Re: [PATCH] f2fs: fix null-ptr-deref in f2fs_submit_page_bio()

[Chao Yu <chao@kernel.org>]

On 2024/10/12 0:44, Ye Bin wrote:
> From: Ye Bin <yebin10@huawei.com>
> 
> There's issue as follows when concurrently installing the f2fs.ko
> module and mounting the f2fs file system:
> KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
> RIP: 0010:__bio_alloc+0x2fb/0x6c0 [f2fs]
> Call Trace:
>   <TASK>
>   f2fs_submit_page_bio+0x126/0x8b0 [f2fs]
>   __get_meta_page+0x1d4/0x920 [f2fs]
>   get_checkpoint_version.constprop.0+0x2b/0x3c0 [f2fs]
>   validate_checkpoint+0xac/0x290 [f2fs]
>   f2fs_get_valid_checkpoint+0x207/0x950 [f2fs]
>   f2fs_fill_super+0x1007/0x39b0 [f2fs]
>   mount_bdev+0x183/0x250
>   legacy_get_tree+0xf4/0x1e0
>   vfs_get_tree+0x88/0x340
>   do_new_mount+0x283/0x5e0
>   path_mount+0x2b2/0x15b0
>   __x64_sys_mount+0x1fe/0x270
>   do_syscall_64+0x5f/0x170
>   entry_SYSCALL_64_after_hwframe+0x76/0x7e
> 
> Above issue happens as the biset of the f2fs file system is not
> initialized before register "f2fs_fs_type".
> To address above issue just register "f2fs_fs_type" at the last in
> init_f2fs_fs(). Ensure that all f2fs file system resources are
> initialized.
> 
> Fixes: f543805fcd60 ("f2fs: introduce private bioset")
> Signed-off-by: Ye Bin <yebin10@huawei.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,