On Mon, Jun 11, 2018 at 07:36:48PM +0000, Xu, Wen wrote: > When mounting a crafted xfs v4 image, the kernel hangs and never returns for mount operation. Suspect potential deadlock in log recovery exists. Not sure it is considered as a bug or not. > > - Reproduce (on 4.17 upstream kernel) > # mkdir mnt > # mount -t xfs 0.img mnt > > The image file (0.img.zip) is available here: https://bugzilla.kernel.org/attachment.cgi?id=276475 So it's a filesystem with a log that has bit corruptions in it's log record headers, and log CRCs are turned off. All kernels since late 2012 have CRC'd log records for both v4 and v5 filesystems. Hence any remotely recent kernel faced wih bit errors in the journal are going to behave differently - corruption warnings will be issued first, and while v4 filesystems will continue to try to mount, a v5 filesystem will refuse to mount. And kernels old enough not to CRC log records are unlikely to ever get bug fixes for maliciously corrupted log records. As such, I'm going to consider this a low priority right now. Protecting log recovery against anything more than random bit errors is a fairly major undertaking, and not something I plan on doing in the near term... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
