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authorFlorian Westphal <fw@strlen.de>2014-03-06 18:06:41 +0100
committerJiri Slaby <jslaby@suse.cz>2014-04-18 11:06:57 +0200
commitd291aa322b32aa808e914996c7f234024e53432d (patch)
treed4b3c7d23eb092415fcf5084ed322e2ed83bdf01
parentd80441c0019881e72774fa3f51a09997b8214a46 (diff)
inet: frag: make sure forced eviction removes all frags
[ Upstream commit e588e2f286ed7da011ed357c24c5b9a554e26595 ] Quoting Alexander Aring: While fragmentation and unloading of 6lowpan module I got this kernel Oops after few seconds: BUG: unable to handle kernel paging request at f88bbc30 [..] Modules linked in: ipv6 [last unloaded: 6lowpan] Call Trace: [<c012af4c>] ? call_timer_fn+0x54/0xb3 [<c012aef8>] ? process_timeout+0xa/0xa [<c012b66b>] run_timer_softirq+0x140/0x15f Problem is that incomplete frags are still around after unload; when their frag expire timer fires, we get crash. When a netns is removed (also done when unloading module), inet_frag calls the evictor with 'force' argument to purge remaining frags. The evictor loop terminates when accounted memory ('work') drops to 0 or the lru-list becomes empty. However, the mem accounting is done via percpu counters and may not be accurate, i.e. loop may terminate prematurely. Alter evictor to only stop once the lru list is empty when force is requested. Reported-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de> Reported-by: Alexander Aring <alex.aring@gmail.com> Tested-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-rw-r--r--net/ipv4/inet_fragment.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index e15fb7b2db59..12b80fbfe767 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -211,7 +211,7 @@ int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force)
}
work = frag_mem_limit(nf) - nf->low_thresh;
- while (work > 0) {
+ while (work > 0 || force) {
spin_lock(&nf->lru_lock);
if (list_empty(&nf->lru_list)) {