[PATCH 1/5] f2fs: remove f2fs_bug_on in terms of max_depth

From: Jaegeuk Kim
Date: Thu Dec 31 2015 - 18:51:07 EST


There is no report on this bug_on case, but if malicious attacker changed this
field intentionally, we can just reset it as a MAX value.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/dir.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 3da5826..29bb8dd 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -172,8 +172,6 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,

namehash = f2fs_dentry_hash(&name);

- f2fs_bug_on(F2FS_I_SB(dir), level > MAX_DIR_HASH_DEPTH);
-
nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
nblock = bucket_blocks(level);

@@ -238,6 +236,14 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
goto out;

max_depth = F2FS_I(dir)->i_current_depth;
+ if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
+ f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
+ "Corrupted max_depth of %lu: %u",
+ dir->i_ino, max_depth);
+ max_depth = MAX_DIR_HASH_DEPTH;
+ F2FS_I(dir)->i_current_depth = max_depth;
+ mark_inode_dirty(dir);
+ }

for (level = 0; level < max_depth; level++) {
de = find_in_level(dir, level, &fname, res_page);
--
2.6.3

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