Messages in this thread Patch in this message | | | From | Colin King <> | Subject | [PATCH] ACPI / extlog: don't dereference extlog_l1_addr if it is null | Date | Wed, 2 Dec 2015 11:58:28 +0000 |
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From: Colin Ian King <colin.king@canonical.com>
There is a check to see if extlog_l1_addr is null before calling acpi_os_unmap_iomem, however, before that call there is a dereference on this that could trip an oops. Move the extlog_l1_addr dereference so it occurs only if it is not null.
Found by static analysis by smatch.
Signed-off-by: Colin Ian King <colin.king@canonical.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 b3842ff..183b7b2 100644 --- a/drivers/acpi/acpi_extlog.c +++ b/drivers/acpi/acpi_extlog.c @@ -309,9 +309,10 @@ static void __exit extlog_exit(void) { set_edac_report_status(old_edac_report_status); 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); -- 2.6.2
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