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Date:   Wed, 27 Jan 2021 17:43:22 +0000
From:   Mark Brown <broonie@kernel.org>
To:     Dmitry Vyukov <dvyukov@google.com>
Cc:     syzbot <syzbot+2a52b6c31dbefb1e9d9f@syzkaller.appspotmail.com>,
        amit.kachhap@arm.com, Catalin Marinas <catalin.marinas@arm.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Mark Rutland <mark.rutland@arm.com>, mbenes@suse.cz,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        Will Deacon <will@kernel.org>,
        Andrey Konovalov <andreyknvl@google.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>
Subject: Re: KASAN: invalid-access Read in kmem_cache_destroy
Message-ID: <20210127174322.GH4387@sirena.org.uk>
References: <0000000000008d396205b9e4adee@google.com>
 <CACT4Y+ZisDCO0w9O57tOp+7FL6VqJiFdxaRJ739rjW5z52PeXg@mail.gmail.com>
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On Wed, Jan 27, 2021 at 06:14:13PM +0100, Dmitry Vyukov wrote:
> On Wed, Jan 27, 2021 at 5:58 PM syzbot
> <syzbot+2a52b6c31dbefb1e9d9f@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    2ab38c17 mailmap: remove the "repo-abbrev" comment
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=3D12eb4ad8d00=
000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=3Dad43be24faf=
1194c
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3D2a52b6c31dbef=
b1e9d9f
> > userspace arch: arm64
> >
> > Unfortunately, I don't have any reproducer for this issue yet.
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the co=
mmit:
> > Reported-by: syzbot+2a52b6c31dbefb1e9d9f@syzkaller.appspotmail.com
>=20
> This happens on arm64 instance with MTE enabled.
> I don't see any corresponding reports on x86_64. So I would assume
> it's a generic latent bug, or probably more likely a bug in MTE
> support.

Copying in Vincenso who's done a bunch of MTE stuff recently.

> > loop0: detected capacity change from 131072 to 0
> > F2FS-fs (loop0): Found nat_bits in checkpoint
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > BUG: KASAN: invalid-access in kmem_cache_destroy+0x34/0x174 mm/slab_com=
mon.c:492
> > Read at addr fbff00000cd1ef40 by task syz-executor.0/8859
> > Pointer tag: [fb], memory tag: [fe]
> >
> > CPU: 0 PID: 8859 Comm: syz-executor.0 Not tainted 5.11.0-rc5-syzkaller-=
00037-g2ab38c17aac1 #0
> > Hardware name: linux,dummy-virt (DT)
> > Call trace:
> >  dump_backtrace+0x0/0x1b0 arch/arm64/kernel/stacktrace.c:117
> >  show_stack+0x1c/0x70 arch/arm64/kernel/stacktrace.c:196
> >  __dump_stack lib/dump_stack.c:79 [inline]
> >  dump_stack+0xd0/0x12c lib/dump_stack.c:120
> >  print_address_description+0x70/0x29c mm/kasan/report.c:230
> >  __kasan_report mm/kasan/report.c:396 [inline]
> >  kasan_report+0x104/0x200 mm/kasan/report.c:413
> >  report_tag_fault arch/arm64/mm/fault.c:311 [inline]
> >  do_tag_recovery arch/arm64/mm/fault.c:325 [inline]
> >  __do_kernel_fault+0x17c/0x1c0 arch/arm64/mm/fault.c:369
> >  do_bad_area arch/arm64/mm/fault.c:462 [inline]
> >  do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:717
> >  do_mem_abort+0x44/0xbc arch/arm64/mm/fault.c:793
> >  el1_abort+0x40/0x6c arch/arm64/kernel/entry-common.c:118
> >  el1_sync_handler+0xb0/0xcc arch/arm64/kernel/entry-common.c:209
> >  el1_sync+0x70/0x100 arch/arm64/kernel/entry.S:656
