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Yang Yang 90ada91f46 jffs2: check the validity of dstlen in jffs2_zlib_compress()
KASAN reports a BUG when download file in jffs2 filesystem.It is
because when dstlen == 1, cpage_out will write array out of bounds.
Actually, data will not be compressed in jffs2_zlib_compress() if
data's length less than 4.

[  393.799778] BUG: KASAN: slab-out-of-bounds in jffs2_rtime_compress+0x214/0x2f0 at addr ffff800062e3b281
[  393.809166] Write of size 1 by task tftp/2918
[  393.813526] CPU: 3 PID: 2918 Comm: tftp Tainted: G    B           4.9.115-rt93-EMBSYS-CGEL-6.1.R6-dirty #1
[  393.823173] Hardware name: LS1043A RDB Board (DT)
[  393.827870] Call trace:
[  393.830322] [<ffff20000808c700>] dump_backtrace+0x0/0x2f0
[  393.835721] [<ffff20000808ca04>] show_stack+0x14/0x20
[  393.840774] [<ffff2000086ef700>] dump_stack+0x90/0xb0
[  393.845829] [<ffff20000827b19c>] kasan_object_err+0x24/0x80
[  393.851402] [<ffff20000827b404>] kasan_report_error+0x1b4/0x4d8
[  393.857323] [<ffff20000827bae8>] kasan_report+0x38/0x40
[  393.862548] [<ffff200008279d44>] __asan_store1+0x4c/0x58
[  393.867859] [<ffff2000084ce2ec>] jffs2_rtime_compress+0x214/0x2f0
[  393.873955] [<ffff2000084bb3b0>] jffs2_selected_compress+0x178/0x2a0
[  393.880308] [<ffff2000084bb530>] jffs2_compress+0x58/0x478
[  393.885796] [<ffff2000084c5b34>] jffs2_write_inode_range+0x13c/0x450
[  393.892150] [<ffff2000084be0b8>] jffs2_write_end+0x2a8/0x4a0
[  393.897811] [<ffff2000081f3008>] generic_perform_write+0x1c0/0x280
[  393.903990] [<ffff2000081f5074>] __generic_file_write_iter+0x1c4/0x228
[  393.910517] [<ffff2000081f5210>] generic_file_write_iter+0x138/0x288
[  393.916870] [<ffff20000829ec1c>] __vfs_write+0x1b4/0x238
[  393.922181] [<ffff20000829ff00>] vfs_write+0xd0/0x238
[  393.927232] [<ffff2000082a1ba8>] SyS_write+0xa0/0x110
[  393.932283] [<ffff20000808429c>] __sys_trace_return+0x0/0x4
[  393.937851] Object at ffff800062e3b280, in cache kmalloc-64 size: 64
[  393.944197] Allocated:
[  393.946552] PID = 2918
[  393.948913]  save_stack_trace_tsk+0x0/0x220
[  393.953096]  save_stack_trace+0x18/0x20
[  393.956932]  kasan_kmalloc+0xd8/0x188
[  393.960594]  __kmalloc+0x144/0x238
[  393.963994]  jffs2_selected_compress+0x48/0x2a0
[  393.968524]  jffs2_compress+0x58/0x478
[  393.972273]  jffs2_write_inode_range+0x13c/0x450
[  393.976889]  jffs2_write_end+0x2a8/0x4a0
[  393.980810]  generic_perform_write+0x1c0/0x280
[  393.985251]  __generic_file_write_iter+0x1c4/0x228
[  393.990040]  generic_file_write_iter+0x138/0x288
[  393.994655]  __vfs_write+0x1b4/0x238
[  393.998228]  vfs_write+0xd0/0x238
[  394.001543]  SyS_write+0xa0/0x110
[  394.004856]  __sys_trace_return+0x0/0x4
[  394.008684] Freed:
[  394.010691] PID = 2918
[  394.013051]  save_stack_trace_tsk+0x0/0x220
[  394.017233]  save_stack_trace+0x18/0x20
[  394.021069]  kasan_slab_free+0x88/0x188
[  394.024902]  kfree+0x6c/0x1d8
[  394.027868]  jffs2_sum_write_sumnode+0x2c4/0x880
[  394.032486]  jffs2_do_reserve_space+0x198/0x598
[  394.037016]  jffs2_reserve_space+0x3f8/0x4d8
[  394.041286]  jffs2_write_inode_range+0xf0/0x450
[  394.045816]  jffs2_write_end+0x2a8/0x4a0
[  394.049737]  generic_perform_write+0x1c0/0x280
[  394.054179]  __generic_file_write_iter+0x1c4/0x228
[  394.058968]  generic_file_write_iter+0x138/0x288
[  394.063583]  __vfs_write+0x1b4/0x238
[  394.067157]  vfs_write+0xd0/0x238
[  394.070470]  SyS_write+0xa0/0x110
[  394.073783]  __sys_trace_return+0x0/0x4
[  394.077612] Memory state around the buggy address:
[  394.082404]  ffff800062e3b180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[  394.089623]  ffff800062e3b200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[  394.096842] >ffff800062e3b280: 01 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  394.104056]                    ^
[  394.107283]  ffff800062e3b300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[  394.114502]  ffff800062e3b380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[  394.121718] ==================================================================

Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:53:23 +01:00
Documentation - For syscall user dispatch, separate ptctl operation from syscall 2021-02-07 10:16:24 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch - For syscall user dispatch, separate ptctl operation from syscall 2021-02-07 10:16:24 -08:00
block block-5.11-2021-02-05 2021-02-06 14:40:27 -08:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto X.509: Fix crash caused by NULL pointer 2021-01-20 11:33:51 -08:00
drivers ubi: eba: Delete useless kfree code 2021-02-12 21:53:22 +01:00
fs jffs2: check the validity of dstlen in jffs2_zlib_compress() 2021-02-12 21:53:23 +01:00
include - Prevent device managed IRQ allocation helpers from returning IRQ 0. 2021-02-07 10:25:01 -08:00
init init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov 2021-02-05 11:03:47 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
kernel dma-mapping fixes for 5.11: 2021-02-07 10:40:48 -08:00
lib - Revert an attempt to not spread IRQ threads on isolated CPUs which has 2021-02-07 10:03:43 -08:00
mm mm: hugetlb: fix missing put_page in gather_surplus_pages() 2021-02-05 11:03:47 -08:00
net Fixes: 2021-02-05 10:11:14 -08:00
samples ARM: SoC drivers for v5.11 2020-12-16 16:38:41 -08:00
scripts kallsyms: fix nonconverging kallsyms table with lld 2021-02-05 17:53:28 +09:00
security cap: fix conversions on getxattr 2021-01-28 10:22:48 +01:00
sound ALSA: hda/via: Apply the workaround generically for Clevo machines 2021-01-26 18:05:03 +01:00
tools libnvdimm for 5.11-rc7 2021-02-07 10:45:26 -08:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM/arm64 fixes for 5.11, take #2 2021-01-25 18:52:01 -05:00
.clang-format clang-format: Update with the latest for_each macro list 2021-01-29 15:00:23 +01:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap block-5.11-2021-02-05 2021-02-06 14:40:27 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: dccp: move Gerrit Renker to CREDITS 2021-01-14 10:53:49 -08:00
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 MAINTAINERS/.mailmap: use my @kernel.org address 2021-02-05 11:03:47 -08:00
Makefile Linux 5.11-rc7 2021-02-07 13:57:38 -08:00
README

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.