Re: dns_resolver_preparse tries to print arbitrarily-large user-provided strings

2018-02-27 Thread Eric Biggers
Hi Mark, On Tue, Feb 27, 2018 at 04:43:13PM +, Mark Rutland wrote: > Hi, > > As a heads-up, while fuzzing v4.16-rc3 on arm64 with Syzkaller, I hit a > system hang which I was able to minize to the reproducer below. It looks > like the system hang is an artifact of Syzkaller using

dns_resolver_preparse tries to print arbitrarily-large user-provided strings

2018-02-27 Thread Mark Rutland
Hi, As a heads-up, while fuzzing v4.16-rc3 on arm64 with Syzkaller, I hit a system hang which I was able to minize to the reproducer below. It looks like the system hang is an artifact of Syzkaller using panic_on_warn, as dns_resolver_preparse can trigger a WARN_ONCE() in the bowels of printk(),