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| author | Prarit Bhargava <prarit@redhat.com> | 2023-12-04 13:00:37 -0500 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-12-06 21:21:09 +0100 |
| commit | 72d9b9747e78979510e9aafdd32eb99c7aa30dd1 (patch) | |
| tree | f17c33056e41d7950d9d35d75bba224ae3f86bc8 /drivers/acpi | |
| parent | 33cc938e65a98f1d29d0a18403dbbee050dcad9a (diff) | |
| download | linux-72d9b9747e78979510e9aafdd32eb99c7aa30dd1.tar.gz | |
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().
Link: https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/Static-Analyzer-Options.html # [1]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/acpi_extlog.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c index e120a96e1eaee8..193147769146ea 100644 --- a/drivers/acpi/acpi_extlog.c +++ b/drivers/acpi/acpi_extlog.c @@ -303,9 +303,10 @@ err: static void __exit extlog_exit(void) { mce_unregister_decode_chain(&extlog_mce_dec); - ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN; - if (extlog_l1_addr) + if (extlog_l1_addr) { + ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN; acpi_os_unmap_iomem(extlog_l1_addr, l1_size); + } if (elog_addr) acpi_os_unmap_iomem(elog_addr, elog_size); release_mem_region(elog_base, elog_size); |