On 06/12/2014 11:27 PM, Dan Aloni wrote: > On Thu, Jun 12, 2014 at 10:56:16PM -0400, Sasha Levin wrote: >> > Hi all, >> > >> > Okay, I'm really lost. I got the following when fuzzing, and can't really >> > explain what's >> > going on. It seems that we get a "unable to handle kernel paging request" >> > when running >> > rather simple code, and I can't figure out how it would cause it. > [..] >> > Which agrees with the trace I got: >> > >> > [ 516.309720] BUG: unable to handle kernel paging request at >> > ffffffffa0f12560 >> > [ 516.309720] IP: netlink_getsockopt (net/netlink/af_netlink.c:2271) > [..] >> > [ 516.309720] RIP netlink_getsockopt (net/netlink/af_netlink.c:2271) >> > [ 516.309720] RSP <ffff8803fc85fed8> >> > [ 516.309720] CR2: ffffffffa0f12560 >> > >> > They only theory I had so far is that netlink is a module, and has gone >> > away while the code >> > was executing, but netlink isn't a module on my kernel. > The RIP - 0xffffffffa0f12560 is in the range (from > Documentation/x86/x86_64/mm.txt): > > ffffffffa0000000 - ffffffffff5fffff (=1525 MB) module mapping space > > So seems it was in a module.
Yup, that's why that theory came up, but when I checked my config: $ cat .config | grep NETLINK CONFIG_COMPAT_NETLINK_MESSAGES=y CONFIG_NETFILTER_NETLINK=y CONFIG_NETFILTER_NETLINK_ACCT=y CONFIG_NETFILTER_NETLINK_QUEUE=y CONFIG_NETFILTER_NETLINK_LOG=y CONFIG_NF_CT_NETLINK=y CONFIG_NF_CT_NETLINK_TIMEOUT=y CONFIG_NF_CT_NETLINK_HELPER=y CONFIG_NETFILTER_NETLINK_QUEUE_CT=y CONFIG_NETLINK_MMAP=y CONFIG_NETLINK_DIAG=y CONFIG_SCSI_NETLINK=y CONFIG_QUOTA_NETLINK_INTERFACE=y that theory went away. (also confirmed by not finding a netlink module.) What about the kernel .text overflowing into the modules space? The loader checks for that, but can something like that happen after everything is up and running? I'll look into that tomorrow. Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
