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b=FCWhKPr+x/+OaHV3MpHuliUX7bbExsb2uYJYnKRtVWVy4rl0Nv8eVMX24Xbq19L9o AAnb3kFvhj2UigzwT9nWAugGbRwWKuiAwz8lsknVS1eItkpd3oFKo9YG6WSsTdAM7L FZI2jBVtYW1kqjslfJJtvI+qEGwq5SjujJ4ofF4o= Date: Sun, 26 Apr 2026 03:49:38 -0700 From: Andrew Morton To: syzbot Cc: Liam.Howlett@oracle.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, shakeel.butt@linux.dev, surenb@google.com, syzkaller-bugs@googlegroups.com, vbabka@kernel.org, Muchun Song , Qi Zheng Subject: Re: [syzbot] [mm?] WARNING: bad unlock balance in do_wp_page Message-Id: <20260426034938.db29d74982a8eb8463f8cf3a@linux-foundation.org> In-Reply-To: <69edca15.170a0220.38e3f1.0000.GAE@google.com> References: <69edca15.170a0220.38e3f1.0000.GAE@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 4F6A0180004 X-Stat-Signature: yf7xqryqajyntejy9r44t7bfwipm8rum X-HE-Tag: 1777200581-786939 X-HE-Meta: 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 RNumpOF6 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, 26 Apr 2026 01:17:25 -0700 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 6596a02b2078 Merge tag 'drm-next-2026-04-22' of https://gi.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=12483702580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=24c8da4692f901cb > dashboard link: https://syzkaller.appspot.com/bug?extid=7d60b33a8a546263da7c > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 > userspace arch: i386 > > Unfortunately, I don't have any reproducer for this issue yet. argh, that dreaded sentence. Thanks. Something's definitely amiss. This is at least the fifth report of rcu_read_lock() imbalance post-7.0. Others: https://lore.kernel.org/69eab803.a00a0220.17a17.004a.GAE@google.com https://lore.kernel.org/69eab803.a00a0220.17a17.004b.GAE@google.com https://lore.kernel.org/69eafb0e.a00a0220.9259.0031.GAE@google.com https://lore.kernel.org/69ebcbe2.a00a0220.7773.0005.GAE@google.com In some cases we released it too often, in other cases we failed to release it. The first one is slightly more useful in that it tells us that the not-released rcu_read_lock() was taken in folio_lruvec_lock_irqsave(). Muchun & Qi: you played with that rcu locking in 31b54a5e8916. Can you please double-check that we didn't miss something?