With the introduction of KASAN_HW_TAGS, kasan_report() dereferences
the address passed as a parameter.
Add a comment to make sure that the preconditions to the function are
explicitly clarified.
Note: An invalid address (e.g. NULL pointer address) passed to the
function when, KASAN_HW_TAGS is enabled, leads to a kernel panic.
Cc: Andrey Ryabinin <aryabi...@virtuozzo.com>
Cc: Alexander Potapenko <gli...@google.com>
Cc: Dmitry Vyukov <dvyu...@google.com>
Cc: Leon Romanovsky <leo...@mellanox.com>
Cc: Andrey Konovalov <andreyk...@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frasc...@arm.com>
---
mm/kasan/report.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index c0fb21797550..2485b585004d 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -403,6 +403,17 @@ static void __kasan_report(unsigned long addr, size_t
size, bool is_write,
end_report(&flags);
}
+/**
+ * kasan_report - report kasan fault details
+ * @addr: valid address of the allocation where the tag fault was detected
+ * @size: size of the allocation where the tag fault was detected
+ * @is_write: the instruction that caused the fault was a read or write?
+ * @ip: pointer to the instruction that cause the fault
+ *
+ * Note: When CONFIG_KASAN_HW_TAGS is enabled kasan_report() dereferences
+ * the address to access the tags, hence it must be valid at this point in
+ * order to not cause a kernel panic.
+ */
bool kasan_report(unsigned long addr, size_t size, bool is_write,
unsigned long ip)
{
--
2.30.0
