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authorAndrey Konovalov <andreyknvl@google.com>2022-03-25 04:11:04 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-25 05:06:47 +0300
commit4aff1dc4fb3a5a3be96b6ad8db8348d3e877d7d0 (patch)
tree209e2448248bedcaef370b432b72cbb68989dbf6 /mm/vmalloc.c
parent579fb0ac085be2015529a5f7bd1061899a6374de (diff)
downloadlinux-4aff1dc4fb3a5a3be96b6ad8db8348d3e877d7d0.tar.xz
kasan, vmalloc: reset tags in vmalloc functions
In preparation for adding vmalloc support to SW/HW_TAGS KASAN, reset pointer tags in functions that use pointer values in range checks. vread() is a special case here. Despite the untagging of the addr pointer in its prologue, the accesses performed by vread() are checked. Instead of accessing the virtual mappings though addr directly, vread() recovers the physical address via page_address(vmalloc_to_page()) and acceses that. And as page_address() recovers the pointer tag, the accesses get checked. Link: https://lkml.kernel.org/r/046003c5f683cacb0ba18e1079e9688bb3dca943.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index feecd614bb77..ab0a0002bfca 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -74,7 +74,7 @@ static const bool vmap_allow_huge = false;
bool is_vmalloc_addr(const void *x)
{
- unsigned long addr = (unsigned long)x;
+ unsigned long addr = (unsigned long)kasan_reset_tag(x);
return addr >= VMALLOC_START && addr < VMALLOC_END;
}
@@ -631,7 +631,7 @@ int is_vmalloc_or_module_addr(const void *x)
* just put it in the vmalloc space.
*/
#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
- unsigned long addr = (unsigned long)x;
+ unsigned long addr = (unsigned long)kasan_reset_tag(x);
if (addr >= MODULES_VADDR && addr < MODULES_END)
return 1;
#endif
@@ -795,6 +795,8 @@ static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
struct vmap_area *va = NULL;
struct rb_node *n = vmap_area_root.rb_node;
+ addr = (unsigned long)kasan_reset_tag((void *)addr);
+
while (n) {
struct vmap_area *tmp;
@@ -816,6 +818,8 @@ static struct vmap_area *__find_vmap_area(unsigned long addr)
{
struct rb_node *n = vmap_area_root.rb_node;
+ addr = (unsigned long)kasan_reset_tag((void *)addr);
+
while (n) {
struct vmap_area *va;
@@ -2166,7 +2170,7 @@ EXPORT_SYMBOL_GPL(vm_unmap_aliases);
void vm_unmap_ram(const void *mem, unsigned int count)
{
unsigned long size = (unsigned long)count << PAGE_SHIFT;
- unsigned long addr = (unsigned long)mem;
+ unsigned long addr = (unsigned long)kasan_reset_tag(mem);
struct vmap_area *va;
might_sleep();
@@ -3424,6 +3428,8 @@ long vread(char *buf, char *addr, unsigned long count)
unsigned long buflen = count;
unsigned long n;
+ addr = kasan_reset_tag(addr);
+
/* Don't allow overflow */
if ((unsigned long) addr + count < count)
count = -(unsigned long) addr;