From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B080F206E97 for ; Wed, 6 Nov 2024 17:09:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730912979; cv=none; b=rctnROkSfF42rxcVdOyA80abcX2VdzBp7sQnKqEtqRsmgnI1XypTNCbm3n/ZCygTa/FO390ueBGsTsCBAG+odyY7Oqd0NYfZXunE6hYalXmerO+m05WTbxi+iVqYW+mf2Y9OI+aqnchvsXB6rkUHVikXPfe1fiLhf/N8YtUn0FI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730912979; c=relaxed/simple; bh=xA46enblRv87qqgY+6DG4GGjINcLxdFJ2E81K3yFp1Q=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ZI0Fz7oGXhh8VVtfg7/X6eG5JD8VbLwy8KvfhDdIBOGUoBSBxyxeoha+mzof7DGp3hF1EQbwydrK87Ul6Wn7Gbc+szlQQpdZIV9KdUJjrFzLhQtfBhtauAxQ05paQis7GyPe/B6Yc13FqY0EzoKIBJimHhy/2DgxfKLip48clrU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--surenb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=IkOziWLX; arc=none smtp.client-ip=209.85.128.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--surenb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IkOziWLX" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6e3c638cc27so133858547b3.0 for ; Wed, 06 Nov 2024 09:09:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1730912977; x=1731517777; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Bu/tCa/EAr7v3VimsEZAuyq+f/De3I1ag0mzO42VO34=; b=IkOziWLXJhZMWtwv9ZdgyH7CRj59CftJNqGV3CwHIpn6/i3y8a5321UvIkpf+Paf7W lD8P+dD36LbktpW2M45dtl5tZAGDifR0MXsdE0crLYNIzhIdQVJMKz2mfDEj/Zw3ujQ2 iK+xT0672vB72/hfcCIa8ftR9jj5qwO6geV1aDrZsVNAu2IBMrgVn0G9T82L8l+PeBw3 f6xIfvYN3ziiySCKBxrLwyU850TrYMAJbkMPabNk1K7fsJ/TKvLQ2LZycbcacscRyu/T 57m/xEz1GmTqTTh5MKRPQk67n2SCQAPLBeldqNgIgRUcfo36HkD93HwrQ9yKrthAWI5Q LSzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730912977; x=1731517777; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Bu/tCa/EAr7v3VimsEZAuyq+f/De3I1ag0mzO42VO34=; b=b9G6ogD9h05m0DoV5NtYeMKPrXceuge6wRRnNbkG5lUjAxyUbuMHgagNBVCskpwYTk LG09CJXu7pT/HClHy7K1TRTt1sv0GQgzJsw8No3rYbs5jmZTPXH/f1omjQY+YOcnYSUO KdyQD/h+G4pgY94v1i0VHTqCzqO2ZVFRbBe8Cv/DjYT6P+Byb2u4khpszZmhdjQ8zL1a ZjJWFfTlOqtNzzM9WNFuiaoRM1/7KgZBxiQgZaUZUQcK43thcbWC9HAdLIH1JXTK35+4 IkgCgTpN5tCT1gQiZYijdiAswElg7cHZpcd2dQFFG1rzuG6Hsa7lhtIzP8DqYGqHOCOF W+oA== X-Forwarded-Encrypted: i=1; AJvYcCX1lxqyWV+xiWoikM61E99789RNMnfNDMOhqsfhIOK9VZdu1iRqIRS1prr6K7ojzzZ6YCOqAw8=@vger.kernel.org X-Gm-Message-State: AOJu0YydrNfZsNMTW3KeNn+H37lIndy9b7tGuus+Kb38TBSKskybCanB 8KubvsS76nmGghlNOsuL0ATD7HYt+MyK/3cA5HZh7T5j/lBLtWc3H08D1/pragKKFWIFASLiHyL MpA== X-Google-Smtp-Source: AGHT+IEY4RXzcMsI17paV2X954YMaF2/EsO1zNFX2pQquk3V89jRarHNwbd5OKr7TLIt7VnEo7QyiX0TO5s= X-Received: from surenb-desktop.mtv.corp.google.com ([2a00:79e0:2e3f:8:b9c:a9f1:f265:18b4]) (user=surenb job=sendgmr) by 2002:a05:690c:3688:b0:6db:c6ac:62a0 with SMTP id 00721157ae682-6e9d8bced01mr12256367b3.5.1730912976654; Wed, 06 Nov 2024 09:09:36 -0800 (PST) Date: Wed, 6 Nov 2024 09:09:27 -0800 In-Reply-To: <20241106170927.130996-1-surenb@google.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241106170927.130996-1-surenb@google.com> X-Mailer: git-send-email 2.47.0.199.ga7371fff76-goog Message-ID: <20241106170927.130996-2-surenb@google.com> Subject: [PATCH v2 6.11.y 2/2] lib: alloc_tag_module_unload must wait for pending kfree_rcu calls From: Suren Baghdasaryan To: gregkh@linuxfoundation.org Cc: akpm@linux-foundation.org, fw@strlen.de, urezki@gmail.com, vbabka@suse.cz, greearb@candelatech.com, kent.overstreet@linux.dev, surenb@google.com, stable@vger.kernel.org, patches@lists.linux.dev Content-Type: text/plain; charset="UTF-8" From: Florian Westphal commit dc783ba4b9df3fb3e76e968b2cbeb9960069263c upstream. Ben Greear reports following splat: ------------[ cut here ]------------ net/netfilter/nf_nat_core.c:1114 module nf_nat func:nf_nat_register_fn has 256 allocated at module unload WARNING: CPU: 1 PID: 10421 at lib/alloc_tag.c:168 alloc_tag_module_unload+0x22b/0x3f0 Modules linked in: nf_nat(-) btrfs ufs qnx4 hfsplus hfs minix vfat msdos fat ... Hardware name: Default string Default string/SKYBAY, BIOS 5.12 08/04/2020 RIP: 0010:alloc_tag_module_unload+0x22b/0x3f0 codetag_unload_module+0x19b/0x2a0 ? codetag_load_module+0x80/0x80 nf_nat module exit calls kfree_rcu on those addresses, but the free operation is likely still pending by the time alloc_tag checks for leaks. Wait for outstanding kfree_rcu operations to complete before checking resolves this warning. Reproducer: unshare -n iptables-nft -t nat -A PREROUTING -p tcp grep nf_nat /proc/allocinfo # will list 4 allocations rmmod nft_chain_nat rmmod nf_nat # will WARN. Link: https://lkml.kernel.org/r/20241007205236.11847-1-fw@strlen.de Fixes: a473573964e5 ("lib: code tagging module support") Signed-off-by: Florian Westphal Reported-by: Ben Greear Closes: https://lore.kernel.org/netdev/bdaaef9d-4364-4171-b82b-bcfc12e207eb@candelatech.com/ Cc: Uladzislau Rezki Cc: Vlastimil Babka Cc: Suren Baghdasaryan Cc: Kent Overstreet Cc: Signed-off-by: Andrew Morton Signed-off-by: Suren Baghdasaryan --- Changes since v1 [1]: - Added SOB, per Greg KH [1] https://lore.kernel.org/all/20241021171003.2907935-2-surenb@google.com/ lib/codetag.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/codetag.c b/lib/codetag.c index afa8a2d4f317..d1fbbb7c2ec3 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -228,6 +228,9 @@ bool codetag_unload_module(struct module *mod) if (!mod) return true; + /* await any module's kfree_rcu() operations to complete */ + kvfree_rcu_barrier(); + mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { struct codetag_module *found = NULL; -- 2.47.0.199.ga7371fff76-goog