> >  kmem_cache_destroy+0x34/0x174 mm/slab_common.c:492
> >  f2fs_recover_fsync_data+0x60c/0x1cc0 fs/f2fs/recovery.c:869
> >  f2fs_fill_super+0x174c/0x1e8c fs/f2fs/super.c:3804
> >  mount_bdev+0x1c4/0x1f0 fs/super.c:1366
> >  f2fs_mount+0x1c/0x30 fs/f2fs/super.c:3962
> >  legacy_get_tree+0x34/0x64 fs/fs_context.c:592
> >  vfs_get_tree+0x2c/0xf0 fs/super.c:1496
> >  do_new_mount fs/namespace.c:2881 [inline]
> >  path_mount+0x3e8/0xaf0 fs/namespace.c:3211
> >  do_mount fs/namespace.c:3224 [inline]
> >  __do_sys_mount fs/namespace.c:3432 [inline]
> >  __se_sys_mount fs/namespace.c:3409 [inline]
> >  __arm64_sys_mount+0x1a8/0x2fc fs/namespace.c:3409
> >  __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
> >  invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
> >  el0_svc_common.constprop.0+0x74/0x190 arch/arm64/kernel/syscall.c:159
> >  do_el0_svc+0x78/0x90 arch/arm64/kernel/syscall.c:198
> >  el0_svc+0x14/0x20 arch/arm64/kernel/entry-common.c:365
> >  el0_sync_handler+0x1a8/0x1b0 arch/arm64/kernel/entry-common.c:381
> >  el0_sync+0x190/0x1c0 arch/arm64/kernel/entry.S:699
> >
> > Allocated by task 8858:
> >  stack_trace_save+0x50/0x80 kernel/stacktrace.c:121
> >  kasan_save_stack+0x2c/0x60 mm/kasan/common.c:38
> >  kasan_set_track mm/kasan/common.c:46 [inline]
> >  set_alloc_info mm/kasan/common.c:401 [inline]
> >  ____kasan_kmalloc+0xe8/0x160 mm/kasan/common.c:429
> >  __kasan_slab_alloc+0x20/0x30 mm/kasan/common.c:437
> >  kasan_slab_alloc include/linux/kasan.h:209 [inline]
> >  slab_post_alloc_hook mm/slab.h:512 [inline]
> >  slab_alloc_node mm/slub.c:2892 [inline]
> >  slab_alloc mm/slub.c:2900 [inline]
> >  kmem_cache_alloc+0x1b0/0x310 mm/slub.c:2905
> >  kmem_cache_zalloc include/linux/slab.h:672 [inline]
> >  create_cache mm/slab_common.c:246 [inline]
> >  kmem_cache_create_usercopy+0x148/0x2ac mm/slab_common.c:352
> >  kmem_cache_create+0x20/0x30 mm/slab_common.c:410
> >  f2fs_kmem_cache_create fs/f2fs/f2fs.h:2411 [inline]
> >  f2fs_recover_fsync_data+0x7c/0x1cc0 fs/f2fs/recovery.c:790
> >  f2fs_fill_super+0x174c/0x1e8c fs/f2fs/super.c:3804
> >  mount_bdev+0x1c4/0x1f0 fs/super.c:1366
> >  f2fs_mount+0x1c/0x30 fs/f2fs/super.c:3962
> >  legacy_get_tree+0x34/0x64 fs/fs_context.c:592
> >  vfs_get_tree+0x2c/0xf0 fs/super.c:1496
> >  do_new_mount fs/namespace.c:2881 [inline]
> >  path_mount+0x3e8/0xaf0 fs/namespace.c:3211
> >  do_mount fs/namespace.c:3224 [inline]
> >  __do_sys_mount fs/namespace.c:3432 [inline]
> >  __se_sys_mount fs/namespace.c:3409 [inline]
> >  __arm64_sys_mount+0x1a8/0x2fc fs/namespace.c:3409
> >  __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
> >  invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
> >  el0_svc_common.constprop.0+0x74/0x190 arch/arm64/kernel/syscall.c:159
> >  do_el0_svc+0x78/0x90 arch/arm64/kernel/syscall.c:198
> >  el0_svc+0x14/0x20 arch/arm64/kernel/entry-common.c:365
> >  el0_sync_handler+0x1a8/0x1b0 arch/arm64/kernel/entry-common.c:381
> >  el0_sync+0x190/0x1c0 arch/arm64/kernel/entry.S:699
> >
> > Freed by task 8858:
> >  stack_trace_save+0x50/0x80 kernel/stacktrace.c:121
> >  kasan_save_stack+0x2c/0x60 mm/kasan/common.c:38
> >  kasan_set_track+0x2c/0x40 mm/kasan/common.c:46
> >  kasan_set_free_info+0x24/0x30 mm/kasan/hw_tags.c:178
> >  ____kasan_slab_free.constprop.0+0x184/0x1c0 mm/kasan/common.c:362
