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AHgh+Rq9bTXYNm/yVNCdhaSUrtGZ2GnMHkpXXSI719caETMdzK0retst2ubqKuII++uzomJqVYne98kNTM64O30=@vger.kernel.org X-Gm-Message-State: AOJu0YwEgnehoiMZYUsh1PRF6uWtD3r4Ww3eADhYGLKAxXWh4LzdmUzM iL8tYElWQhLTvmnxNaZOIrBw9grnnbd8JQbpV5v3QwnI2EMV9kOSKaLyJgsoj6QiGV+CdhDXPKx RsPNAmSIi/ibxxZVFO7AvakaWNh2YX3B5L00zzLYdgr0zj/pxpVFGwx8r37M= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1b14:b0:49b:e1e2:81b6 with SMTP id 5614622812f47-4a4d0508418mr8913489b6e.27.1784626716002; Tue, 21 Jul 2026 02:38:36 -0700 (PDT) Date: Tue, 21 Jul 2026 02:38:35 -0700 In-Reply-To: <20260720142913.846902-1-pfalcato@suse.de> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a5f3e1b.33ea6125.251e5.0001.GAE@google.com> Subject: [syzbot ci] Re: mm/khugepaged: collapse_file() cleanups From: syzbot ci To: akpm@linux-foundation.org, baohua@kernel.org, baolin.wang@linux.alibaba.com, david@kernel.org, dev.jain@arm.com, lance.yang@linux.dev, liam@infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, npache@redhat.com, pfalcato@suse.de, ryan.roberts@arm.com, usama.arif@linux.dev, ziy@nvidia.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v1] mm/khugepaged: collapse_file() cleanups https://lore.kernel.org/all/20260720142913.846902-1-pfalcato@suse.de * [PATCH 1/8] mm/khugepaged: separate out windy folio logic from collapse_file * [PATCH 2/8] mm/khugepaged: factor out page cache folio reading * [PATCH 3/8] mm/khugepaged: factor out and simplify dirty/writeback handling * [PATCH 4/8] mm/khugepaged: simplify prepare folio locking and exit paths * [PATCH 5/8] mm/khugepaged: add kerneldoc to prepare_collapse_file_folio() * [PATCH 6/8] mm/khugepaged: hoist isolation into collapse_isolate_folio() * [PATCH 7/8] mm/khugepaged: hoist more code into collapse_isolate_folio() * [PATCH 8/8] mm/khugepaged: fix and flesh out try_to_unmap_flush() comment and found the following issue: WARNING: bad unlock balance in collapse_scan_file Full report is available here: https://ci.syzbot.org/series/cc30d9d4-857a-45de-a8e8-b99f9346d0da *** WARNING: bad unlock balance in collapse_scan_file tree: mm-new URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git base: c872b70f5d6c742ad34b8e838c92af81c8920b3e arch: amd64 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 config: https://ci.syzbot.org/builds/e6e237b7-5a64-4732-bb37-4e62c3103d4a/config syz repro: https://ci.syzbot.org/findings/51ee94c3-7fe6-47f6-81ed-a53cf51bb3f9/syz_repro ===================================== WARNING: bad unlock balance detected! syzkaller #0 Not tainted ------------------------------------- syz.0.17/5868 is trying to release lock (&xa->xa_lock) at: [] spin_unlock_irq include/linux/spinlock.h:402 [inline] [] prepare_collapse_file_folio mm/khugepaged.c:2331 [inline] [] collapse_file mm/khugepaged.c:2539 [inline] [] collapse_scan_file+0x2cbf/0x4dc0 mm/khugepaged.c:2849 but there are no more locks to release! other info that might help us debug this: no locks held by syz.0.17/5868. stack backtrace: CPU: 0 UID: 0 PID: 5868 Comm: syz.0.17 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_unlock_imbalance_bug+0xdc/0xf0 kernel/locking/lockdep.c:5299 __lock_release kernel/locking/lockdep.c:5528 [inline] lock_release+0x1fb/0x3c0 kernel/locking/lockdep.c:5912 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:185 [inline] _raw_spin_unlock_irq+0x16/0x50 kernel/locking/spinlock.c:206 spin_unlock_irq include/linux/spinlock.h:402 [inline] prepare_collapse_file_folio mm/khugepaged.c:2331 [inline] collapse_file mm/khugepaged.c:2539 [inline] collapse_scan_file+0x2cbf/0x4dc0 mm/khugepaged.c:2849 collapse_single_pmd+0x2b1/0x3da0 mm/khugepaged.c:2884 madvise_collapse+0x2cf/0x790 mm/khugepaged.c:3310 madvise_vma_behavior+0x115f/0x4170 mm/madvise.c:1363 madvise_walk_vmas+0x576/0xb00 mm/madvise.c:1712 madvise_do_behavior+0x385/0x540 mm/madvise.c:1907 do_madvise+0x327/0x3a0 mm/madvise.c:2005 __do_sys_madvise mm/madvise.c:2014 [inline] __se_sys_madvise mm/madvise.c:2012 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:2012 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb60079de99 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:00007fb6015c0028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007fb600a25fa0 RCX: 00007fb60079de99 RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000200000000000 RBP: 00007fb600833eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb600a26038 R14: 00007fb600a25fa0 R15: 00007ffc7db2f618 *** 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. To test a patch for this bug, please reply with `#syz test` (should be on a separate line). The patch should be attached to the email. Note: arguments like custom git repos and branches are not supported.