mm/kmemleak: reset tag when compare object pointer
Subsystems (3)
Andrew Morton
maintainerPATCH 15/16 mm/kmemleak: reset tag when compare object pointer
From: Kuan-Ying Lee <[email protected]>
Subject: mm/kmemleak: reset tag when compare object pointer
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 <[email protected]>
Reviewed-by Catalin Marinas <[email protected]>
Cc Matthias Brugger <[email protected]>
Cc Chinwen Chang <[email protected]>
Cc Nicholas Tang <[email protected]>
Cc Yee Lee <[email protected]>
Cc <[email protected]>
Signed-off-by Andrew Morton <[email protected]>
---
mm/kmemleak.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
mm/kmemleak.c renamed from mm/kmemleak.c~mm-kmemleak-reset-tag-when-compare-object-pointer +7 -2
@@ -796,6 +796,8 @@ static void add_scan_area(unsigned longunsigned 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 longreturn ; } + 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 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);
_