• Kuan-Ying Lee's avatar
    mm/kmemleak: reset tag when compare object pointer · bfc8089f
    Kuan-Ying Lee authored
    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.
    
      kmemleak: [name:kmemleak&]Scan area larger than object 0xffffffe77076f440
      CPU: 4 PID: 1 Comm: init Tainted: G S      W         5.15.25-android13-0-g5cacf919c2bc #1
      Hardware name: MT6983(ENG) (DT)
      Call trace:
       add_scan_area+0xc4/0x244
       kmemleak_scan_area+0x40/0x9c
       layout_and_allocate+0x1e8/0x288
       load_module+0x2c8/0xf00
       __se_sys_finit_module+0x190/0x1d0
       __arm64_sys_finit_module+0x20/0x30
       invoke_syscall+0x60/0x170
       el0_svc_common+0xc8/0x114
       do_el0_svc+0x28/0xa0
       el0_svc+0x60/0xf8
       el0t_64_sync_handler+0x88/0xec
       el0t_64_sync+0x1b4/0x1b8
      kmemleak: [name:kmemleak&]Object 0xf5ffffe77076b000 (size 32768):
      kmemleak: [name:kmemleak&]  comm "init", pid 1, jiffies 4294894197
      kmemleak: [name:kmemleak&]  min_count = 0
      kmemleak: [name:kmemleak&]  count = 0
      kmemleak: [name:kmemleak&]  flags = 0x1
      kmemleak: [name:kmemleak&]  checksum = 0
      kmemleak: [name:kmemleak&]  backtrace:
           module_alloc+0x9c/0x120
           move_module+0x34/0x19c
           layout_and_allocate+0x1c4/0x288
           load_module+0x2c8/0xf00
           __se_sys_finit_module+0x190/0x1d0
           __arm64_sys_finit_module+0x20/0x30
           invoke_syscall+0x60/0x170
           el0_svc_common+0xc8/0x114
           do_el0_svc+0x28/0xa0
           el0_svc+0x60/0xf8
           el0t_64_sync_handler+0x88/0xec
           el0t_64_sync+0x1b4/0x1b8
    
    Link: https://lkml.kernel.org/r/20220318034051.30687-1-Kuan-Ying.Lee@mediatek.comSigned-off-by: default avatarKuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
    Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    Cc: Matthias Brugger <matthias.bgg@gmail.com>
    Cc: Chinwen Chang <chinwen.chang@mediatek.com>
    Cc: Nicholas Tang <nicholas.tang@mediatek.com>
    Cc: Yee Lee <yee.lee@mediatek.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    bfc8089f
kmemleak.c 57 KB