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Yu Kuai 077a403354 block: don't allow a disk link holder to itself
After creating a dm device, then user can reload such dm with itself,
and dead loop will be triggered because dm keep looking up to itself.

Test procedures:

1) dmsetup create test --table "xxx sda", assume dm-0 is created
2) dmsetup suspend test
3) dmsetup reload test --table "xxx dm-0"
4) dmsetup resume test

Test result:

BUG: TASK stack guard page was hit at 00000000736a261f (stack is 000000008d12c88d..00000000c8dd82d5)
stack guard page: 0000 [#1] PREEMPT SMP
CPU: 29 PID: 946 Comm: systemd-udevd Not tainted 6.1.0-rc3-next-20221101-00006-g17640ca3b0ee #1295
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
RIP: 0010:dm_prepare_ioctl+0xf/0x1e0
Code: da 48 83 05 4a 7c 99 0b 01 41 89 c4 eb cd e8 b8 1f 40 00 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 48 83 05 a1 5a 99 0b 01 <41> 56 49 89 d6 41 55 4c 8d af 90 02 00 00 9
RSP: 0018:ffffc90002090000 EFLAGS: 00010206
RAX: ffff8881049d6800 RBX: ffff88817e589000 RCX: 0000000000000000
RDX: ffffc90002090010 RSI: ffffc9000209001c RDI: ffff88817e589000
RBP: 00000000484a101d R08: 0000000000000000 R09: 0000000000000007
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000005331
R13: 0000000000005331 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fddf9609200(0000) GS:ffff889fbfd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc9000208fff8 CR3: 0000000179043000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dm_blk_ioctl+0x50/0x1c0
 ? dm_prepare_ioctl+0xe0/0x1e0
 dm_blk_ioctl+0x88/0x1c0
 dm_blk_ioctl+0x88/0x1c0
 ......(a lot of same lines)
 dm_blk_ioctl+0x88/0x1c0
 dm_blk_ioctl+0x88/0x1c0
 blkdev_ioctl+0x184/0x3e0
 __x64_sys_ioctl+0xa3/0x110
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fddf7306577
Code: b3 66 90 48 8b 05 11 89 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 88 8
RSP: 002b:00007ffd0b2ec318 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00005634ef478320 RCX: 00007fddf7306577
RDX: 0000000000000000 RSI: 0000000000005331 RDI: 0000000000000007
RBP: 0000000000000007 R08: 00005634ef4843e0 R09: 0000000000000080
R10: 00007fddf75cfb38 R11: 0000000000000246 R12: 00000000030d4000
R13: 0000000000000000 R14: 0000000000000000 R15: 00005634ef48b800
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dm_prepare_ioctl+0xf/0x1e0
Code: da 48 83 05 4a 7c 99 0b 01 41 89 c4 eb cd e8 b8 1f 40 00 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 48 83 05 a1 5a 99 0b 01 <41> 56 49 89 d6 41 55 4c 8d af 90 02 00 00 9
RSP: 0018:ffffc90002090000 EFLAGS: 00010206
RAX: ffff8881049d6800 RBX: ffff88817e589000 RCX: 0000000000000000
RDX: ffffc90002090010 RSI: ffffc9000209001c RDI: ffff88817e589000
RBP: 00000000484a101d R08: 0000000000000000 R09: 0000000000000007
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000005331
R13: 0000000000005331 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fddf9609200(0000) GS:ffff889fbfd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc9000208fff8 CR3: 0000000179043000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fix the problem by forbidding a disk to create link to itself.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221115141054.1051801-11-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-16 15:19:56 -07:00
arch RISC-V: 2022-10-23 15:00:43 -07:00
block block: don't allow a disk link holder to itself 2022-11-16 15:19:56 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
Documentation ABI: sysfs-bus-pci: add documentation for p2pmem allocate 2022-11-09 11:29:21 -07:00
drivers dm: track per-add_disk holder relations in DM 2022-11-16 15:19:56 -07:00
fs First batch of EFI fixes for v6.1 2022-10-21 18:02:36 -07:00
include block: remove delayed holder registration 2022-11-16 15:19:56 -07:00
init init: Kconfig: fix spelling mistake "satify" -> "satisfy" 2022-10-20 21:27:22 -07:00
io_uring io_uring/rw: enable bio caches for IRQ rw 2022-11-16 09:44:27 -07:00
ipc - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
kernel wait: Return number of exclusive waiters awaken 2022-11-16 11:33:03 -07:00
lib sbitmap: Try each queue to wake up at least one waiter 2022-11-16 11:33:03 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: introduce FOLL_PCI_P2PDMA to gate getting PCI P2PDMA pages 2022-11-09 11:29:20 -07:00
net io_uring-6.1-2022-10-22 2022-10-23 09:55:50 -07:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
scripts Kbuild fixes for v6.1 2022-10-16 11:12:22 -07:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
sound sound fixes for 6.1-rc1 2022-10-14 13:22:14 -07:00
tools RISC-V: 2022-10-23 15:00:43 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm: Add support for arch compat vm ioctls 2022-10-22 05:15:23 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap mailmap: update email for Qais Yousef 2022-10-20 21:27:21 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS pci-v6.1-fixes-2 2022-10-22 15:52:36 -07:00
Makefile Linux 6.1-rc2 2022-10-23 15:27:33 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.