| Message ID | CAJFZqHzey9rNoX-EnNQ344_QNVwObdGKtX-GT61qwh3-8SeStA@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 22a3676..baed6c0 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -879,6 +879,7 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, u64 subvol_objectid = 0; u64 subvol_rootid = 0; int error = 0; + u16 csum_size; if (!(flags & MS_RDONLY))
Do you means we can handle it like below? I think it is not better, if that, csum size can not the expand, and the code in csum_tree_block seems redundancy; If you do not want to truncate in first patch, I think we can try to avoid it mode |= FMODE_WRITE; @@ -974,6 +975,13 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, return root; } + csum_size = btrfs_super_csum_size(root->fs_info->super_copy); + if (csum_size > 4) { + printk(KERN_ERR "btrfs: csume size is larger than 4\n"); + deactivate_locked_super(s); + return -EINVAL; + } + return root; error_close_devices: On Thu, Sep 11, 2014 at 10:02 PM, Chris Mason <clm@fb.com> wrote: > On 09/09/2014 05:19 AM, rongqing.li@windriver.com wrote: >> From: Li RongQing <roy.qing.li@gmail.com> >> >> It is impossible that csum_size is larger than sizeof(long), but the codes >> still add the handler for this condition, like allocate new memory, for >> extension. If it becomes true someday, copying csum_size size memory to local >> 32bit variable found and val will overflow these two variables. >> >> Fix it by returning the max 4 byte checksum. > > Thanks for the patch. I'd rather not silently truncate the copy down > though. How about a one time check at mount to make sure the value in > the super is reasonable? > > -chris > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html