On 17 Nov 2008 at 13:44, Pablo Neira Ayuso wrote: > > ok, here's the rest of the story: > > > > (gdb) x/16x $sp > > 0x7fffffffb398: 0xf7ba28b5 0x00007fff 0x00000001 0x00000000 > > (gdb) x/8i 0x00007ffff7ba28b5-3 > > 0x7ffff7ba28b2 <__build_protoinfo+450>: callq *(%rdx,%rax,8) > > 0x7ffff7ba28b5 <__build_protoinfo+453>: mov $0x1,%eax > > 0x7ffff7ba28ba <__build_protoinfo+458>: mov %ebp,%ecx > > 0x7ffff7ba28bc <__build_protoinfo+460>: shl %cl,%rax > > 0x7ffff7ba28bf <__build_protoinfo+463>: or %eax,(%r14,%rbx,4) > > 0x7ffff7ba28c3 <__build_protoinfo+467>: cmp $0x37,%r12d > > 0x7ffff7ba28c7 <__build_protoinfo+471>: jle 0xfffffffff7ba287f > > 0x7ffff7ba28c9 <__build_protoinfo+473>: mov 0x10(%rsp),%rdx > > (gdb) i r rdx rax > > rdx 0x7ffff7db5000 140737351733248 > > rax 0x37 55 > > (gdb) x/8x $rdx+8*$rax > > 0x7ffff7db51b8: 0x00000000 0x00000000 0xf7ba9468 0x00007fff > > 0x7ffff7db51c8: 0xf7ba94b1 0x00007fff 0xf7ba9505 0x00007fff > > > > so that's a null function pointer in whatever structure __build_protoinfo dereferences > > there. is it of any help to you or do you need me to dig out more? > > Hm, that code belongs to libnetfilter_conntrack (src/conntrack/build.c). > The annoying thing is that I see no structure with function pointers in > that piece of bits. There are only calls to libnfnetlink functions to > build the netlink message that is sent to kernel-space. sorry, gdb used the wrong symbols, i decoded it by hand now and the failing code is nfct_copy calling through copy_attr_array[] and it so happens that the array has no function defined for index ATTR_HELPER_NAME, the last entry in enum nf_conntrack_attr so i guess it was added without the person being aware of its uses elsewhere... maybe check your tree for similar issues and also add some big fat comment to the enum definition to remind yourselves to update other places when adding a new enum there ;) -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
