Re: [PATCH 6.1.y] hfs: fix general protection fault in hfs_find_init()

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Mar 29, 2026 at 05:49:18AM +0000, driz2t@qq.com wrote:
> PATCH] This is a backport for 6.1.y.

Odd text, but also:

> 
> [ Upstream commit 736a0516a16268995f4898eded49bfef077af709 ]
> 
> The hfs_find_init() method can trigger a crash if tree pointer is NULL.
> 
> hfs_fill_super() calls hfs_mdb_get(), which tries to construct Extents
> Tree and Catalog Tree. However, hfs_btree_open() calls read_mapping_page(),
> which calls hfs_get_block(), and that in turn calls hfs_ext_read_extent().
> 
> The problem is that hfs_find_init() tries to use
> HFS_SB(inode->i_sb)->ext_tree before it has been initialized. It will
> only be initialized after hfs_btree_open() finishes.
> 
> Fix this by checking the tree pointer in hfs_find_init() and reworking
> hfs_btree_open() to read the b-tree header directly from the volume.
> Replace read_mapping_page() with filemap_grab_folio(), then use sb_bread()
> to extract the b-tree header content and copy it into the folio.
> 
> Reported-by: Wenzhi Wang <wenzhi.wang@uwaterloo.ca>
> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
> Cc: Yangtao Li <frank.li@vivo.com>
> Cc: linux-fsdevel@vger.kernel.org
> Link: https://lore.kernel.org/r/20250710213657.108285-1-slava@dubeyko.com
> Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
> Signed-off-by: Changjian Liu <driz2t@qq.com>
> ---
>  fs/hfs/bfind.c  |  3 +++
>  fs/hfs/btree.c  | 33 +++++++++++++++++++++++----------
>  fs/hfs/extent.c |  2 +-
>  fs/hfs/hfs_fs.h |  1 +
>  4 files changed, 28 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
> index 6d37b4c75903..1b1cbb589f82 100644
> --- a/fs/hfs/bfind.c
> +++ b/fs/hfs/bfind.c
> @@ -16,6 +16,9 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
>  {
>       void *ptr;
>  
> +if (!tree || !fd)
> +     return -EINVAL;
> +
>       fd->tree = tree;
>       fd->bnode = NULL;
>       ptr = kzalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);

Your patch is completly corrupted and can not be applied :(

please fix your email client to work properly when sending patches.

thanks,

greg k-h