CVE-2021-4441

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