cbcvebase.
CVE-2024-26603
published 2024-02-26

CVE-2024-26603: In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Stop relying on userspace for info to fault in xsave buffer Before this change…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.28%
20.0th percentile
In the Linux kernel, the following vulnerability has been resolved:

x86/fpu: Stop relying on userspace for info to fault in xsave buffer

Before this change, the expected size of the user space buffer was
taken from fx_sw->xstate_size. fx_sw->xstate_size can be changed
from user-space, so it is possible construct a sigreturn frame where:

* fx_sw->xstate_size is smaller than the size required by valid bits in
fx_sw->xfeatures.
* user-space unmaps parts of the sigrame fpu buffer so that not all of
the buffer required by xrstor is accessible.

In this case, xrstor tries to restore and accesses the unmapped area
which results in a fault. But fault_in_readable succeeds because buf +
fx_sw->xstate_size is within the still mapped area, so it goes back and
tries xrstor again. It will spin in this loop forever.

Instead, fault in the maximum size which can be touched by XRSTOR (taken
from fpstate->user_size).

[ dhansen: tweak subject / changelog ]

Affected

15 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.82-1 (bookworm)linux 6.1.82-1 (bookworm)
linuxlinux
linuxlinux>= fcb3635f5018e53024c6be3c3213737f469f74ff < 8bd3eee7720c14b59a206bd05b98d7586bccf99a8bd3eee7720c14b59a206bd05b98d7586bccf99a
linuxlinux>= fcb3635f5018e53024c6be3c3213737f469f74ff < 627339cccdc9166792ecf96bc3c9f711a60ce996627339cccdc9166792ecf96bc3c9f711a60ce996
linuxlinux>= fcb3635f5018e53024c6be3c3213737f469f74ff < b2479ab426cef7ab79a13005650eff956223ced2b2479ab426cef7ab79a13005650eff956223ced2
linuxlinux>= fcb3635f5018e53024c6be3c3213737f469f74ff < 627e28cbb65564e55008315d9e02fbb90478beda627e28cbb65564e55008315d9e02fbb90478beda
linuxlinux>= fcb3635f5018e53024c6be3c3213737f469f74ff < d877550eaf2dc9090d782864c96939397a3c6835d877550eaf2dc9090d782864c96939397a3c6835
linuxlinux_kernel>= 0 < 6.1.82-16.1.82-1
linuxlinux_kernel>= 0 < 6.7.7-16.7.7-1
linuxlinux_kernel>= 0 < 6.7.7-16.7.7-1
linuxlinux_kernel>= 0 < 5.15.0-112.1225.15.0-112.122
linuxlinux_kernel>= 5.14.0 < 5.15.1505.15.150
linuxlinux_kernel>= 5.16.0 < 6.1.796.1.79
linuxlinux_kernel>= 6.2.0 < 6.6.186.6.18
linuxlinux_kernel>= 6.7.0 < 6.7.66.7.6

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.0HIGH
vendor_ubuntu7.0HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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