| Message ID | 20211011030956.2459172-1-mudongliangabcd@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: fix GPF in nilfs_mdt_destroy | expand |
On Mon, Oct 11, 2021 at 11:10 AM Dongliang Mu <mudongliangabcd@gmail.com> wrote: > > In alloc_inode, inode_init_always could return -NOMEM if > security_inode_alloc fails. In its error handling, i_callback and > nilfs_free_inode will be called. However, because inode->i_private is > not initialized due to the failure of security_inode_alloc, the function > nilfs_is_metadata_file_inode can return true and nilfs_mdt_destroy will > be executed to lead to GPF bug. > > Fix this bug by moving the assignment of inode->i_private before > security_inode_alloc. > ping? > BTW, this bug is triggered by fault injection in the syzkaller. > > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> > --- > fs/inode.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/inode.c b/fs/inode.c > index ed0cab8a32db..f6fce84bf550 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -160,6 +160,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode) > inode->i_dir_seq = 0; > inode->i_rdev = 0; > inode->dirtied_when = 0; > + inode->i_private = NULL; > > #ifdef CONFIG_CGROUP_WRITEBACK > inode->i_wb_frn_winner = 0; > @@ -194,7 +195,6 @@ int inode_init_always(struct super_block *sb, struct inode *inode) > lockdep_set_class_and_name(&mapping->invalidate_lock, > &sb->s_type->invalidate_lock_key, > "mapping.invalidate_lock"); > - inode->i_private = NULL; > inode->i_mapping = mapping; > INIT_HLIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */ > #ifdef CONFIG_FS_POSIX_ACL > -- > 2.25.1 >
diff --git a/fs/inode.c b/fs/inode.c index ed0cab8a32db..f6fce84bf550 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -160,6 +160,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode) inode->i_dir_seq = 0; inode->i_rdev = 0; inode->dirtied_when = 0; + inode->i_private = NULL; #ifdef CONFIG_CGROUP_WRITEBACK inode->i_wb_frn_winner = 0; @@ -194,7 +195,6 @@ int inode_init_always(struct super_block *sb, struct inode *inode) lockdep_set_class_and_name(&mapping->invalidate_lock, &sb->s_type->invalidate_lock_key, "mapping.invalidate_lock"); - inode->i_private = NULL; inode->i_mapping = mapping; INIT_HLIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */ #ifdef CONFIG_FS_POSIX_ACL
In alloc_inode, inode_init_always could return -NOMEM if security_inode_alloc fails. In its error handling, i_callback and nilfs_free_inode will be called. However, because inode->i_private is not initialized due to the failure of security_inode_alloc, the function nilfs_is_metadata_file_inode can return true and nilfs_mdt_destroy will be executed to lead to GPF bug. Fix this bug by moving the assignment of inode->i_private before security_inode_alloc. BTW, this bug is triggered by fault injection in the syzkaller. Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> --- fs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)