| Message ID | 20220318034051.30687-1-Kuan-Ying.Lee@mediatek.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/kmemleak: Reset tag when compare object pointer | expand |
On Fri, Mar 18, 2022 at 11:40:48AM +0800, Kuan-Ying Lee wrote: > When we use HW-tag based kasan and enable vmalloc support, we hit > the following bug. It is due to comparison between tagged object > and non-tagged pointer. > > We need to reset the kasan tag when we need to compare tagged object > and non-tagged pointer. > > [ 7.690429][T400001] init: kmemleak: [name:kmemleak&]Scan area larger than object 0xffffffe77076f440 > [ 7.691762][T400001] init: CPU: 4 PID: 1 Comm: init Tainted: G S W 5.15.25-android13-0-g5cacf919c2bc #1 > [ 7.693218][T400001] init: Hardware name: MT6983(ENG) (DT) > [ 7.693983][T400001] init: Call trace: > [ 7.694508][T400001] init: dump_backtrace.cfi_jt+0x0/0x8 > [ 7.695272][T400001] init: dump_stack_lvl+0xac/0x120 > [ 7.695985][T400001] init: add_scan_area+0xc4/0x244 > [ 7.696685][T400001] init: kmemleak_scan_area+0x40/0x9c > [ 7.697428][T400001] init: layout_and_allocate+0x1e8/0x288 > [ 7.698211][T400001] init: load_module+0x2c8/0xf00 > [ 7.698895][T400001] init: __se_sys_finit_module+0x190/0x1d0 > [ 7.699701][T400001] init: __arm64_sys_finit_module+0x20/0x30 > [ 7.700517][T400001] init: invoke_syscall+0x60/0x170 > [ 7.701225][T400001] init: el0_svc_common+0xc8/0x114 > [ 7.701933][T400001] init: do_el0_svc+0x28/0xa0 > [ 7.702580][T400001] init: el0_svc+0x60/0xf8 > [ 7.703196][T400001] init: el0t_64_sync_handler+0x88/0xec > [ 7.703964][T400001] init: el0t_64_sync+0x1b4/0x1b8 > [ 7.704658][T400001] init: kmemleak: [name:kmemleak&]Object 0xf5ffffe77076b000 (size 32768): > [ 7.705824][T400001] init: kmemleak: [name:kmemleak&] comm "init", pid 1, jiffies 4294894197 > [ 7.707002][T400001] init: kmemleak: [name:kmemleak&] min_count = 0 > [ 7.707886][T400001] init: kmemleak: [name:kmemleak&] count = 0 > [ 7.708718][T400001] init: kmemleak: [name:kmemleak&] flags = 0x1 > [ 7.709574][T400001] init: kmemleak: [name:kmemleak&] checksum = 0 > [ 7.710440][T400001] init: kmemleak: [name:kmemleak&] backtrace: > [ 7.711284][T400001] init: module_alloc+0x9c/0x120 > [ 7.712015][T400001] init: move_module+0x34/0x19c > [ 7.712735][T400001] init: layout_and_allocate+0x1c4/0x288 > [ 7.713561][T400001] init: load_module+0x2c8/0xf00 > [ 7.714291][T400001] init: __se_sys_finit_module+0x190/0x1d0 > [ 7.715142][T400001] init: __arm64_sys_finit_module+0x20/0x30 > [ 7.716004][T400001] init: invoke_syscall+0x60/0x170 > [ 7.716758][T400001] init: el0_svc_common+0xc8/0x114 > [ 7.717512][T400001] init: do_el0_svc+0x28/0xa0 > [ 7.718207][T400001] init: el0_svc+0x60/0xf8 > [ 7.718869][T400001] init: el0t_64_sync_handler+0x88/0xec > [ 7.719683][T400001] init: el0t_64_sync+0x1b4/0x1b8 > > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 7580baa76af1..acd7cbb82e16 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -796,6 +796,8 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp) unsigned long flags; struct kmemleak_object *object; struct kmemleak_scan_area *area = NULL; + unsigned long untagged_ptr; + unsigned long untagged_objp; object = find_and_get_object(ptr, 1); if (!object) { @@ -804,6 +806,9 