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From: Aleksandr Nogikh <nogikh@google.com>
Date: Fri, 3 May 2024 14:34:30 +0200
Message-ID: <CANp29Y5k1S5ETBibTzWv7y6jiKevOhMYg0LYqM+PGvuFYiM14A@mail.gmail.com>
Subject: Re: [syzbot] [crypto?] KMSAN: uninit-value in skcipher_walk_virt
To: syzbot <syzbot+97b4444a5bd7bf30b3a8@syzkaller.appspotmail.com>, 
	Kent Overstreet <kent.overstreet@linux.dev>
Cc: davem@davemloft.net, herbert@gondor.apana.org.au, 
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com
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#syz set subsystems: bcachefs

On Fri, May 3, 2024 at 2:24=E2=80=AFPM syzbot
<syzbot+97b4444a5bd7bf30b3a8@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    f03359bca01b Merge tag 'for-6.9-rc6-tag' of git://git.ker=
n..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=3D17c169df18000=
0
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3Dbbf5674960220=
57b
> dashboard link: https://syzkaller.appspot.com/bug?extid=3D97b4444a5bd7bf3=
0b3a8
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Deb=
ian) 2.40
> userspace arch: i386
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/b345b1c01095/dis=
k-f03359bc.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/d59970ea319e/vmlinu=
x-f03359bc.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/47407f406f40/b=
zImage-f03359bc.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the comm=
it:
> Reported-by: syzbot+97b4444a5bd7bf30b3a8@syzkaller.appspotmail.com
>
> loop3: detected capacity change from 0 to 32768
> bcachefs (loop3): mounting version 1.7: mi_btree_bitmap opts=3Dmetadata_c=
hecksum=3Dnone,data_checksum=3Dnone,nojournal_transaction_names
> bcachefs (loop3): recovering from clean shutdown, journal seq 10
> =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: KMSAN: uninit-value in skcipher_walk_virt+0x91/0x1a0 crypto/skcipher=
.c:504
>  skcipher_walk_virt+0x91/0x1a0 crypto/skcipher.c:504
>  chacha_stream_xor+0x7c/0x710 crypto/chacha_generic.c:22
>  crypto_chacha_crypt+0x79/0xb0 crypto/chacha_generic.c:45
>  crypto_skcipher_encrypt+0x1a0/0x1e0 crypto/skcipher.c:671
>  do_encrypt_sg fs/bcachefs/checksum.c:107 [inline]
>  do_encrypt+0x99c/0xc30 fs/bcachefs/checksum.c:127
>  gen_poly_key fs/bcachefs/checksum.c:190 [inline]
>  bch2_checksum+0x21f/0x7c0 fs/bcachefs/checksum.c:226
>  bch2_btree_node_read_done+0x1898/0x75e0 fs/bcachefs/btree_io.c:1055
>  btree_node_read_work+0x8a5/0x1eb0 fs/bcachefs/btree_io.c:1324
>  bch2_btree_node_read+0x3d42/0x4b50
>  __bch2_btree_root_read fs/bcachefs/btree_io.c:1748 [inline]
>  bch2_btree_root_read+0xa6c/0x13d0 fs/bcachefs/btree_io.c:1772
>  read_btree_roots+0x454/0xee0 fs/bcachefs/recovery.c:457
>  bch2_fs_recovery+0x7adb/0x9310 fs/bcachefs/recovery.c:785
>  bch2_fs_start+0x7b2/0xbd0 fs/bcachefs/super.c:1043
>  bch2_fs_open+0x135f/0x1670 fs/bcachefs/super.c:2102
>  bch2_mount+0x90d/0x1d90 fs/bcachefs/fs.c:1903
>  legacy_get_tree+0x114/0x290 fs/fs_context.c:662
>  vfs_get_tree+0xa7/0x570 fs/super.c:1779
>  do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
>  path_mount+0x742/0x1f20 fs/namespace.c:3679
>  do_mount fs/namespace.c:3692 [inline]
>  __do_sys_mount fs/namespace.c:3898 [inline]
>  __se_sys_mount+0x725/0x810 fs/namespace.c:3875
>  __ia32_sys_mount+0xe3/0x150 fs/namespace.c:3875
>  ia32_sys_call+0x3a9a/0x40a0 arch/x86/include/generated/asm/syscalls_32.h=
:22
>  do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
>  __do_fast_syscall_32+0xb4/0x120 arch/x86/entry/common.c:386
>  do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
>  do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
>  entry_SYSENTER_compat_after_hwframe+0x84/0x8e
>
> Local variable __req_desc.i created at:
>  do_encrypt_sg fs/bcachefs/checksum.c:101 [inline]
>  do_encrypt+0x8f9/0xc30 fs/bcachefs/checksum.c:127
>  gen_poly_key fs/bcachefs/checksum.c:190 [inline]
>  bch2_checksum+0x21f/0x7c0 fs/bcachefs/checksum.c:226
>
> CPU: 1 PID: 15218 Comm: syz-executor.3 Not tainted 6.9.0-rc6-syzkaller-00=
131-gf03359bca01b #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS G=
oogle 03/27/2024
> =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.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>
> --
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