diff mbox series

[v2] erofs: fix general protection fault when reading fragment

Message ID 20221021085325.25788-1-zbestahu@gmail.com
State New
Headers
Series [v2] erofs: fix general protection fault when reading fragment |

Commit Message

Yue Hu Oct. 21, 2022, 8:53 a.m. UTC 
  From: Yue Hu <huyue2@coolpad.com>

As syzbot reported [1], the fragment feature sb flag is not set, so
packed_inode != NULL needs to be checked in z_erofs_read_fragment().

[1] https://lore.kernel.org/all/0000000000002e7a8905eb841ddd@google.com/

Reported-by: syzbot+3faecbfd845a895c04cb@syzkaller.appspotmail.com
Fixes: 08a0c9ef3e7e ("erofs: support on-disk compressed fragments data")
Signed-off-by: Yue Hu <huyue2@coolpad.com>
---
v2: fix return value to -EFSCURRUPTED (Xiang)

 fs/erofs/zdata.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Gao Xiang Nov. 7, 2022, 3:04 a.m. UTC | #1 
On Fri, Oct 21, 2022 at 04:53:25PM +0800, Yue Hu wrote:
> From: Yue Hu <huyue2@coolpad.com>
> 
> As syzbot reported [1], the fragment feature sb flag is not set, so
> packed_inode != NULL needs to be checked in z_erofs_read_fragment().
> 
> [1] https://lore.kernel.org/all/0000000000002e7a8905eb841ddd@google.com/
> 
> Reported-by: syzbot+3faecbfd845a895c04cb@syzkaller.appspotmail.com
> Fixes: 08a0c9ef3e7e ("erofs: support on-disk compressed fragments data")
> Signed-off-by: Yue Hu <huyue2@coolpad.com>

Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Thanks,
Gao Xiang

> ---
> v2: fix return value to -EFSCURRUPTED (Xiang)
> 
>  fs/erofs/zdata.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index cce56dde135c..55c13cd6934b 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -659,6 +659,9 @@ static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos,
>  	u8 *src, *dst;
>  	unsigned int i, cnt;
>  
> +	if (!packed_inode)
> +		return -EFSCORRUPTED;
> +
>  	pos += EROFS_I(inode)->z_fragmentoff;
>  	for (i = 0; i < len; i += cnt) {
>  		cnt = min_t(unsigned int, len - i,
> -- 
> 2.17.1
Chao Yu Nov. 8, 2022, 3:06 a.m. UTC | #2 
On 2022/10/21 16:53, Yue Hu wrote:
> From: Yue Hu <huyue2@coolpad.com>
> 
> As syzbot reported [1], the fragment feature sb flag is not set, so
> packed_inode != NULL needs to be checked in z_erofs_read_fragment().
> 
> [1] https://lore.kernel.org/all/0000000000002e7a8905eb841ddd@google.com/
> 
> Reported-by: syzbot+3faecbfd845a895c04cb@syzkaller.appspotmail.com
> Fixes: 08a0c9ef3e7e ("erofs: support on-disk compressed fragments data")
> Signed-off-by: Yue Hu <huyue2@coolpad.com>

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

Thanks,
diff mbox series

Patch

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index cce56dde135c..55c13cd6934b 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -659,6 +659,9 @@  static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos,
 	u8 *src, *dst;
 	unsigned int i, cnt;
 
+	if (!packed_inode)
+		return -EFSCORRUPTED;
+
 	pos += EROFS_I(inode)->z_fragmentoff;
 	for (i = 0; i < len; i += cnt) {
 		cnt = min_t(unsigned int, len - i,