| From c7dbda0ad137f297d9928b3290bddd9d45ad0d01 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 29 Sep 2020 09:22:50 +0800 |
| Subject: f2fs: fix uninit-value in f2fs_lookup |
| |
| From: Chao Yu <yuchao0@huawei.com> |
| |
| [ Upstream commit 6d7ab88a98c1b7a47c228f8ffb4f44d631eaf284 ] |
| |
| 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> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| fs/f2fs/dir.c | 8 +++----- |
| 1 file changed, 3 insertions(+), 5 deletions(-) |
| |
| diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c |
| index 069f498af1e38..ceb4431b56690 100644 |
| --- a/fs/f2fs/dir.c |
| +++ b/fs/f2fs/dir.c |
| @@ -357,16 +357,15 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, |
| unsigned int max_depth; |
| unsigned int level; |
| |
| + *res_page = NULL; |
| + |
| if (f2fs_has_inline_dentry(dir)) { |
| - *res_page = NULL; |
| de = f2fs_find_in_inline_dir(dir, fname, res_page); |
| goto out; |
| } |
| |
| - if (npages == 0) { |
| - *res_page = NULL; |
| + if (npages == 0) |
| goto out; |
| - } |
| |
| max_depth = F2FS_I(dir)->i_current_depth; |
| if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) { |
| @@ -377,7 +376,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, |
| } |
| |
| for (level = 0; level < max_depth; level++) { |
| - *res_page = NULL; |
| de = find_in_level(dir, level, fname, res_page); |
| if (de || IS_ERR(*res_page)) |
| break; |
| -- |
| 2.27.0 |
| |