5.5

CVE-2022-48862

In the Linux kernel, the following vulnerability has been resolved:

vhost: fix hung thread due to erroneous iotlb entries

In vhost_iotlb_add_range_ctx(), range size can overflow to 0 when
start is 0 and last is ULONG_MAX. One instance where it can happen
is when userspace sends an IOTLB message with iova=size=uaddr=0
(vhost_process_iotlb_msg). So, an entry with size = 0, start = 0,
last = ULONG_MAX ends up in the iotlb. Next time a packet is sent,
iotlb_access_ok() loops indefinitely due to that erroneous entry.

	Call Trace:
	 <TASK>
	 iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340
	 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366
	 vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104
	 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372
	 kthread+0x2e9/0x3a0 kernel/kthread.c:377
	 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
	 </TASK>

Reported by syzbot at:
	https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87

To fix this, do two things:

1. Return -EINVAL in vhost_chr_write_iter() when userspace asks to map
   a range with size 0.
2. Fix vhost_iotlb_add_range_ctx() to handle the range [0, ULONG_MAX]
   by splitting it into two entries.
Data is provided by the National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 5.7 < 5.15.29
Linux ≫ Linux Kernel Version >= 5.16 < 5.16.15
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.03% 0.081
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.