[PATCH v4] fsck.f2fs: check and fix i_namelen to avoid double free

From: Yunlong Song
Date: Mon Dec 18 2017 - 08:25:51 EST


v1 -> v2: use child_info to pass dentry namelen
v2 -> v3: check child != NULL to include the F2FS_FT_ORPHAN file type
v3 -> v4: fix the i_namelen problem of dump.f2fs

Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
---
fsck/fsck.c | 28 +++++++++++++++++++++++-----
fsck/fsck.h | 3 ++-
2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 2212aa3..5407cf2 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -539,7 +539,7 @@ int fsck_chk_node_blk(struct f2fs_sb_info *sbi, struct f2fs_inode *inode,

if (sanity_check_inode(sbi, node_blk))
goto err;
- fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni);
+ fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni, child);
quota_add_inode_usage(fsck->qctx, nid, &node_blk->i);
} else {
switch (ntype) {
@@ -633,7 +633,7 @@ unmatched:
/* start with valid nid and blkaddr */
void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
enum FILE_TYPE ftype, struct f2fs_node *node_blk,
- u32 *blk_cnt, struct node_info *ni)
+ u32 *blk_cnt, struct node_info *ni, struct child_info *child_d)
{
struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
struct child_info child;
@@ -850,8 +850,23 @@ skip_blkcnt_fix:
en = malloc(F2FS_NAME_LEN + 1);
ASSERT(en);

- namelen = convert_encrypted_name(node_blk->i.i_name,
- le32_to_cpu(node_blk->i.i_namelen),
+ namelen = le32_to_cpu(node_blk->i.i_namelen);
+ if (namelen > F2FS_NAME_LEN) {
+ if (child_d && child_d->i_namelen <= F2FS_NAME_LEN) {
+ ASSERT_MSG("ino: 0x%x has i_namelen: 0x%x, "
+ "but has %d characters for name",
+ nid, namelen, child_d->i_namelen);
+ if (c.fix_on) {
+ FIX_MSG("[0x%x] i_namelen=0x%x -> 0x%x", nid, namelen,
+ child_d->i_namelen);
+ node_blk->i.i_namelen = cpu_to_le32(child_d->i_namelen);
+ need_fix = 1;
+ }
+ namelen = child_d->i_namelen;
+ } else
+ namelen = F2FS_NAME_LEN;
+ }
+ namelen = convert_encrypted_name(node_blk->i.i_name, namelen,
en, file_enc_name(&node_blk->i));
en[namelen] = '\0';
if (ftype == F2FS_FT_ORPHAN)
@@ -1098,6 +1113,8 @@ int convert_encrypted_name(unsigned char *name, int len,
unsigned char *new, int enc_name)
{
if (!enc_name) {
+ if (len > F2FS_NAME_LEN)
+ len = F2FS_NAME_LEN;
memcpy(new, name, len);
new[len] = 0;
return len;
@@ -1414,9 +1431,10 @@ static int __chk_dentries(struct f2fs_sb_info *sbi, struct child_info *child,
dentry, max, i, last_blk, enc_name);

blk_cnt = 1;
+ child->i_namelen = name_len;
ret = fsck_chk_node_blk(sbi,
NULL, le32_to_cpu(dentry[i].ino),
- ftype, TYPE_INODE, &blk_cnt, NULL);
+ ftype, TYPE_INODE, &blk_cnt, child);

if (ret && c.fix_on) {
int j;
diff --git a/fsck/fsck.h b/fsck/fsck.h
index 0343fbd..d635c5a 100644
--- a/fsck/fsck.h
+++ b/fsck/fsck.h
@@ -54,6 +54,7 @@ struct child_info {
u32 pp_ino; /*parent parent ino*/
struct extent_info ei;
u32 last_blk;
+ u32 i_namelen; /* dentry namelen */
};

struct f2fs_fsck {
@@ -128,7 +129,7 @@ extern int fsck_chk_node_blk(struct f2fs_sb_info *, struct f2fs_inode *, u32,
enum FILE_TYPE, enum NODE_TYPE, u32 *,
struct child_info *);
extern void fsck_chk_inode_blk(struct f2fs_sb_info *, u32, enum FILE_TYPE,
- struct f2fs_node *, u32 *, struct node_info *);
+ struct f2fs_node *, u32 *, struct node_info *, struct child_info *);
extern int fsck_chk_dnode_blk(struct f2fs_sb_info *, struct f2fs_inode *,
u32, enum FILE_TYPE, struct f2fs_node *, u32 *,
struct child_info *, struct node_info *);
--
1.8.5.2