utils ... BUG: kernel NULL pointer dereference, address: 0000000000000000 CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1 RIP: 0010:hv_pkt_iter_first+0x12/0xd0 Call Trace: ... vmbus_recvpacket hv_kvp_onchannelcallback vmbus_on_event tasklet_action_common tasklet_action handle_softirqs irq_exit_rcu sysvec_hyperv_stimer0 </IRQ> <TASK> asm_sysvec_hyperv_stimer0 ... kvp_register_done hvt_op_read vfs_read ksys_read __x64_sys_read This can happen because the KVP/VSS channel callback can be invoked even before the channel is fully opened: 1) as soon as hv_kvp_init() -> hvutil_transport_init() creates /dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and register itself to the driver by writing a message KVP_OP_REGISTER1 to the file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and reading the file for the driver's response, which is handled by hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done(). 2) the problem with kvp_register_done() is that it can cause the channel callback to be called even before the channel is fully opened, and when the channel callback is starting to run, util_probe()-> vmbus_open() may have not initialized the ringbuffer yet, so the callback can hit the panic of NULL pointer dereference. To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in __vmbus_open(), just before the first hv_ringbuffer_init(), and then we unload and reload the driver hv_utils, and run the daemon manually within the 10 seconds. Fix the panic by reordering the steps in util_probe() so the char dev entry used by the KVP or VSS daemon is not created until after vmbus_open() has completed. This reordering prevents the race condition from happening.
INFO
Published Date :
Jan. 11, 2025, 1:15 p.m.
Last Modified :
Jan. 16, 2025, 3:18 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
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CVE-2024-55916.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2024-55916 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-55916 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jan. 16, 2025
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NIST CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.9 up to (excluding) 5.4.289 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.233 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.122 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.68 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.7 *cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* Changed Reference Type https://git.kernel.org/stable/c/042253c57be901bfd19f15b68267442b70f510d5 No Types Assigned https://git.kernel.org/stable/c/042253c57be901bfd19f15b68267442b70f510d5 Patch Changed Reference Type https://git.kernel.org/stable/c/07a756a49f4b4290b49ea46e089cbe6f79ff8d26 No Types Assigned https://git.kernel.org/stable/c/07a756a49f4b4290b49ea46e089cbe6f79ff8d26 Patch Changed Reference Type https://git.kernel.org/stable/c/3dd7a30c6d7f90afcf19e9b072f572ba524d7ec6 No Types Assigned https://git.kernel.org/stable/c/3dd7a30c6d7f90afcf19e9b072f572ba524d7ec6 Patch Changed Reference Type https://git.kernel.org/stable/c/718fe694a334be9d1a89eed22602369ac18d6583 No Types Assigned https://git.kernel.org/stable/c/718fe694a334be9d1a89eed22602369ac18d6583 Patch Changed Reference Type https://git.kernel.org/stable/c/89fcec5e466b3ac9b376e0d621c71effa1a7983f No Types Assigned https://git.kernel.org/stable/c/89fcec5e466b3ac9b376e0d621c71effa1a7983f Patch Changed Reference Type https://git.kernel.org/stable/c/d81f4e73aff9b861671df60e5100ad25cc16fbf8 No Types Assigned https://git.kernel.org/stable/c/d81f4e73aff9b861671df60e5100ad25cc16fbf8 Patch Changed Reference Type https://git.kernel.org/stable/c/f091a224a2c82f1e302b1768d73bb6332f687321 No Types Assigned https://git.kernel.org/stable/c/f091a224a2c82f1e302b1768d73bb6332f687321 Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jan. 11, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is fully initialized, we can hit the panic below: hv_utils: Registering HyperV Utility Driver hv_vmbus: registering driver hv_utils ... BUG: kernel NULL pointer dereference, address: 0000000000000000 CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1 RIP: 0010:hv_pkt_iter_first+0x12/0xd0 Call Trace: ... vmbus_recvpacket hv_kvp_onchannelcallback vmbus_on_event tasklet_action_common tasklet_action handle_softirqs irq_exit_rcu sysvec_hyperv_stimer0 </IRQ> <TASK> asm_sysvec_hyperv_stimer0 ... kvp_register_done hvt_op_read vfs_read ksys_read __x64_sys_read This can happen because the KVP/VSS channel callback can be invoked even before the channel is fully opened: 1) as soon as hv_kvp_init() -> hvutil_transport_init() creates /dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and register itself to the driver by writing a message KVP_OP_REGISTER1 to the file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and reading the file for the driver's response, which is handled by hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done(). 2) the problem with kvp_register_done() is that it can cause the channel callback to be called even before the channel is fully opened, and when the channel callback is starting to run, util_probe()-> vmbus_open() may have not initialized the ringbuffer yet, so the callback can hit the panic of NULL pointer dereference. To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in __vmbus_open(), just before the first hv_ringbuffer_init(), and then we unload and reload the driver hv_utils, and run the daemon manually within the 10 seconds. Fix the panic by reordering the steps in util_probe() so the char dev entry used by the KVP or VSS daemon is not created until after vmbus_open() has completed. This reordering prevents the race condition from happening. Added Reference https://git.kernel.org/stable/c/042253c57be901bfd19f15b68267442b70f510d5 Added Reference https://git.kernel.org/stable/c/07a756a49f4b4290b49ea46e089cbe6f79ff8d26 Added Reference https://git.kernel.org/stable/c/3dd7a30c6d7f90afcf19e9b072f572ba524d7ec6 Added Reference https://git.kernel.org/stable/c/718fe694a334be9d1a89eed22602369ac18d6583 Added Reference https://git.kernel.org/stable/c/89fcec5e466b3ac9b376e0d621c71effa1a7983f Added Reference https://git.kernel.org/stable/c/d81f4e73aff9b861671df60e5100ad25cc16fbf8 Added Reference https://git.kernel.org/stable/c/f091a224a2c82f1e302b1768d73bb6332f687321
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-55916 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-55916
weaknesses.