| Message ID | 20210121131956.23246-3-vincenzo.frascino@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kasan: Fix metadata detection for KASAN_HW_TAGS | expand |
On Thu, Jan 21, 2021 at 2:20 PM Vincenzo Frascino <vincenzo.frascino@arm.com> wrote: > > 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 <aryabinin@virtuozzo.com> > Cc: Alexander Potapenko <glider@google.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Leon Romanovsky <leonro@mellanox.com> > Cc: Andrey Konovalov <andreyknvl@google.com> > 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 print a report about a bad memory access detected by KASAN > + * @addr: valid address of the allocation where the tag fault was detected address of the bad access > + * @size: size of the allocation where the tag fault was detected size of the bad access > + * @is_write: the instruction that caused the fault was a read or write? whether the bad access is a write or a read (no question mark at the end) > + * @ip: pointer to the instruction that cause the fault instruction pointer for the accessibility check or the bad access itself > + */ And please move this to include/kasan/kasan.h. > bool kasan_report(unsigned long addr, size_t size, bool is_write, > unsigned long ip) > { > -- > 2.30.0 >
Hi Andrey,
All done. Reposting shortly. Thank you!
On 1/21/21 5:20 PM, Andrey Konovalov wrote:
> And please move this to include/kasan/kasan.h.
I guess you meant include/linux/kasan.h.
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) {
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 <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Andrey Konovalov <andreyknvl@google.com> 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(-)