mm: defer kmemleak object creation of module_alloc()
authorKefeng Wang <wangkefeng.wang@huawei.com>
Fri, 14 Jan 2022 22:04:11 +0000 (14:04 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 15 Jan 2022 14:30:25 +0000 (16:30 +0200)
commit60115fa54ad7b913b7cb5844e6b7ffeb842d55f2
tree4ede7759696d4377bf92a084f54024b61a5fdc82
parent972fa3a7c17c9d60212e32ecc0205dc585b1e769
mm: defer kmemleak object creation of module_alloc()

Yongqiang reports a kmemleak panic when module insmod/rmmod with KASAN
enabled(without KASAN_VMALLOC) on x86[1].

When the module area allocates memory, it's kmemleak_object is created
successfully, but the KASAN shadow memory of module allocation is not
ready, so when kmemleak scan the module's pointer, it will panic due to
no shadow memory with KASAN check.

  module_alloc
    __vmalloc_node_range
      kmemleak_vmalloc
kmemleak_scan
  update_checksum
    kasan_module_alloc
      kmemleak_ignore

Note, there is no problem if KASAN_VMALLOC enabled, the modules area
entire shadow memory is preallocated.  Thus, the bug only exits on ARCH
which supports dynamic allocation of module area per module load, for
now, only x86/arm64/s390 are involved.

Add a VM_DEFER_KMEMLEAK flags, defer vmalloc'ed object register of
kmemleak in module_alloc() to fix this issue.

[1] https://lore.kernel.org/all/6d41e2b9-4692-5ec4-b1cd-cbe29ae89739@huawei.com/

[wangkefeng.wang@huawei.com: fix build]
Link: https://lkml.kernel.org/r/20211125080307.27225-1-wangkefeng.wang@huawei.com
[akpm@linux-foundation.org: simplify ifdefs, per Andrey]
Link: https://lkml.kernel.org/r/CA+fCnZcnwJHUQq34VuRxpdoY6_XbJCDJ-jopksS5Eia4PijPzw@mail.gmail.com
Link: https://lkml.kernel.org/r/20211124142034.192078-1-wangkefeng.wang@huawei.com
Fixes: 793213a82de4 ("s390/kasan: dynamic shadow mem allocation for modules")
Fixes: 39d114ddc682 ("arm64: add KASAN support")
Fixes: bebf56a1b176 ("kasan: enable instrumentation of global variables")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reported-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/arm64/kernel/module.c
arch/s390/kernel/module.c
arch/x86/kernel/module.c
include/linux/kasan.h
include/linux/vmalloc.h
mm/kasan/shadow.c
mm/vmalloc.c