cbcvebase.
CVE-2025-40048
published 2025-10-28

CVE-2025-40048: In the Linux kernel, the following vulnerability has been resolved: uio_hv_generic: Let userspace take care of interrupt mask Remove the logic to set interrupt…

PriorityP342high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.60%
45.4th percentile
In the Linux kernel, the following vulnerability has been resolved: uio_hv_generic: Let userspace take care of interrupt mask Remove the logic to set interrupt mask by default in uio_hv_generic driver as the interrupt mask value is supposed to be controlled completely by the user space. If the mask bit gets changed by the driver, concurrently with user mode operating on the ring, the mask bit may be set when it is supposed to be clear, and the user-mode driver will miss an interrupt which will cause a hang. For eg- when the driver sets inbound ring buffer interrupt mask to 1, the host does not interrupt the guest on the UIO VMBus channel. However, setting the mask does not prevent the host from putting a message in the inbound ring buffer. So let’s assume that happens, the host puts a message into the ring buffer but does not interrupt. Subsequently, the user space code in the guest sets the inbound ring buffer interrupt mask to 0, saying “Hey, I’m ready for interrupts”. User space code then calls pread() to wait for an interrupt. Then one of two things happens: * The host never sends another message. So the pread() waits forever. * The host does send another message. But because there’s already a message in the ring buffer, it doesn’t generate an interrupt. This is the correct behavior, because the host should only send an interrupt when the inbound ring buffer transitions from empty to not-empty. Adding an additional message to a ring buffer that is not empty is not supposed to generate an interrupt on the guest. Since the guest is waiting in pread() and not removing messages from the ring buffer, the pread() waits forever. This could be easily reproduced in hv_fcopy_uio_daemon if we delay setting interrupt mask to 0. Similarly if hv_uio_channel_cb() sets the interrupt_mask to 1, there’s a race condition. Once user space empties the inbound ring buffer, but before user space sets interrupt_mask to 0, the host could put another message in the ring buffer but

Affected

32 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.158-1 (bookworm)linux 6.1.158-1 (bookworm)
debianlinux-6.1< linux 6.1.158-1 (bookworm)linux 6.1.158-1 (bookworm)
linuxlinux
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < 540aac117eaea5723cef5e4cbf3035c4ac654d92540aac117eaea5723cef5e4cbf3035c4ac654d92
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < 65d40acd911c7011745cbbd2aaac34eb5266d11e65d40acd911c7011745cbbd2aaac34eb5266d11e
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < a44f61f878f32071d6378e8dd7c2d47f9490c8f7a44f61f878f32071d6378e8dd7c2d47f9490c8f7
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < 01ce972e6f9974a7c76943bcb7e93746917db83a01ce972e6f9974a7c76943bcb7e93746917db83a
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < 2af39ab5e6dc46b835a52e80a22d0cad430985e32af39ab5e6dc46b835a52e80a22d0cad430985e3
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < 37bd91f22794dc05436130d6983302cb90ecfe7e37bd91f22794dc05436130d6983302cb90ecfe7e
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < e29587c07537929684faa365027f4b0d87521e1be29587c07537929684faa365027f4b0d87521e1b
linuxlinux>= 95096f2fbd10186d3e78a328b327afc71428f65f < b15b7d2a1b09ef5428a8db260251897405a19496b15b7d2a1b09ef5428a8db260251897405a19496
linuxlinux_kernel>= 0 < 5.10.247-15.10.247-1
linuxlinux_kernel>= 0 < 6.1.158-16.1.158-1
linuxlinux_kernel>= 0 < 6.12.57-16.12.57-1
linuxlinux_kernel>= 0 < 6.17.6-16.17.6-1
linuxlinux_kernel>= 0 < 5.15.0-170.1805.15.0-170.180
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 4.10.0 < 5.4.3015.4.301
linuxlinux_kernel>= 5.11.0 < 5.15.1955.15.195
linuxlinux_kernel>= 5.16.0 < 6.1.1566.1.156
linuxlinux_kernel>= 5.5.0 < 5.10.2465.10.246
linuxlinux_kernel>= 6.13.0 < 6.17.36.17.3
linuxlinux_kernel>= 6.2.0 < 6.6.1126.6.112
linuxlinux_kernel>= 6.7.0 < 6.12.536.12.53

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_msrc8.4HIGH
vendor_ubuntu7.8HIGH
vendor_redhat6.2MEDIUM
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