[PATCH v2 2/2] kasan: Add explicit preconditions to kasan_report()
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
Date: 2021-01-21 13:23:06
Also in:
lkml
Subsystem:
kasan, memory management, the rest · Maintainers:
Andrey Ryabinin, Andrew Morton, Linus Torvalds
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) passed to the function when, KASAN_HW_TAGS is enabled, leads to a kernel panic. Cc: Andrey Ryabinin <redacted> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Leon Romanovsky <redacted> Cc: Andrey Konovalov <redacted> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- mm/kasan/kasan.h | 2 +- mm/kasan/report.c | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index cc4d9e1d49b1..8c706e7652f2 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h@@ -209,7 +209,7 @@ bool check_memory_region(unsigned long addr, size_t size, bool write, static inline bool addr_has_metadata(const void *addr) { - return true; + return (is_vmalloc_addr(addr) || virt_addr_valid(addr)); } #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index c0fb21797550..8b690091cb37 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c@@ -403,6 +403,13 @@ 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 + */ bool kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip) {
--
2.30.0
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