Bug 1594170 (CVE-2018-12633) - CVE-2018-12633 kernel: Double-fetch vulnerability in drivers/virt/vboxguest/vboxguest_linux.c:vbg_misc_device_ioctl() allows information leak and local denial of service
Summary: CVE-2018-12633 kernel: Double-fetch vulnerability in drivers/virt/vboxguest/v...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2018-12633
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
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Depends On: 1594172 1594173
Blocks: 1698114
TreeView+ depends on / blocked
 
Reported: 2018-06-22 09:54 UTC by Adam Mariš
Modified: 2019-09-29 14:42 UTC (History)
41 users (show)

Fixed In Version:
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Last Closed: 2019-04-09 16:07:10 UTC
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Description Adam Mariš 2018-06-22 09:54:14 UTC 
An issue was discovered in the Linux kernel through 4.17.2. vbg_misc_device_ioctl() in drivers/virt/vboxguest/vboxguest_linux.c reads the same user data twice with copy_from_user. The header part of the user data is double-fetched, and a malicious user thread can tamper with the critical variables (hdr.size_in and hdr.size_out) in the header between the two fetches because of a race condition, leading to severe kernel errors, such as buffer over-accesses. This bug can cause a local denial of service and information leakage.

References:

https://bugzilla.kernel.org/show_bug.cgi?id=200131
https://github.com/torvalds/linux/commit/bd23a7269834dc7c1f93e83535d16ebc44b75eba
Comment 1 Adam Mariš 2018-06-22 10:01:25 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1594172]
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