UBUNTU-CVE-2026-46148
In the Linux kernel, the following vulnerability has been resolved: spi: microchip-core-qspi: control built-in cs manually The coreQSPI IP supports only a single chip select, which is automagically operated by the hardware - set low when the transmit buffer first gets written to and set high when the number of bytes written to the TOTALBYTES field of the FRAMES register have been sent on the bus. Additional devices must use GPIOs for their chip selects. It was reported to me that if there are two devices attached to this QSPI controller that the in-built chip select is set low while linux tries to access the device attached to the GPIO. This went undetected as the boards that connected multiple devices to the SPI controller all exclusively used GPIOs for chip selects, not relying on the built-in chip select at all. It turns out that this was because the built-in chip select, when controlled automagically, is set low when active and high when inactive, thereby ruling out its use for active-high devices or devices that need to transmit with the chip select disabled. Modify the driver so that it controls chip select directly, retaining the behaviour for mem_ops of setting the chip select active for the entire duration of the transfer in the exec_op callback. For regular transfers, implement the set_cs callback for the core to use. As part of this, the existing setup callback, mchp_coreqspi_setup_op(), is removed. Modifying the CLKIDLE field is not safe to do during operation when there are multiple devices, so this code is removed entirely. Setting the MASTER and ENABLE fields is something that can be done once at probe, it doesn't need to be re-run for each device. Instead the new setup callback sets the built-in chip select to its inactive state for active-low devices, as the reset value of the chip select in software controlled mode is low.
02 / AFFECTED SOFTWARE
Affected packages
10 explicit affected versions
39 explicit affected versions
46 explicit affected versions
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29 explicit affected versions
13 explicit affected versions
12 explicit affected versions
43 explicit affected versions
10 explicit affected versions
23 explicit affected versions
10 explicit affected versions
3 explicit affected versions
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51 explicit affected versions
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13 explicit affected versions
10 explicit affected versions
8 explicit affected versions
48 explicit affected versions
1 explicit affected versions
22 explicit affected versions
10 explicit affected versions
10 explicit affected versions
11 explicit affected versions
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12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
6 explicit affected versions
2 explicit affected versions
21 explicit affected versions
12 explicit affected versions
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10 explicit affected versions
6 explicit affected versions
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26 explicit affected versions
7 explicit affected versions
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13 explicit affected versions
8 explicit affected versions
35 explicit affected versions
1 explicit affected versions
18 explicit affected versions
1 explicit affected versions
48 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
55 explicit affected versions
1 explicit affected versions
9 explicit affected versions
16 explicit affected versions
10 explicit affected versions
20 explicit affected versions
7 explicit affected versions
51 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
19 explicit affected versions
12 explicit affected versions
10 explicit affected versions
44 explicit affected versions
9 explicit affected versions
9 explicit affected versions
16 explicit affected versions
6 explicit affected versions
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29 explicit affected versions
37 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
17 explicit affected versions
42 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
12 explicit affected versions
43 explicit affected versions
8 explicit affected versions
33 explicit affected versions
23 explicit affected versions
6 explicit affected versions
10 explicit affected versions
22 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
10 explicit affected versions
16 explicit affected versions
5 explicit affected versions
7 explicit affected versions
26 explicit affected versions
42 explicit affected versions
37 explicit affected versions
48 explicit affected versions
11 explicit affected versions
26 explicit affected versions
13 explicit affected versions
48 explicit affected versions
16 explicit affected versions
53 explicit affected versions
16 explicit affected versions
18 explicit affected versions
43 explicit affected versions
12 explicit affected versions
21 explicit affected versions
7 explicit affected versions
27 explicit affected versions
3 explicit affected versions
8 explicit affected versions
45 explicit affected versions
8 explicit affected versions
3 explicit affected versions
5 explicit affected versions
8 explicit affected versions
14 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
45 explicit affected versions
37 explicit affected versions
53 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
17 explicit affected versions
11 explicit affected versions
42 explicit affected versions
8 explicit affected versions
7 explicit affected versions
4 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
13 explicit affected versions
43 explicit affected versions
16 explicit affected versions
5 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
14 explicit affected versions
11 explicit affected versions
6 explicit affected versions
41 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: spi: microchip-core-qspi: control built-in cs manually The coreQSPI IP supports only a single chip select, which is automagically operated by the hardware - set low when the transmit buffer first gets written to and set high when the number of bytes written to the TOTALBYTES field of the FRAMES register have been sent on the bus. Additional devices must use GPIOs for their chip selects. It was reported to me that if there are two devices attached to this QSPI controller that the in-built chip select is set low while linux tries to access the device attached to the GPIO. This went undetected as the boards that connected multiple devices to the SPI controller all exclusively used GPIOs for chip selects, not relying on the built-in chip select at all. It turns out that this was because the built-in chip select, when controlled automagically, is set low when active and high when inactive, thereby ruling out its use for active-high devices or devices that need to transmit with the chip select disabled. Modify the driver so that it controls chip select directly, retaining the behaviour for mem_ops of setting the chip select active for the entire duration of the transfer in the exec_op callback. For regular transfers, implement the set_cs callback for the core to use. As part of this, the existing setup callback, mchp_coreqspi_setup_op(), is removed. Modifying the CLKIDLE field is not safe to do during operation when there are multiple devices, so this code is removed entirely. Setting the MASTER and ENABLE fields is something that can be done once at probe, it doesn't need to be re-run for each device. Instead the new setup callback sets the built-in chip select to its inactive state for active-low devices, as the reset value of the chip select in software controlled mode is low.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/7672749e1496215e8683ce57cf323119033954cf
- https://git.kernel.org/stable/c/7672749e1496215e8683ce57cf323119033954cf
- https://git.kernel.org/stable/c/998f43196d732f20f9b71eb6ebd973736c9fa911
- https://git.kernel.org/stable/c/ee3c99aa102212ad59dc2c19595515c4a6729307
- https://ubuntu.com/security/CVE-2026-46148
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://www.cve.org/CVERecord?id=CVE-2026-46148