| Message ID | 20240913110013.151331-2-thorsten.blum@toblux.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ext4: Annotate struct fname with __counted_by() | expand |
On Fri 13-09-24 13:00:14, Thorsten Blum wrote: > Add the __counted_by compiler attribute to the flexible array member > name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and > CONFIG_FORTIFY_SOURCE. > > Inline and use struct_size() to calculate the number of bytes to > allocate for new_fn and remove the local variable len. > > Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/dir.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c > index ff4514e4626b..8e7df15bb971 100644 > --- a/fs/ext4/dir.c > +++ b/fs/ext4/dir.c > @@ -408,7 +408,7 @@ struct fname { > __u32 inode; > __u8 name_len; > __u8 file_type; > - char name[]; > + char name[] __counted_by(name_len); > }; > > /* > @@ -464,14 +464,13 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, > struct rb_node **p, *parent = NULL; > struct fname *fname, *new_fn; > struct dir_private_info *info; > - int len; > > info = dir_file->private_data; > p = &info->root.rb_node; > > /* Create and allocate the fname structure */ > - len = sizeof(struct fname) + ent_name->len + 1; > - new_fn = kzalloc(len, GFP_KERNEL); > + new_fn = kzalloc(struct_size(new_fn, name, ent_name->len + 1), > + GFP_KERNEL); > if (!new_fn) > return -ENOMEM; > new_fn->hash = hash; > -- > 2.46.0 > >
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index ff4514e4626b..8e7df15bb971 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -408,7 +408,7 @@ struct fname { __u32 inode; __u8 name_len; __u8 file_type; - char name[]; + char name[] __counted_by(name_len); }; /* @@ -464,14 +464,13 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, struct rb_node **p, *parent = NULL; struct fname *fname, *new_fn; struct dir_private_info *info; - int len; info = dir_file->private_data; p = &info->root.rb_node; /* Create and allocate the fname structure */ - len = sizeof(struct fname) + ent_name->len + 1; - new_fn = kzalloc(len, GFP_KERNEL); + new_fn = kzalloc(struct_size(new_fn, name, ent_name->len + 1), + GFP_KERNEL); if (!new_fn) return -ENOMEM; new_fn->hash = hash;
Add the __counted_by compiler attribute to the flexible array member name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Inline and use struct_size() to calculate the number of bytes to allocate for new_fn and remove the local variable len. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> --- fs/ext4/dir.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)