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authorChao Yu <yuchao0@huawei.com>2020-09-29 04:22:50 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2020-09-29 12:12:41 +0300
commit6d7ab88a98c1b7a47c228f8ffb4f44d631eaf284 (patch)
treef2c2823d69cf9384289d8ab56ef58aa098e8dcba /fs/f2fs
parent17f930e0a649e158a567504df7bb01c90a8514c1 (diff)
downloadlinux-6d7ab88a98c1b7a47c228f8ffb4f44d631eaf284.tar.xz
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>
Diffstat (limited to 'fs/f2fs')
-rw-r--r--fs/f2fs/dir.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 74342d9836d7..264696495440 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -353,16 +353,15 @@ 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)) {
@@ -373,7 +372,6 @@ 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;