Linux Kernel up to 5.4.181/5.10.102/5.15.25/5.16.11 spi zynq_qspi_exec_mem_op null pointer dereference

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 5.4.181/5.10.102/5.15.25/5.16.11. This affects the function zynq_qspi_exec_mem_op of the component spi. Such manipulation leads to null pointer dereference. This vulnerability is uniquely identified as CVE-2021-4441. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.4.181/5.10.102/5.15.25/5.16.11. Affected by this issue is the function zynq_qspi_exec_mem_op of the component spi. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op() In zynq_qspi_exec_mem_op(), kzalloc() is directly used in memset(), which could lead to a NULL pointer dereference on failure of kzalloc(). Fix this bug by adding a check of tmpbuf. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_SPI_ZYNQ_QSPI=m show no new warnings, and our static analyzer no longer warns about this code.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-4441 since 08/22/2024. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

Upgrading to version 5.4.182, 5.10.103, 5.15.26 or 5.16.12 eliminates this vulnerability. Applying the patch df14d2bed8e2/2efece1368ae/3c32405d6474/b9dd08cbebe0/ab3824427b84 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.181
• 5.10.102
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9
• 5.16.10
• 5.16.11

License

• open-source

Website

• Vendor: https://www.kernel.org/

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