> >  __kasan_slab_free+0x14/0x20 mm/kasan/common.c:369
> >  kasan_slab_free include/linux/kasan.h:192 [inline]
> >  slab_free_hook mm/slub.c:1547 [inline]
> >  slab_free_freelist_hook+0x9c/0x190 mm/slub.c:1580
> >  slab_free mm/slub.c:3143 [inline]
> >  kmem_cache_free+0xa0/0x460 mm/slub.c:3159
> >  slab_kmem_cache_release+0x34/0x4c mm/slab_common.c:479
> >  kmem_cache_release+0x18/0x24 mm/slub.c:5535
> >  kobject_cleanup lib/kobject.c:705 [inline]
> >  kobject_release lib/kobject.c:736 [inline]
> >  kref_put include/linux/kref.h:65 [inline]
> >  kobject_put+0x74/0x11c lib/kobject.c:753
> >  sysfs_slab_release+0x2c/0x40 mm/slub.c:5659
> >  shutdown_cache mm/slab_common.c:466 [inline]
> >  kmem_cache_destroy+0x134/0x174 mm/slab_common.c:498
> >  f2fs_recover_fsync_data+0x60c/0x1cc0 fs/f2fs/recovery.c:869
> >  f2fs_fill_super+0x174c/0x1e8c fs/f2fs/super.c:3804
> >  mount_bdev+0x1c4/0x1f0 fs/super.c:1366
> >  f2fs_mount+0x1c/0x30 fs/f2fs/super.c:3962
> >  legacy_get_tree+0x34/0x64 fs/fs_context.c:592
> >  vfs_get_tree+0x2c/0xf0 fs/super.c:1496
> >  do_new_mount fs/namespace.c:2881 [inline]
> >  path_mount+0x3e8/0xaf0 fs/namespace.c:3211
> >  do_mount fs/namespace.c:3224 [inline]
> >  __do_sys_mount fs/namespace.c:3432 [inline]
> >  __se_sys_mount fs/namespace.c:3409 [inline]
> >  __arm64_sys_mount+0x1a8/0x2fc fs/namespace.c:3409
> >  __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
> >  invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
> >  el0_svc_common.constprop.0+0x74/0x190 arch/arm64/kernel/syscall.c:159
> >  do_el0_svc+0x78/0x90 arch/arm64/kernel/syscall.c:198
> >  el0_svc+0x14/0x20 arch/arm64/kernel/entry-common.c:365
> >  el0_sync_handler+0x1a8/0x1b0 arch/arm64/kernel/entry-common.c:381
> >  el0_sync+0x190/0x1c0 arch/arm64/kernel/entry.S:699
> >
> > The buggy address belongs to the object at ffff00000cd1ef00
> >  which belongs to the cache kmem_cache of size 216
> > The buggy address is located 64 bytes inside of
> >  216-byte region [ffff00000cd1ef00, ffff00000cd1efd8)
> > The buggy address belongs to the page:
> > page:0000000028de1119 refcount:1 mapcount:0 mapping:0000000000000000 in=
dex:0xf0ff00000cd1ec00 pfn:0x4cd1e
> > flags: 0x1ffffc000000200(slab)
> > raw: 01ffffc000000200 dead000000000100 dead000000000122 f1ff000004001000
> > raw: f0ff00000cd1ec00 000000008010000a 00000001ffffffff 0000000000000000
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> >  ffff00000cd1ed00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
> >  ffff00000cd1ee00: f0 f0 f0 f0 f0 f0 f0 f0 f0 f0 f0 f0 f0 f0 fe fe
> > >ffff00000cd1ef00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
> >                                ^
> >  ffff00000cd1f000: f4 f4 f4 f4 fe fe fe fe f9 f9 f9 f9 fe fe fe fe
> >  ffff00000cd1f100: f9 f9 f9 f9 fe fe fe fe f1 f1 f1 f1 fe fe fe fe
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> >
> >
> > ---
> > This report is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@googlegroups.com.
> >
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > --
> > You received this message because you are subscribed to the Google Grou=
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> > To view this discussion on the web visit https://groups.google.com/d/ms=
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