From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f69.google.com (mail-oo1-f69.google.com [209.85.161.69]) (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 78D593B19C9 for ; Thu, 19 Mar 2026 21:36:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773956177; cv=none; b=CZ8c97DePjEfE1gN/CmrqD866eWxrqYgrGuXZJNI0UZCjFqm3qfQkLBjFysjZzCMhcds3aazTkjOx2cz114EXmKjTwN3Nipz+YuzVB3gY/o6lPRM5QiorWMnZNYjbwxIYdnFcn60yl++NKoaBMJKa4mSy3G4XInG3YIf3afglhM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773956177; c=relaxed/simple; bh=iYv+0JMBhL0Y3n+y6pJw/rt2uBkC/RlMI6Ep70XgoGw=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=rv6LAjgPy9L9t6m1lDRdAA4F7Ho2efLaNNkjpqNV3yiF6cHv1J+3YtzU0b8HvgjQciHNq6gCBX8fFZpjKW2tbD3XCtPw4GNkO/nkfn0VQATgQ+o8VsbkOSHxz/l6j2zA/JaR0PSVnUPOsuNgek6jQ4QmlFSL+htValnKDOcoADQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f69.google.com with SMTP id 006d021491bc7-66308f16ea1so17918089eaf.2 for ; Thu, 19 Mar 2026 14:36:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773956175; x=1774560975; h=cc:to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ynbncJsLJEK7RgBrfoH+8cd27pvPqD1p1MxcDbeHsxs=; b=ISZvGuxGr4U5rXnL1GsqWLcd+X1Fl+o71dmfKjupvoxzKixhbntYXcyHEPDQG0PxtJ LDqLGcm6Ghd8yxLdXEx8aSCcnc16va9xpk72mz6NLzZPaSRHQYWHCVY/o/x2u6QaxbDL LfWJSNwBOCN7i05zNOA6UMHe1vfUcTYrOO4V2419kaxX3UIRjkXnDuGR0mDu2pdBwgss HMUmXbOoNSsnOIR2JpwCE+ReSdHE1dcnfBagxBZcztsvQS86ISrcvcmMPBcftiQSpJDA gGhuRYBCI5bki+eJXhi1ZOZ+XZaWFAZNlGTn91IhV+FK8XvwXZOU/5trVYoZYJbuwOK0 xMSQ== X-Forwarded-Encrypted: i=1; AJvYcCUBM/bf+0YiioIklDXae9guL2iVSNUW5EVStcPA2rwG0WeoaNDD0HwwNDVvqyDSZ5dl4OHuAwrvTq0=@vger.kernel.org X-Gm-Message-State: AOJu0YyV6hZfkcL6wSjDmVVc5mjcPiioXPLu7BYMYsBhdQQJNL0EqYJA srjVhkhUjHsyTRtYeerwP4xkXr6AJHDdEOwtYenXRMVbpz9A9QNWyXFP2QipZqljxyX+qmSpMKL TSwDzUD5rf2zy4lAJwwRjOqBX5pNaRnKnhe6hjqUO9A9zsIuZQpQgQLEMS0Q= Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:3104:b0:67b:a667:f51f with SMTP id 006d021491bc7-67c22bcbc3emr753879eaf.6.1773956175475; Thu, 19 Mar 2026 14:36:15 -0700 (PDT) Date: Thu, 19 Mar 2026 14:36:15 -0700 In-Reply-To: <20260318222953.441758-1-nphamcs@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69bc6c4f.050a0220.3bf4de.0001.GAE@google.com> Subject: [syzbot ci] Re: Virtual Swap Space From: syzbot ci To: akpm@linux-foundation.org, apopple@nvidia.com, axelrasmussen@google.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, bhe@redhat.com, byungchul@sk.com, cgroups@vger.kernel.org, chengming.zhou@linux.dev, chrisl@kernel.org, corbet@lwn.net, david@kernel.org, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jannh@google.com, joshua.hahnjy@gmail.com, kasong@tencent.com, kernel-team@meta.com, lance.yang@linux.dev, lenb@kernel.org, liam.howlett@oracle.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, lorenzo.stoakes@oracle.com, matthew.brost@intel.com, mhocko@suse.com, muchun.song@linux.dev, npache@redhat.com, nphamcs@gmail.com, pavel@kernel.org, peterx@redhat.com, peterz@infradead.org, pfalcato@suse.de, rafael@kernel.org, rakie.kim@sk.com, riel@surriel.com, roman.gushchin@linux.dev, rppt@kernel.org, ryan.roberts@arm.com, shakeel.butt@linux.dev, shikemeng@huaweicloud.com, surenb@google.com, tglx@kernel.org, vbabka@suse.cz, weixugc@google.com, ying.huang@linux.alibaba.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v4] Virtual Swap Space https://lore.kernel.org/all/20260318222953.441758-1-nphamcs@gmail.com * [PATCH v4 01/21] mm/swap: decouple swap cache from physical swap infrastructure * [PATCH v4 02/21] swap: rearrange the swap header file * [PATCH v4 03/21] mm: swap: add an abstract API for locking out swapoff * [PATCH v4 04/21] zswap: add new helpers for zswap entry operations * [PATCH v4 05/21] mm/swap: add a new function to check if a swap entry is in swap cached. * [PATCH v4 06/21] mm: swap: add a separate type for physical swap slots * [PATCH v4 07/21] mm: create scaffolds for the new virtual swap implementation * [PATCH v4 08/21] zswap: prepare zswap for swap virtualization * [PATCH v4 09/21] mm: swap: allocate a virtual swap slot for each swapped out page * [PATCH v4 10/21] swap: move swap cache to virtual swap descriptor * [PATCH v4 11/21] zswap: move zswap entry management to the virtual swap descriptor * [PATCH v4 12/21] swap: implement the swap_cgroup API using virtual swap * [PATCH v4 13/21] swap: manage swap entry lifecycle at the virtual swap layer * [PATCH v4 14/21] mm: swap: decouple virtual swap slot from backing store * [PATCH v4 15/21] zswap: do not start zswap shrinker if there is no physical swap slots * [PATCH v4 16/21] swap: do not unnecesarily pin readahead swap entries * [PATCH v4 17/21] swapfile: remove zeromap bitmap * [PATCH v4 18/21] memcg: swap: only charge physical swap slots * [PATCH v4 19/21] swap: simplify swapoff using virtual swap * [PATCH v4 20/21] swapfile: replace the swap map with bitmaps * [PATCH v4 21/21] vswap: batch contiguous vswap free calls and found the following issue: possible deadlock in vswap_iter Full report is available here: https://ci.syzbot.org/series/f8238a2a-370e-404d-b3f7-5945b574bd63 *** possible deadlock in vswap_iter tree: bpf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git base: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/cf1517a6-d391-46d8-bfbe-98e6be6b93ce/config syz repro: https://ci.syzbot.org/findings/b4e84ae7-17d4-4bf8-9c3f-4c13b10a1e52/syz_repro ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.1.18/6001 is trying to acquire lock: ffff88811fba0018 (&cluster->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88811fba0018 (&cluster->lock){+.+.}-{3:3}, at: vswap_iter+0xfa/0x1b0 mm/vswap.c:274 but task is already holding lock: ffff88811fba0018 (&cluster->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff88811fba0018 (&cluster->lock){+.+.}-{3:3}, at: swap_cache_lock_irq+0xe2/0x190 mm/vswap.c:1529 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&cluster->lock); lock(&cluster->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz.1.18/6001: #0: ffff8881bb523440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:391 [inline] #0: ffff8881bb523440 (&mm->mmap_lock){++++}-{4:4}, at: madvise_lock+0x152/0x2e0 mm/madvise.c:1789 #1: ffff88811fba0018 (&cluster->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #1: ffff88811fba0018 (&cluster->lock){+.+.}-{3:3}, at: swap_cache_lock_irq+0xe2/0x190 mm/vswap.c:1529 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: vswap_cgroup_record+0x41/0x440 mm/vswap.c:1909 stack backtrace: CPU: 0 UID: 0 PID: 6001 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] vswap_iter+0xfa/0x1b0 mm/vswap.c:274 vswap_cgroup_record+0xeb/0x440 mm/vswap.c:1910 swap_cgroup_record+0xc5/0x130 mm/vswap.c:1933 memcg1_swapout+0x358/0x9e0 mm/memcontrol-v1.c:623 __remove_mapping+0x7d4/0xa70 mm/vmscan.c:762 shrink_folio_list+0x287c/0x5160 mm/vmscan.c:1518 reclaim_folio_list+0x100/0x400 mm/vmscan.c:2198 reclaim_pages+0x45b/0x530 mm/vmscan.c:2235 madvise_cold_or_pageout_pte_range+0x1eac/0x2220 mm/madvise.c:444 walk_pmd_range mm/pagewalk.c:130 [inline] walk_pud_range mm/pagewalk.c:224 [inline] walk_p4d_range mm/pagewalk.c:262 [inline] walk_pgd_range+0x1032/0x1d30 mm/pagewalk.c:303 __walk_page_range+0x14c/0x710 mm/pagewalk.c:410 walk_page_range_vma_unsafe+0x309/0x410 mm/pagewalk.c:714 madvise_pageout_page_range mm/madvise.c:622 [inline] madvise_pageout mm/madvise.c:647 [inline] madvise_vma_behavior+0x2951/0x43c0 mm/madvise.c:1366 madvise_walk_vmas+0x57a/0xaf0 mm/madvise.c:1721 madvise_do_behavior+0x386/0x540 mm/madvise.c:1937 do_madvise+0x1fa/0x2e0 mm/madvise.c:2030 __do_sys_madvise mm/madvise.c:2039 [inline] __se_sys_madvise mm/madvise.c:2037 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:2037 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2b3459c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2b35495028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f2b34815fa0 RCX: 00007f2b3459c799 RDX: 0000000000000015 RSI: 0000000000600000 RDI: 0000200000000000 RBP: 00007f2b34632c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2b34816038 R14: 00007f2b34815fa0 R15: 00007ffcfbbae8f8 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com.