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Ryusuke Konishi 610a2a3d7d nilfs2: fix shift-out-of-bounds/overflow in nilfs_sb2_bad_offset()
Patch series "nilfs2: fix UBSAN shift-out-of-bounds warnings on mount
time".

The first patch fixes a bug reported by syzbot, and the second one fixes
the remaining bug of the same kind.  Although they are triggered by the
same super block data anomaly, I divided it into the above two because the
details of the issues and how to fix it are different.

Both are required to eliminate the shift-out-of-bounds issues at mount
time.


This patch (of 2):

If the block size exponent information written in an on-disk superblock is
corrupted, nilfs_sb2_bad_offset helper function can trigger
shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn
is set):

 shift exponent 38983 is too large for 64-bit type 'unsigned long long'
 Call Trace:
  <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
  ubsan_epilogue lib/ubsan.c:151 [inline]
  __ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322
  nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline]
  nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523
  init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577
  nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047
  nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317
  ...

In addition, since nilfs_sb2_bad_offset() performs multiplication without
considering the upper bound, the computation may overflow if the disk
layout parameters are not normal.

This fixes these issues by inserting preliminary sanity checks for those
parameters and by converting the comparison from one involving
multiplication and left bit-shifting to one using division and right
bit-shifting.

Link: https://lkml.kernel.org/r/20221027044306.42774-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20221027044306.42774-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+e91619dd4c11c4960706@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-18 13:55:08 -08:00
arch ia64: remove unused __SLOW_DOWN_IO and SLOW_DOWN_IO definitions 2022-11-18 13:55:08 -08:00
block block-6.1-2022-11-05 2022-11-05 09:02:28 -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 proc: report open files as size in stat() for /proc/pid/fd 2022-11-18 13:55:07 -08:00
drivers cxl fixes for 6.1-rc4 2022-11-06 13:09:52 -08:00
fs nilfs2: fix shift-out-of-bounds/overflow in nilfs_sb2_bad_offset() 2022-11-18 13:55:08 -08:00
include proc: give /proc/cmdline size 2022-11-18 13:55:07 -08:00
init proc: give /proc/cmdline size 2022-11-18 13:55:07 -08:00
io_uring io_uring: unlock if __io_run_local_work locked inside 2022-10-27 09:52:12 -06:00
ipc ipc/msg.c: fix percpu_counter use after free 2022-10-28 13:37:22 -07:00
kernel kexec: replace crash_mem_range with range 2022-11-18 13:55:07 -08:00
lib llist: avoid extra memory read in llist_add_batch 2022-11-18 13:55:06 -08:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mmap: fix remap_file_pages() regression 2022-10-28 13:37:23 -07:00
net Networking fixes for 6.1-rc4, including fixes from bluetooth and 2022-11-03 10:51:59 -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 scripts: checkpatch: allow "case" macros 2022-11-18 13:55:08 -08:00
security lsm/stable-6.1 PR 20221031 2022-10-31 12:09:42 -07:00
sound ALSA: aoa: Fix I2S device accounting 2022-10-27 08:53:08 +02:00
tools proc: fixup uptime selftest 2022-11-18 13:55:08 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt Merge tag 'kvmarm-fixes-6.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD 2022-11-06 03:30:49 -05:00
.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
.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 MAINTAINERS: git://github -> https://github.com for linux-test-project 2022-11-18 13:55:06 -08:00
Makefile Linux 6.1-rc4 2022-11-06 15:07:11 -08:00
README

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.