| Message ID | 5347967B.5090401@huawei.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Fri, Apr 11, 2014 at 03:15:07PM +0800, Zhang Zhen wrote: > In ext4_xattr_set_handle() we have checked the xattr name's length. So we should > also check it in ext4_xattr_get() to avoid unneeded lookup caused by invalid name. > > Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Applied, although I dropped this bit: > In addition, we deleted the check of NULL in ext4_xattr_set_handle(), because in all > the callers of the ext4_xattr_set_handle(), the name can't be NULL. Verifying this is non-trivial, since there are many non-local users of this function, and in order to make sure this is true you need to verify (at least) the callers of the callers. I could be convinced to turn this into a BUG_ON(!name), or "if (unlikely(!name))", but leaving the check in is a good idea, since even if it is true today, it's not necessarily guarantted to be true N years in the future. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 1f5cf58..340bdfa 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -369,6 +369,9 @@ ext4_xattr_get(struct inode *inode, int name_index, const char *name, { int error; + if (strlen(name) > 255) + return -ERANGE; + down_read(&EXT4_I(inode)->xattr_sem); error = ext4_xattr_ibody_get(inode, name_index, name, buffer, buffer_size); @@ -1073,8 +1076,6 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, unsigned long no_expand; int error; - if (!name) - return -EINVAL; if (strlen(name) > 255) return -ERANGE; down_write(&EXT4_I(inode)->xattr_sem);
In ext4_xattr_set_handle() we have checked the xattr name's length. So we should also check it in ext4_xattr_get() to avoid unneeded lookup caused by invalid name. In addition, we deleted the check of NULL in ext4_xattr_set_handle(), because in all the callers of the ext4_xattr_set_handle(), the name can't be NULL. Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> --- fs/ext4/xattr.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)