On Sun, May 29, 2022 at 12:57:59PM +0000, Schroeder, Julian wrote:
From: Julian Schroeder jumaco@amazon.com Date: Fri, 20 May 2022 18:33:27 +0000 Subject: [PATCH] nfsd: destroy percpu stats counters after reply cache shutdown MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Upon nfsd shutdown any pending DRC cache is freed. DRC cache use is tracked via a percpu counter. In the current code the percpu counter is destroyed before. If any pending cache is still present, percpu_counter_add is called with a percpu counter==NULL. This causes a kernel crash. The solution is to destroy the percpu counter after the cache is freed. Fixes: e567b98ce9a4b (âEURoenfsd: protect concurrent access to nfsd stats countersâEUR) Signed-off-by: Julian Schroeder jumaco@amazon.com
fs/nfsd/nfscache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 0b3f12aa37ff..7da88bdc0d6c 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -206,7 +206,6 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn) struct svc_cacherep *rp; unsigned int i;
nfsd_reply_cache_stats_destroy(nn); unregister_shrinker(&nn->nfsd_reply_cache_shrinker); for (i = 0; i < nn->drc_hashsize; i++) {@@ -217,6 +216,7 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn) rp, nn); } }
nfsd_reply_cache_stats_destroy(nn); kvfree(nn->drc_hashtbl); nn->drc_hashtbl = NULL;-- 2.32.0
What is the git commit id of this in Linus's tree?
And this patch is totally damaged with whitespace and can not be applied at all :(
Please fix it up and submit it again.
thanks,
greg k-h
The patch made it into linux next. commit fd5e363eac77e. I sent the patch to stable again via git send-email (https://www.spinics.net/lists/stable/msg560818.html)
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
Upon nfsd shutdown any pending DRC cache is freed. DRC cache use is tracked via a percpu counter. In the current code the percpu counter is destroyed before. If any pending cache is still present, percpu_counter_add is called with a percpu counter==NULL. This causes a kernel crash. The solution is to destroy the percpu counter after the cache is freed.
Fixes: e567b98ce9a4b (“nfsd: protect concurrent access to nfsd stats counters”) Signed-off-by: Julian Schroeder jumaco@xxxxxxxxxx
That is a very odd email address :(
Again, as the document says, just wait until a commit is in Linus's tree and then send us the git commit id.
thanks,
greg k-h