Messages in this thread | | | From | Andrey Konovalov <> | Date | Fri, 18 Feb 2022 16:07:58 +0100 | Subject | Re: [PATCH mm] kasan: print virtual mapping info in reports |
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On Thu, Feb 17, 2022 at 1:00 PM Mark Rutland <mark.rutland@arm.com> wrote: > > On Wed, Feb 16, 2022 at 08:01:37PM +0100, andrey.konovalov@linux.dev wrote: > > From: Andrey Konovalov <andreyknvl@google.com> > > > > Print virtual mapping range and its creator in reports affecting virtual > > mappings. > > > > Also get physical page pointer for such mappings, so page information > > gets printed as well. > > > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > > > > --- > > > > Note: no need to merge this patch into any of the KASAN vmalloc patches > > that are already in mm, better to keep it separate. > > --- > > mm/kasan/report.c | 12 +++++++++++- > > 1 file changed, 11 insertions(+), 1 deletion(-) > > > > diff --git a/mm/kasan/report.c b/mm/kasan/report.c > > index 137c2c0b09db..8002fb3c417d 100644 > > --- a/mm/kasan/report.c > > +++ b/mm/kasan/report.c > > @@ -260,8 +260,18 @@ static void print_address_description(void *addr, u8 tag) > > pr_err(" %pS\n", addr); > > } > > > > + if (is_vmalloc_addr(addr)) { > > + struct vm_struct *va = find_vm_area(addr); > > + > > + pr_err("The buggy address belongs to the virtual mapping at\n" > > + " [%px, %px) created by:\n" > > + " %pS\n", va->addr, va->addr + va->size, va->caller); > > The return value of find_vm_area() needs a NULL check here; > is_vmalloc_addr(addr) just checks that `addr` is within the vmalloc VA > range, and doesn't guarantee that there is a vmap_area associated with > that `addr`. > > Without the NULL-check, we'll blow up on the `va->addr` dereference and > will fail to make the report, which would be unfortunate.
Indeed. Will fix in v2. Thanks, Mark!
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