9 Nov
2021
9 Nov
'21
4:26 p.m.
On Tue, Nov 09, 2021 at 12:48:41PM +0100, Jan Kara wrote:
udf_readdir() didn't validate the directory position it should start reading from. Thus when user uses lseek(2) on directory file descriptor it can trick udf_readdir() into reading from a position in the middle of directory entry which then upsets directory parsing code resulting in errors or even possible kernel crashes. Similarly when the directory is modified between two readdir calls, the directory position need not be valid anymore.
... We don't have an xfstest for this already? Actually, two. One for lseek() and one for modifying the directory as it's being read.