Re: [PATCH 1/2] ubifs: xattr: Fix some potential memory leaks while iterating entries
On Mon, Sep 14, 2020 at 5:25 AM Zhihao Cheng wrote: > 在 2020/9/14 3:08, Richard Weinberger 写道: > > On Mon, Jun 1, 2020 at 11:11 AM Zhihao Cheng > > wrote: > The kill_xattrs process is more intuitive without the pxent. However, > the release process for the memory (stores xent->name) is similar to > 'pxent'. If you think it's better than v1, I will send v2. You are right. We don't gain much. So I'll take v1. Thanks a lot for fixing! -- Thanks, //richard
Re: [PATCH 1/2] ubifs: xattr: Fix some potential memory leaks while iterating entries
在 2020/9/14 3:08, Richard Weinberger 写道:
On Mon, Jun 1, 2020 at 11:11 AM Zhihao Cheng wrote:
I agree that this needs fixing. Did you also look into getting rid of pxent?
UBIFS uses the pxent pattern over and over and the same error got copy pasted
a lot. :-(
I thought about it. I'm not sure whether it is good to drop 'pxent'.
Maybe you mean doing changes looks like following(Takes
ubifs_jnl_write_inode() for example):
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index 4a5b06f8d812..fcd5ac047b34 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -879,13 +879,19 @@ int ubifs_jnl_write_inode(struct ubifs_info *c,
const struct inode *inode)
union ubifs_key key;
struct fscrypt_name nm = {0};
struct inode *xino;
- struct ubifs_dent_node *xent, *pxent = NULL;
+ struct ubifs_dent_node *xent;
if (ui->xattr_cnt >= ubifs_xattr_max_cnt(c)) {
ubifs_err(c, "Cannot delete inode, it has too much
xattrs!");
goto out_release;
}
+ fname_name(&nm) = kmalloc(UBIFS_MAX_NLEN, GFP_NOFS);
+ if (!fname_name(&nm)) {
+ err = -ENOMEM;
+ goto out_release;
+ }
+
lowest_xent_key(c, &key, inode->i_ino);
while (1) {
xent = ubifs_tnc_next_ent(c, &key, &nm);
@@ -894,11 +900,12 @@ int ubifs_jnl_write_inode(struct ubifs_info *c,
const struct inode *inode)
if (err == -ENOENT)
break;
+ kfree(fname_name(&nm));
goto out_release;
}
- fname_name(&nm) = xent->name;
fname_len(&nm) = le16_to_cpu(xent->nlen);
+ strncpy(fname_name(&nm), xent->name, fname_len(&nm));
xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum));
if (IS_ERR(xino)) {
@@ -907,6 +914,7 @@ int ubifs_jnl_write_inode(struct ubifs_info *c,
const struct inode *inode)
xent->name, err);
ubifs_ro_mode(c, err);
kfree(xent);
+ kfree(fname_name(&nm));
goto out_release;
}
ubifs_assert(c, ubifs_inode(xino)->xattr);
@@ -916,11 +924,10 @@ int ubifs_jnl_write_inode(struct ubifs_info *c,
const struct inode *inode)
ino = (void *)ino + UBIFS_INO_NODE_SZ;
iput(xino);
- kfree(pxent);
- pxent = xent;
key_read(c, &xent->key, &key);
+ kfree(xent);
}
- kfree(pxent);
+ kfree(fname_name(&nm));
}
pack_inode(c, ino, inode, 1);
The kill_xattrs process is more intuitive without the pxent. However,
the release process for the memory (stores xent->name) is similar to
'pxent'. If you think it's better than v1, I will send v2.
Re: [PATCH 1/2] ubifs: xattr: Fix some potential memory leaks while iterating entries
On Mon, Jun 1, 2020 at 11:11 AM Zhihao Cheng wrote:
>
> Fix some potential memory leaks in error handling branches while
> iterating xattr entries. For example, function ubifs_tnc_remove_ino()
> forgets to free pxent if it exists. Similar problems also exist in
> ubifs_purge_xattrs(), ubifs_add_orphan() and ubifs_jnl_write_inode().
>
> Signed-off-by: Zhihao Cheng
> Cc:
> Fixes: 1e51764a3c2ac05a2 ("UBIFS: add new flash file system")
I agree that this needs fixing. Did you also look into getting rid of pxent?
UBIFS uses the pxent pattern over and over and the same error got copy pasted
a lot. :-(
--
Thanks,
//richard
[PATCH 1/2] ubifs: xattr: Fix some potential memory leaks while iterating entries
Fix some potential memory leaks in error handling branches while
iterating xattr entries. For example, function ubifs_tnc_remove_ino()
forgets to free pxent if it exists. Similar problems also exist in
ubifs_purge_xattrs(), ubifs_add_orphan() and ubifs_jnl_write_inode().
Signed-off-by: Zhihao Cheng
Cc:
Fixes: 1e51764a3c2ac05a2 ("UBIFS: add new flash file system")
---
fs/ubifs/journal.c | 2 ++
fs/ubifs/orphan.c | 2 ++
fs/ubifs/tnc.c | 3 +++
fs/ubifs/xattr.c | 2 ++
4 files changed, 9 insertions(+)
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index e5ec1afe1c66..0b4b94b079a6 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -893,6 +893,7 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const
struct inode *inode)
if (err == -ENOENT)
break;
+ kfree(pxent);
goto out_release;
}
@@ -905,6 +906,7 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const
struct inode *inode)
ubifs_err(c, "dead directory entry '%s', error
%d",
xent->name, err);
ubifs_ro_mode(c, err);
+ kfree(pxent);
kfree(xent);
goto out_release;
}
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c
index 283f9eb48410..b0117878b3a0 100644
--- a/fs/ubifs/orphan.c
+++ b/fs/ubifs/orphan.c
@@ -173,6 +173,7 @@ int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
err = PTR_ERR(xent);
if (err == -ENOENT)
break;
+ kfree(pxent);
return err;
}
@@ -182,6 +183,7 @@ int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
xattr_orphan = orphan_add(c, xattr_inum, orphan);
if (IS_ERR(xattr_orphan)) {
+ kfree(pxent);
kfree(xent);
return PTR_ERR(xattr_orphan);
}
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index e8e7b0e9532e..33742ee3945b 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -2885,6 +2885,7 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
err = PTR_ERR(xent);
if (err == -ENOENT)
break;
+ kfree(pxent);
return err;
}
@@ -2898,6 +2899,7 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
fname_len(&nm) = le16_to_cpu(xent->nlen);
err = ubifs_tnc_remove_nm(c, &key1, &nm);
if (err) {
+ kfree(pxent);
kfree(xent);
return err;
}
@@ -2906,6 +2908,7 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
highest_ino_key(c, &key2, xattr_inum);
err = ubifs_tnc_remove_range(c, &key1, &key2);
if (err) {
+ kfree(pxent);
kfree(xent);
return err;
}
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 9aefbb60074f..a0b9b349efe6 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -522,6 +522,7 @@ int ubifs_purge_xattrs(struct inode *host)
xent->name, err);
ubifs_ro_mode(c, err);
kfree(pxent);
+ kfree(xent);
return err;
}
@@ -531,6 +532,7 @@ int ubifs_purge_xattrs(struct inode *host)
err = remove_xattr(c, host, xino, &nm);
if (err) {
kfree(pxent);
+ kfree(xent);
iput(xino);
ubifs_err(c, "cannot remove xattr, error %d", err);
return err;
--
2.25.4
