Re: [syzbot] [arm?] [crypto?] KASAN: invalid-access Read in neon_aes_ctr_encrypt

[Ard Biesheuvel]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git
neon-aes-ctr-fix

On Sat, 17 Feb 2024 at 02:35, syzbot
<syzbot+f1ceaa1a09ab891e1934@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    c664e16bb1ba Merge tag 'docs-6.8-fixes2' of git://git.lwn...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13e83cc8180000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=b4dde08ba7d52a4b
> dashboard link: https://syzkaller.appspot.com/bug?extid=f1ceaa1a09ab891e1934
> compiler:       aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> userspace arch: arm64
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13fff792180000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15cbe4dc180000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-c664e16b.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/864da5a66121/vmlinux-c664e16b.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/044de3e4ddc5/Image-c664e16b.gz.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+f1ceaa1a09ab891e1934@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ==================================================================
> BUG: KASAN: invalid-access in neon_aes_ctr_encrypt+0x15c/0x1ec arch/arm64/crypto/aes-modes.S:599
> Read at addr fcff000006797ff1 by task syz-executor675/3149
> Pointer tag: [fc], memory tag: [fe]
>
> CPU: 1 PID: 3149 Comm: syz-executor675 Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0
> Hardware name: linux,dummy-virt (DT)
> Call trace:
>  dump_backtrace+0x94/0xec arch/arm64/kernel/stacktrace.c:291
>  show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:298
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0x48/0x60 lib/dump_stack.c:106
>  print_address_description mm/kasan/report.c:377 [inline]
>  print_report+0x108/0x618 mm/kasan/report.c:488
>  kasan_report+0x88/0xac mm/kasan/report.c:601
>  report_tag_fault arch/arm64/mm/fault.c:334 [inline]
>  do_tag_recovery arch/arm64/mm/fault.c:346 [inline]
>  __do_kernel_fault+0x17c/0x1e8 arch/arm64/mm/fault.c:393
>  do_bad_area arch/arm64/mm/fault.c:493 [inline]
>  do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:772
>  do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:848
>  el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:398
>  el1h_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:458
>  el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:593
>  neon_aes_ctr_encrypt+0x15c/0x1ec arch/arm64/crypto/aes-modes.S:599
>  ctr_encrypt+0xfc/0x144 arch/arm64/crypto/aes-neonbs-glue.c:230
>  crypto_skcipher_decrypt+0x4c/0x60 crypto/skcipher.c:695
>  _skcipher_recvmsg crypto/algif_skcipher.c:199 [inline]
>  skcipher_recvmsg+0x39c/0x46c crypto/algif_skcipher.c:221
>  sock_recvmsg_nosec net/socket.c:1046 [inline]
>  sock_recvmsg net/socket.c:1068 [inline]
>  sock_recvmsg net/socket.c:1064 [inline]
>  sock_read_iter+0xec/0x118 net/socket.c:1138
>  call_read_iter include/linux/fs.h:2079 [inline]
>  new_sync_read fs/read_write.c:395 [inline]
>  vfs_read+0x2cc/0x304 fs/read_write.c:476
>  ksys_read+0xe8/0x104 fs/read_write.c:619
>  __do_sys_read fs/read_write.c:629 [inline]
>  __se_sys_read fs/read_write.c:627 [inline]
>  __arm64_sys_read+0x1c/0x28 fs/read_write.c:627
>  __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
>  invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:51
>  el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:136
>  do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:155
>  el0_svc+0x34/0xd8 arch/arm64/kernel/entry-common.c:678
>  el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:696
>  el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598
>
> The buggy address belongs to the physical page:
> page:0000000060acabc6 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x46797
> flags: 0x1ffc28000000000(node=0|zone=0|lastcpupid=0x7ff|kasantag=0xa)
> page_type: 0xffffffff()
> raw: 01ffc28000000000 fffffc0000168bc8 fffffc0000199e08 0000000000000000
> raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>  ffff000006797d00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
>  ffff000006797e00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
> >ffff000006797f00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
>                                                                 ^
>  ffff000006798000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>  ffff000006798100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ==================================================================
>
>
> ---
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