Paul P Komkoff Jr wrote:
>
> This is very funny.
Actually it's very bad. Thanks for reporting this.
> mke2fs -j -O dir_index -J size=192 -T news -N 1000100
> atest3 1000000
> (creat & write 1 byte to 1000000 files)
>
> free space on device became 0 and voila
>
> Unable to handle kernel paging request at virtual address 5a5a5b9e
Here's a fix:
If ext3_add_nondir() fails it will do an iput() of the inode. But we
continue to run ext3_mark_inode_dirty() against the potentially-freed
inode. This oopses when slab poisoning is enabled.
Fix it so that we only run ext3_mark_inode_dirty() if the inode was
successfully instantiated.
fs/ext3/namei.c | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)
--- 25/fs/ext3/namei.c~ext3-use-after-free Sat Dec 14 01:25:03 2002
+++ 25-akpm/fs/ext3/namei.c Sat Dec 14 01:25:53 2002
@@ -1566,8 +1566,11 @@ static int ext3_add_nondir(handle_t *han
{
int err = ext3_add_entry(handle, dentry, inode);
if (!err) {
- d_instantiate(dentry, inode);
- return 0;
+ err = ext3_mark_inode_dirty(handle, inode);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
}
ext3_dec_count(handle, inode);
iput(inode);
@@ -1609,7 +1612,6 @@ static int ext3_create (struct inode * d
else
inode->i_mapping->a_ops = &ext3_aops;
err = ext3_add_nondir(handle, dentry, inode);
- ext3_mark_inode_dirty(handle, inode);
}
ext3_journal_stop(handle, dir);
unlock_kernel();
@@ -1642,7 +1644,6 @@ static int ext3_mknod (struct inode * di
inode->i_op = &ext3_special_inode_operations;
#endif
err = ext3_add_nondir(handle, dentry, inode);
- ext3_mark_inode_dirty(handle, inode);
}
ext3_journal_stop(handle, dir);
unlock_kernel();
@@ -2105,7 +2106,6 @@ static int ext3_symlink (struct inode *
}
EXT3_I(inode)->i_disksize = inode->i_size;
err = ext3_add_nondir(handle, dentry, inode);
- ext3_mark_inode_dirty(handle, inode);
out_stop:
ext3_journal_stop(handle, dir);
unlock_kernel();
@@ -2140,7 +2140,6 @@ static int ext3_link (struct dentry * ol
atomic_inc(&inode->i_count);
err = ext3_add_nondir(handle, dentry, inode);
- ext3_mark_inode_dirty(handle, inode);
ext3_journal_stop(handle, dir);
unlock_kernel();
return err;
_
-
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This archive was generated by hypermail 2b29 : Sun Dec 15 2002 - 22:00:30 EST