| Message ID | 20231204180037.383583-1-prarit@redhat.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | ACPI: extlog fix null dereference check | expand |
Top posting and just adding a few interested parties ... On 12/4/23 13:00, Prarit Bhargava wrote: > 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 dereference check in extlog_exit(). > > [1] https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/Static-Analyzer-Options.html > > CC: "Rafael J. Wysocki" <rafael@kernel.org> > CC: Len Brown <lenb@kernel.org> > CC: linux-acpi@vger.kernel.org > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > --- > drivers/acpi/acpi_extlog.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c > index e120a96e1eae..193147769146 100644 > --- a/drivers/acpi/acpi_extlog.c > +++ b/drivers/acpi/acpi_extlog.c > @@ -303,9 +303,10 @@ static int __init extlog_init(void) > 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);
On Mon, Dec 4, 2023 at 7:00 PM Prarit Bhargava <prarit@redhat.com> wrote: > > 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 dereference check in extlog_exit(). > > [1] https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/Static-Analyzer-Options.html > > CC: "Rafael J. Wysocki" <rafael@kernel.org> > CC: Len Brown <lenb@kernel.org> > CC: linux-acpi@vger.kernel.org > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > --- > drivers/acpi/acpi_extlog.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c > index e120a96e1eae..193147769146 100644 > --- a/drivers/acpi/acpi_extlog.c > +++ b/drivers/acpi/acpi_extlog.c > @@ -303,9 +303,10 @@ static int __init extlog_init(void) > 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); > -- Applied as 6.8 material with minor edits in the subject and changelog, thanks!
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c index e120a96e1eae..193147769146 100644 --- a/drivers/acpi/acpi_extlog.c +++ b/drivers/acpi/acpi_extlog.c @@ -303,9 +303,10 @@ static int __init extlog_init(void) 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);
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 dereference check in extlog_exit(). [1] https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/Static-Analyzer-Options.html CC: "Rafael J. Wysocki" <rafael@kernel.org> CC: Len Brown <lenb@kernel.org> CC: linux-acpi@vger.kernel.org Signed-off-by: Prarit Bhargava <prarit@redhat.com> --- drivers/acpi/acpi_extlog.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)