cbcvebase.
CVE-2024-55916
published 2025-01-11

CVE-2024-55916: 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)…

PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.21%
12.0th percentile
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 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 vm

Affected

24 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.123-1 (bookworm)linux 6.1.123-1 (bookworm)
debianlinux-6.1< linux 6.1.123-1 (bookworm)linux 6.1.123-1 (bookworm)
linuxlinux
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < f091a224a2c82f1e302b1768d73bb6332f687321f091a224a2c82f1e302b1768d73bb6332f687321
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < d81f4e73aff9b861671df60e5100ad25cc16fbf8d81f4e73aff9b861671df60e5100ad25cc16fbf8
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < 042253c57be901bfd19f15b68267442b70f510d5042253c57be901bfd19f15b68267442b70f510d5
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < 718fe694a334be9d1a89eed22602369ac18d6583718fe694a334be9d1a89eed22602369ac18d6583
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < 89fcec5e466b3ac9b376e0d621c71effa1a7983f89fcec5e466b3ac9b376e0d621c71effa1a7983f
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < 3dd7a30c6d7f90afcf19e9b072f572ba524d7ec63dd7a30c6d7f90afcf19e9b072f572ba524d7ec6
linuxlinux>= e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c < 07a756a49f4b4290b49ea46e089cbe6f79ff8d2607a756a49f4b4290b49ea46e089cbe6f79ff8d26
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.234-15.10.234-1
linuxlinux_kernel>= 0 < 6.1.123-16.1.123-1
linuxlinux_kernel>= 0 < 6.12.8-16.12.8-1
linuxlinux_kernel>= 0 < 6.12.8-16.12.8-1
linuxlinux_kernel>= 0 < 5.4.0-211.2315.4.0-211.231
linuxlinux_kernel>= 0 < 5.15.0-135.1465.15.0-135.146
linuxlinux_kernel>= 0 < 6.8.0-60.636.8.0-60.63
linuxlinux_kernel>= 4.9 < 5.4.2895.4.289
linuxlinux_kernel>= 5.11 < 5.15.1765.15.176
linuxlinux_kernel>= 5.16 < 6.1.1226.1.122
linuxlinux_kernel>= 5.5 < 5.10.2335.10.233
linuxlinux_kernel>= 6.2 < 6.6.686.6.68
linuxlinux_kernel>= 6.7 < 6.12.76.12.7

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.