In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102 A call to listxattr() with a buffer size = 0 returns the actual size …

Summary

In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102 A call to listxattr() with a buffer size = 0 returns the actual size of the buffer needed for a subsequent call. When size > 0, nfs4_listxattr() does not return an error because either generic_listxattr() or nfs4_listxattr_nfs4_label() consumes exactly all the bytes then size is 0 when calling nfs4_listxattr_nfs4_user() which then triggers the following kernel BUG: …