On 10/12/19 7:51 AM, Markus Elfring wrote: > Hello, > > I tried another script for the semantic patch language out. > This source code analysis approach points out that the implementation > of the function “tcp_time_wait” contains also a call of the function “kmemdup”. > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/ipv4/tcp_minisocks.c?id=1c0cc5f1ae5ee5a6913704c0d75a6e99604ee30a#n306 > https://elixir.bootlin.com/linux/v5.4-rc2/source/net/ipv4/tcp_minisocks.c#L306 > > * Do you find the usage of the macro call “BUG_ON” still appropriate at this place? > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/checkpatch.pl?id=1c0cc5f1ae5ee5a6913704c0d75a6e99604ee30a#n4080 > > * Is there a need to adjust the error handling here? Presumably the BUG would trigger if a really disturbing bug happened. There is no chance a timewait socket could be created with a MD5 key, if the established socket that is the 'parent' of the timewait has not a MD5 context itself. The parent socket only could have MD5 context if tcp_md5sig_pool_populated could have been set to true. Once tcp_md5sig_pool_populated is true it can never go back to false. So the bug here would be that a socket had a successful MD5 context, and following tcp_alloc_md5sig_pool() would return false. We can discuss of all BUG() in general, some people simply disable all of them (cf CONFIG_BUG), but this particular one does not seem specially bad to me, compared to others.
