On 9/12/21 10:41 PM, Christoph Hellwig wrote:
Al pointed out multiple times that seq_get_buf is highly dangerous as it opens up the tight seq_file abstractions to buffer overflows. The last such caller now is sysfs. This series allows attributes to implement a seq_show method and switch the block and XFS code as users that I'm most familiar with to use seq_files directly after a few preparatory cleanups. With this series "leaf" users of sysfs_ops can be converted one at at a time, after that we can move the seq_get_buf into the multiplexers (e.g. kobj, device, class attributes) and remove the show method in sysfs_ops and repeat the process until all attributes are converted. This will probably take a fair amount of time.
Hi Christoph, Thanks for having done this work. In case you would need it, some time ago I posted the following sysfs patch but did not receive any feedback: "[PATCH] kernfs: Improve lockdep annotation for files which implement mmap" (https://lore.kernel.org/linux-kernel/20191004161124.111376-1-bvanassche@xxxxxxx/). Bart.
