From: Florian Westphal <fw@xxxxxxxxx> Date: Tue, 30 May 2017 11:38:12 +0200 > Quoting Joe Stringer: > If a user loads nf_conntrack_ftp, sends FTP traffic through a network > namespace, destroys that namespace then unloads the FTP helper module, > then the kernel will crash. > > Events that lead to the crash: > 1. conntrack is created with ftp helper in netns x > 2. This netns is destroyed > 3. netns destruction is scheduled > 4. netns destruction wq starts, removes netns from global list > 5. ftp helper is unloaded, which resets all helpers of the conntracks > via for_each_net() > > but because netns is already gone from list the for_each_net() loop > doesn't include it, therefore all of these conntracks are unaffected. > > 6. helper module unload finishes > 7. netns wq invokes destructor for rmmod'ed helper > > CC: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> > Reported-by: Joe Stringer <joe@xxxxxxx> > Signed-off-by: Florian Westphal <fw@xxxxxxxxx> > --- > Eric, I'd like an explicit (n)ack from you for this one. Indeed, Eric, please do. Otherwise I'm fine with the generic parts: Acked-by: David S. Miller <davem@xxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
