David Miller <davem@xxxxxxxxxxxxx> writes: > 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. Taking a look now. The original didn't make it's way into my inbox. I just have a copy from netdev. Florian there may be a bit of an email black hole between us. > Otherwise I'm fine with the generic parts: > > Acked-by: David S. Miller <davem@xxxxxxxxxxxxx> Eric -- 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
