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Baokun Li 88618feecf ubifs: fix slab-out-of-bounds in ubifs_change_lp
Hulk Robot reported a KASAN report about slab-out-of-bounds:
 ==================================================================
 BUG: KASAN: slab-out-of-bounds in ubifs_change_lp+0x3a9/0x1390 [ubifs]
 Read of size 8 at addr ffff888101c961f8 by task fsstress/1068
 [...]
 Call Trace:
  check_memory_region+0x1c1/0x1e0
  ubifs_change_lp+0x3a9/0x1390 [ubifs]
  ubifs_change_one_lp+0x170/0x220 [ubifs]
  ubifs_garbage_collect+0x7f9/0xda0 [ubifs]
  ubifs_budget_space+0xfe4/0x1bd0 [ubifs]
  ubifs_write_begin+0x528/0x10c0 [ubifs]

 Allocated by task 1068:
  kmemdup+0x25/0x50
  ubifs_lpt_lookup_dirty+0x372/0xb00 [ubifs]
  ubifs_update_one_lp+0x46/0x260 [ubifs]
  ubifs_tnc_end_commit+0x98b/0x1720 [ubifs]
  do_commit+0x6cb/0x1950 [ubifs]
  ubifs_run_commit+0x15a/0x2b0 [ubifs]
  ubifs_budget_space+0x1061/0x1bd0 [ubifs]
  ubifs_write_begin+0x528/0x10c0 [ubifs]
 [...]
 ==================================================================

In ubifs_garbage_collect(), if ubifs_find_dirty_leb returns an error,
lp is an uninitialized variable. But lp.num might be used in the out
branch, which is a random value. If the value is -1 or another value
that can pass the check, soob may occur in the ubifs_change_lp() in
the following procedure.

To solve this problem, we initialize lp.lnum to -1, and then initialize
it correctly in ubifs_find_dirty_leb, which is not equal to -1, and
ubifs_return_leb is executed only when lp.lnum != -1.

if find a retained or indexing LEB and continue to next loop, but break
before find another LEB, the "taken" flag of this LEB will be cleaned
in ubi_return_lebi(). This bug has also been fixed in this patch.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-23 22:23:58 +01:00
arch Two small fixes, one of which was being worked around in selftests. 2021-12-19 12:44:03 -08:00
block block-5.16-2021-12-19 2021-12-19 12:38:53 -08:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto Update to zstd-1.4.10 2021-11-13 15:32:30 -08:00
Documentation ubifs: Document sysfs nodes 2021-12-23 20:23:42 +01:00
drivers ubi: Fix a mistake in comment 2021-12-23 20:23:40 +01:00
fs ubifs: fix slab-out-of-bounds in ubifs_change_lp 2021-12-23 22:23:58 +01:00
include Networking fixes for 5.16-rc6, including fixes from mac80211, wifi, bpf. 2021-12-16 15:02:14 -08:00
init kbuild: Fix -Wimplicit-fallthrough=5 error for GCC 5.x and 6.x 2021-11-14 18:59:49 -08:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-11-20 10:35:54 -08:00
kernel - Make sure the CLOCK_REALTIME to CLOCK_MONOTONIC offset is never positive 2021-12-19 12:23:18 -08:00
lib Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2021-12-08 16:06:44 -08:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm Merge branch 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu 2021-12-11 16:14:17 -08:00
net Networking fixes for 5.16-rc6, including fixes from mac80211, wifi, bpf. 2021-12-16 15:02:14 -08:00
samples ftrace/samples: Add module to test multi direct modify interface 2021-12-09 13:02:44 -05:00
scripts recordmcount.pl: look for jgnop instruction as well as bcrl on s390 2021-12-12 18:52:26 +01:00
security selinux: fix sleeping function called from invalid context 2021-12-16 17:47:39 -05:00
sound sound fixes for 5.16-rc5 2021-12-10 11:43:00 -08:00
tools Two small fixes, one of which was being worked around in selftests. 2021-12-19 12:44:03 -08:00
usr initramfs: Check timestamp to prevent broken cpio archive 2021-10-24 13:48:40 +09:00
virt KVM: downgrade two BUG_ONs to WARN_ON_ONCE 2021-11-26 06:43:28 -05:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update email address for Guo Ren 2021-12-10 17:10:55 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ubifs: Document sysfs nodes 2021-12-23 20:23:42 +01:00
Makefile Linux 5.16-rc6 2021-12-19 14:14:33 -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.