Re: inbound connection problems when "netlink: test for all flags of the NLM_F_DUMP composite" commit applied

[Eric Dumazet <eric.dumazet@gmail.com>]

Le dimanche 16 janvier 2011 à 19:24 +1030, Arthur Marsh a écrit :

CC people involved with the commit

> 
>  
>  This bug was originally posted at https://bugzilla.kernel.org/show_bug.cgi?id=26632 
> 
> With kernels up to and including 2.6.37-git7, inbound telnetd-ssl connections worked fine. 
> With kernel 2.6.37-git9 and later inbound telnetd-ssl connections failed, and on machine shut-down, there were warning messages about daemons not return status. 
>  
> A git bisect on Linus' kernel tree revealed: 
>  
> 0ab03c2b1478f2438d2c80204f7fef65b1bca9cf is the first bad commit 
> commit 0ab03c2b1478f2438d2c80204f7fef65b1bca9cf 
> Author: Jan Engelhardt <jengelh@medozas.de> 
> Date:   Fri Jan 7 03:15:05 2011 +0000 
>  
>     netlink: test for all flags of the NLM_F_DUMP composite 
>  
>     Due to NLM_F_DUMP is composed of two bits, NLM_F_ROOT | NLM_F_MATCH, 
>     when doing "if (x & NLM_F_DUMP)", it tests for _either_ of the bits 
>     being set. Because NLM_F_MATCH's value overlaps with NLM_F_EXCL, 
>     non-dump requests with NLM_F_EXCL set are mistaken as dump requests. 
>  
>     Substitute the condition to test for _all_ bits being set. 
>  
>     Signed-off-by: Jan Engelhardt <jengelh@medozas.de> 
>     Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> 
>     Signed-off-by: David S. Miller <davem@davemloft.net> 
>  
> :040000 040000 1a0717ab0c87787309c3c3af88d666b44f327f64 
> cba6279de85b7ebeaf21f19f1d93b59468fdd01d M      net 
>  
> I tried git cherry-pick 0ab03c2b1478f2438d2c80204f7fef65b1bca9cf and verified 
> that the resulting kernel had these problems, then git revert 
> 0ab03c2b1478f2438d2c80204f7fef65b1bca9cf and verified that the resulting kernel 
> did *not* have problems. 
>  
> Arthur.