Date: Mon, 10 Dec 2012 15:21:44 -0800 From: Adrian Chadd <adrian@freebsd.org> To: mdf@freebsd.org Cc: Garrett Cooper <yanegomi@gmail.com>, freebsd-net@freebsd.org, FreeBSD Current <freebsd-current@freebsd.org> Subject: Re: "Memory modified after free" - by whom? Message-ID: <CAJ-Vmok2C_hWd4sDzoVLNWuAzgeP9Cmv6VNfcikDogG_rw8JYg@mail.gmail.com> In-Reply-To: <CAMBSHm96ZEiF4mOhUyk-aDS%2BGs%2BhDsh_dMsd-WFcmZ%2BSm6Zk%2BA@mail.gmail.com> References: <CAGH67wQKUDLQmL8cnWwgzQpWAN2OhKLu0AemPNuy7EOC-i1p9g@mail.gmail.com> <CAJ-Vmo=MsSV3DhAVEP36d%2BFccHDdQz7%2By7v5xTjYKyBP0PfQoQ@mail.gmail.com> <CAMBSHm96ZEiF4mOhUyk-aDS%2BGs%2BhDsh_dMsd-WFcmZ%2BSm6Zk%2BA@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 10 December 2012 15:18, <mdf@freebsd.org> wrote: > On Mon, Dec 10, 2012 at 3:10 PM, Adrian Chadd <adrian@freebsd.org> wrote: >> 9216 sounds like a jumbo frame mbuf. So the NIC is writing to an mbuf >> after it's finalised/freed. >> >> I have a similar bug showing up on ath(4) RX. :( > > Compile with DEBUG_MEMGUARD in the kernel configuration, and then set > vm.memguard.desc to the name of the UMA zone used for the 9216 byte > allocations, mbuf_jumbo_9k. This should cause a panic when the memory > is touched after free. Right, but I think its a _hardware_ access after the buffer has been freed.. Adrian
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAJ-Vmok2C_hWd4sDzoVLNWuAzgeP9Cmv6VNfcikDogG_rw8JYg>