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp) return; } + untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr); + untagged_objp = (unsigned long)kasan_reset_tag((void *)object->pointer); + if (scan_area_cache) area = kmem_cache_alloc(scan_area_cache, gfp_kmemleak_mask(gfp)); @@ -815,8 +820,8 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp) goto out_unlock; } if (size == SIZE_MAX) { - size = object->pointer + object->size - ptr; - } else if (ptr + size > object->pointer + object->size) { + size = untagged_objp + object->size - untagged_ptr; + } else if (untagged_ptr + size > untagged_objp + object->size) { kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr); dump_object_info(object); kmem_cache_free(scan_area_cache, area);
When we use HW-tag based kasan and enable vmalloc support, we hit the following bug. It is due to comparison between tagged object and non-tagged pointer. We need to reset the kasan tag when we need to compare tagged object and non-tagged pointer. [ 7.690429][T400001] init: kmemleak: [name:kmemleak&]Scan area larger than object 0xffffffe77076f440 [ 7.691762][T400001] init: CPU: 4 PID: 1 Comm: init Tainted: G S W 5.15.25-android13-0-g5cacf919c2bc #1 [ 7.693218][T400001] init: Hardware name: MT6983(ENG) (DT) [ 7.693983][T400001] init: Call trace: [ 7.694508][T400001] init: dump_backtrace.cfi_jt+0x0/0x8 [ 7.695272][T400001] init: dump_stack_lvl+0xac/0x120 [ 7.695985][T400001] init: add_scan_area+0xc4/0x244 [ 7.696685][T400001] init: kmemleak_scan_area+0x40/0x9c [ 7.697428][T400001] init: layout_and_allocate+0x1e8/0x288 [ 7.698211][T400001] init: load_module+0x2c8/0xf00 [ 7.698895][T400001] init: __se_sys_finit_module+0x190/0x1d0 [ 7.699701][T400001] init: __arm64_sys_finit_module+0x20/0x30 [ 7.700517][T400001] init: invoke_syscall+0x60/0x170 [ 7.701225][T400001] init: el0_svc_common+0xc8/0x114 [ 7.701933][T400001] init: do_el0_svc+0x28/0xa0 [ 7.702580][T400001] init: el0_svc+0x60/0xf8 [ 7.703196][T400001] init: el0t_64_sync_handler+0x88/0xec [ 7.703964][T400001] init: el0t_64_sync+0x1b4/0x1b8 [ 7.704658][T400001] init: kmemleak: [name:kmemleak&]Object 0xf5ffffe77076b000 (size 32768): [ 7.705824][T400001] init: kmemleak: [name:kmemleak&] comm "init", pid 1, jiffies 4294894197 [ 7.707002][T400001] init: kmemleak: [name:kmemleak&] min_count = 0 [ 7.707886][T400001] init: kmemleak: [name:kmemleak&] count = 0 [ 7.708718][T400001] init: kmemleak: [name:kmemleak&] flags = 0x1 [ 7.709574][T400001] init: kmemleak: [name:kmemleak&] checksum = 0 [ 7.710440][T400001] init: kmemleak: [name:kmemleak&] backtrace: [ 7.711284][T400001] init: module_alloc+0x9c/0x120 [ 7.712015][T400001] init: move_module+0x34/0x19c [ 7.712735][T400001] init: layout_and_allocate+0x1c4/0x288 [ 7.713561][T400001] init: load_module+0x2c8/0xf00 [ 7.714291][T400001] init: __se_sys_finit_module+0x190/0x1d0 [ 7.715142][T400001] init: __arm64_sys_finit_module+0x20/0x30 [ 7.716004][T400001] init: invoke_syscall+0x60/0x170 [ 7.716758][T400001] init: el0_svc_common+0xc8/0x114 [ 7.717512][T400001] init: do_el0_svc+0x28/0xa0 [ 7.718207][T400001] init: el0_svc+0x60/0xf8 [ 7.718869][T400001] init: el0t_64_sync_handler+0x88/0xec [ 7.719683][T400001] init: el0t_64_sync+0x1b4/0x1b8 Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> --- mm/kmemleak.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)