Chao Yu 6d7ab88a98 f2fs: fix uninit-value in f2fs_lookup
As syzbot reported:

Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219
 f2fs_lookup+0xe05/0x1a80 fs/f2fs/namei.c:503
 lookup_open fs/namei.c:3082 [inline]
 open_last_lookups fs/namei.c:3177 [inline]
 path_openat+0x2729/0x6a90 fs/namei.c:3365
 do_filp_open+0x2b8/0x710 fs/namei.c:3395
 do_sys_openat2+0xa88/0x1140 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_compat_sys_openat fs/open.c:1242 [inline]
 __se_compat_sys_openat+0x2a4/0x310 fs/open.c:1240
 __ia32_compat_sys_openat+0x56/0x70 fs/open.c:1240
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

In f2fs_lookup(), @res_page could be used before being initialized,
because in __f2fs_find_entry(), once F2FS_I(dir)->i_current_depth was
been fuzzed to zero, then @res_page will never be initialized, causing
this kmsan warning, relocating @res_page initialization place to fix
this bug.

Reported-by: syzbot+0eac6f0bbd558fd866d7@syzkaller.appspotmail.com
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2020-09-29 02:12:41 -07:00
2020-09-29 02:12:41 -07:00
2020-09-11 11:11:25 -07:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%