Re: [PATCH] netfs: Fix UAF in netfs_unbuffered_write() on failed preparation

[David Howells]

ChenXiaoSong <chenxiaosong@xxxxxxxxxxxxxxxx> wrote:

> After applying this patch, I can still reproduce the use-after-free issue.

Can you get some tracing?  I have a suspicion it's a refcount bug.

The following tracepoints would be useful:

echo 1 > /sys/kernel/tracing/events/netfs/netfs_read/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_write/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_rreq/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_sreq/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_failure/enable
echo 1 > /sys/kernel/tracing/events/error_report/enable

And if you can capture this, can you compress the resulting trace and send it
to me?

Thanks,
David