In the Linux kernel, the following vulnerability has been resolved:

ACPI: extlog: fix NULL pointer dereference check

The gcc plugin -fanalyzer [1] tries to detect various
patterns of incorrect behaviour.  The tool reports:

drivers/acpi/acpi_extlog.c: In function ‘extlog_exit’:
drivers/acpi/acpi_extlog.c:307:12: warning: check of ‘extlog_l1_addr’ for NULL after already dereferencing it [-Wanalyzer-deref-before-check]
    |
    |  306 |         ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
    |      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
    |      |                                                  |
    |      |                                                  (1) pointer ‘extlog_l1_addr’ is dereferenced here
    |  307 |         if (extlog_l1_addr)
    |      |            ~
    |      |            |
    |      |            (2) pointer ‘extlog_l1_addr’ is checked for NULL here but it was already dereferenced at (1)
    |

Fix the NULL pointer dereference check in extlog_exit().

Linux https://git.kernel.org/stable/c/33650372e3ead97c5ab3b84d9ad97737bc5e00c0 [No types assigned]

Linux https://git.kernel.org/stable/c/5457b0cbaa0238fc56b855c4ef2c0b9cc9c559ab [No types assigned]

Linux https://git.kernel.org/stable/c/72d9b9747e78979510e9aafdd32eb99c7aa30dd1 [No types assigned]

Linux https://git.kernel.org/stable/c/77846571b3ba6a6125a20ad109bb8514ba884cf9 [No types assigned]

Linux https://git.kernel.org/stable/c/b17a71435e7e153e949df018244a98b4ede04069 [No types assigned]

Linux https://git.kernel.org/stable/c/b7b33627be0626b16ca321b982d6a2261ef7f703 [No types assigned]

Linux https://git.kernel.org/stable/c/d2049af7ddbc361702c3e1f09bd6c5e9488454ca [No types assigned]

Linux https://git.kernel.org/stable/c/f066171de33d71ff0f7c46bd17636a5a26db3fb6 [No types assigned]