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Desmond Cheong Zhi Xi af1178296d hfs: fix high memory mapping in hfs_bnode_read
[ Upstream commit 54a5ead6f5e2b47131a7385d0c0af18e7b89cb02 ]

Pages that we read in hfs_bnode_read need to be kmapped into kernel
address space.  However, currently only the 0th page is kmapped.  If the
given offset + length exceeds this 0th page, then we have an invalid
memory access.

To fix this, we kmap relevant pages one by one and copy their relevant
portions of data.

An example of invalid memory access occurring without this fix can be seen
in the following crash report:

  ==================================================================
  BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline]
  BUG: KASAN: use-after-free in hfs_bnode_read+0xc4/0xe0 fs/hfs/bnode.c:26
  Read of size 2 at addr ffff888125fdcffe by task syz-executor5/4634

  CPU: 0 PID: 4634 Comm: syz-executor5 Not tainted 5.13.0-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:79 [inline]
   dump_stack+0x195/0x1f8 lib/dump_stack.c:120
   print_address_description.constprop.0+0x1d/0x110 mm/kasan/report.c:233
   __kasan_report mm/kasan/report.c:419 [inline]
   kasan_report.cold+0x7b/0xd4 mm/kasan/report.c:436
   check_region_inline mm/kasan/generic.c:180 [inline]
   kasan_check_range+0x154/0x1b0 mm/kasan/generic.c:186
   memcpy+0x24/0x60 mm/kasan/shadow.c:65
   memcpy include/linux/fortify-string.h:191 [inline]
   hfs_bnode_read+0xc4/0xe0 fs/hfs/bnode.c:26
   hfs_bnode_read_u16 fs/hfs/bnode.c:34 [inline]
   hfs_bnode_find+0x880/0xcc0 fs/hfs/bnode.c:365
   hfs_brec_find+0x2d8/0x540 fs/hfs/bfind.c:126
   hfs_brec_read+0x27/0x120 fs/hfs/bfind.c:165
   hfs_cat_find_brec+0x19a/0x3b0 fs/hfs/catalog.c:194
   hfs_fill_super+0xc13/0x1460 fs/hfs/super.c:419
   mount_bdev+0x331/0x3f0 fs/super.c:1368
   hfs_mount+0x35/0x40 fs/hfs/super.c:457
   legacy_get_tree+0x10c/0x220 fs/fs_context.c:592
   vfs_get_tree+0x93/0x300 fs/super.c:1498
   do_new_mount fs/namespace.c:2905 [inline]
   path_mount+0x13f5/0x20e0 fs/namespace.c:3235
   do_mount fs/namespace.c:3248 [inline]
   __do_sys_mount fs/namespace.c:3456 [inline]
   __se_sys_mount fs/namespace.c:3433 [inline]
   __x64_sys_mount+0x2b8/0x340 fs/namespace.c:3433
   do_syscall_64+0x37/0xc0 arch/x86/entry/common.c:47
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x45e63a
  Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 88 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f9404d410d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 0000000020000248 RCX: 000000000045e63a
  RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f9404d41120
  RBP: 00007f9404d41120 R08: 00000000200002c0 R09: 0000000020000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
  R13: 0000000000000003 R14: 00000000004ad5d8 R15: 0000000000000000

  The buggy address belongs to the page:
  page:00000000dadbcf3e refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x125fdc
  flags: 0x2fffc0000000000(node=0|zone=2|lastcpupid=0x3fff)
  raw: 02fffc0000000000 ffffea000497f748 ffffea000497f6c8 0000000000000000
  raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff888125fdce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
   ffff888125fdcf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  >ffff888125fdcf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                  ^
   ffff888125fdd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
   ffff888125fdd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ==================================================================

Link: https://lkml.kernel.org/r/20210701030756.58760-3-desmondcheongzx@gmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31 08:19:38 +02:00
arch KVM: x86: determine if an exception has an error code only when injecting it. 2021-07-31 08:19:37 +02:00
block rq-qos: fix missed wake-ups in rq_qos_throttle try two 2021-07-19 08:53:16 +02:00
certs certs: Move load_system_certificate_list to a common function 2021-06-30 08:47:55 -04:00
crypto crypto: shash - avoid comparing pointers to exported functions under CFI 2021-07-14 16:53:13 +02:00
Documentation userfaultfd: do not untag user pointers 2021-07-28 13:31:01 +02:00
drivers xhci: add xhci_get_virt_ep() helper 2021-07-28 13:31:02 +02:00
fs hfs: fix high memory mapping in hfs_bnode_read 2021-07-31 08:19:38 +02:00
include sctp: move 198 addresses from unusable to private scope 2021-07-31 08:19:38 +02:00
init kbuild: add CONFIG_LD_IS_LLD 2021-06-30 08:47:44 -04:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel cgroup1: fix leaked context root causing sporadic NULL deref in LTP 2021-07-31 08:19:37 +02:00
lib lib/decompress_unlz4.c: correctly handle zero-padding around initrds. 2021-07-20 16:10:46 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm: slab: fix kmem_cache_create failed when sysfs node not destroyed 2021-07-25 14:35:14 +02:00
net ipv6: allocate enough headroom in ip6_finish_output2() 2021-07-31 08:19:38 +02:00
samples samples/bpf: Fix the error return code of xdp_redirect's main() 2021-07-14 16:53:30 +02:00
scripts kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set 2021-07-25 14:35:12 +02:00
security smackfs: restrict bytes count in smk_set_cipso() 2021-07-19 08:53:18 +02:00
sound ALSA: hdmi: Expose all pins on MSI MS-7C94 board 2021-07-28 13:30:59 +02:00
tools tools: Allow proper CC/CXX/... override with LLVM=1 in Makefile.include 2021-07-31 08:19:37 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio 2021-07-20 16:10:40 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.136 2021-07-28 13:31:02 +02:00
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.