From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 E42F22857EA for ; Tue, 26 May 2026 05:49:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779774571; cv=none; b=BXKwmDtEtKn6GyLeBxKTFVNqUV35VFxSKzU+WFgP5hfhh0sFap0b2EzvUTirybi60jCnoXspkJXMPGwuU4LVY09Ey8tV1gtf1yZobGe+ogoWmRdxdDv5jzRVZpbvdpYTccvXlf48T4mxJvaqgAXhbNPPF6J/bhK8BgHeHM9FeGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779774571; c=relaxed/simple; bh=x9Yj7aTg1GQQSh+x9b/Ecjqf4DMAz/ZV+Y+LafBK3r4=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; 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006d021491bc7-69d91536352mr7102173eaf.41.1779774568882; Mon, 25 May 2026 22:49:28 -0700 (PDT) Date: Mon, 25 May 2026 22:49:28 -0700 In-Reply-To: <20260525165528.184397-1-osalvador@suse.de> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a153468.050a0220.7dd1.0004.GAE@google.com> Subject: [syzbot ci] Re: Implement a new generic pagewalk API From: syzbot ci To: akpm@linux-foundation.org, david@kernel.org, david@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, mhocko@suse.com, muchun.song@linux.dev, osalvador@suse.de, vbabka@kernel.org Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v3] Implement a new generic pagewalk API https://lore.kernel.org/all/20260525165528.184397-1-osalvador@suse.de * [RFC PATCH v3 1/8] mm: Add softleaf_from_pud * [RFC PATCH v3 2/8] mm: Add {pmd,pud}_huge_lock helper * [RFC PATCH v3 3/8] mm: Implement folio_pmd_batch * [RFC PATCH v3 4/8] mm: Implement pt_range_walk * [RFC PATCH v3 5/8] mm: Make /proc/pid/smaps use the new generic pagewalk API * [RFC PATCH v3 6/8] mm: Make /proc/pid/numa_maps use the new generic pagewalk API * [RFC PATCH v3 7/8] mm: Make /proc/pid/pagemap use the new generic pagewalk API * [RFC PATCH v3 8/8] mm: Make /proc/pid/clear_refs use the new generic pagewalk API and found the following issue: general protection fault in clear_refs_write Full report is available here: https://ci.syzbot.org/series/0beab2d0-9d88-4288-ac81-b294e51c057d *** general protection fault in clear_refs_write tree: mm-new URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git base: 5200f5f493f79f14bbdc349e402a40dfb32f23c8 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/8f20e88b-808c-4c60-9b8e-0af4c9fce5ff/config syz repro: https://ci.syzbot.org/findings/634b1f0a-cf64-4607-928a-ef3ad40f765c/syz_repro Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 5863 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 RIP: 0010:clear_soft_dirty_pmd fs/proc/task_mmu.c:1545 [inline] RIP: 0010:clear_refs_pmd_range fs/proc/task_mmu.c:1581 [inline] RIP: 0010:clear_refs_write+0xaa7/0x1590 fs/proc/task_mmu.c:1721 Code: 44 24 10 4c 8b bc 24 20 02 00 00 83 7c 24 28 04 0f 85 aa 05 00 00 48 8b 9c 24 08 02 00 00 48 89 d8 48 c1 e8 03 48 89 44 24 58 <42> 80 3c 20 00 74 08 48 89 df e8 fa 2c c6 ff 4c 8b 23 4c 89 e6 48 RSP: 0018:ffffc900037bf960 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000005 RDX: ffffffff826b21ce RSI: ffffffff8eb17b50 RDI: 0000000000000001 RBP: ffffc900037bfc10 R08: ffff8881047c0000 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000000 R12: dffffc0000000000 R13: fffff520006f7f40 R14: ffff8881141c8308 R15: ffff8881141c8300 FS: 00007ff8ffc1d6c0(0000) GS:ffff8882a928a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33e63fff CR3: 000000010476e000 CR4: 00000000000006f0 Call Trace: do_loop_readv_writev fs/read_write.c:852 [inline] vfs_writev+0x4bd/0x990 fs/read_write.c:1061 do_writev+0x154/0x2e0 fs/read_write.c:1105 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8fed9ce59 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:00007ff8ffc1d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007ff8ff015fa0 RCX: 00007ff8fed9ce59 RDX: 0000000000000001 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007ff8fee32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff8ff016038 R14: 00007ff8ff015fa0 R15: 00007fffd02796e8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:clear_soft_dirty_pmd fs/proc/task_mmu.c:1545 [inline] RIP: 0010:clear_refs_pmd_range fs/proc/task_mmu.c:1581 [inline] RIP: 0010:clear_refs_write+0xaa7/0x1590 fs/proc/task_mmu.c:1721 Code: 44 24 10 4c 8b bc 24 20 02 00 00 83 7c 24 28 04 0f 85 aa 05 00 00 48 8b 9c 24 08 02 00 00 48 89 d8 48 c1 e8 03 48 89 44 24 58 <42> 80 3c 20 00 74 08 48 89 df e8 fa 2c c6 ff 4c 8b 23 4c 89 e6 48 RSP: 0018:ffffc900037bf960 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000005 RDX: ffffffff826b21ce RSI: ffffffff8eb17b50 RDI: 0000000000000001 RBP: ffffc900037bfc10 R08: ffff8881047c0000 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000000 R12: dffffc0000000000 R13: fffff520006f7f40 R14: ffff8881141c8308 R15: ffff8881141c8300 FS: 00007ff8ffc1d6c0(0000) GS:ffff8882a928a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34063fff CR3: 000000010476e000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: 44 24 10 rex.R and $0x10,%al 3: 4c 8b bc 24 20 02 00 mov 0x220(%rsp),%r15 a: 00 b: 83 7c 24 28 04 cmpl $0x4,0x28(%rsp) 10: 0f 85 aa 05 00 00 jne 0x5c0 16: 48 8b 9c 24 08 02 00 mov 0x208(%rsp),%rbx 1d: 00 1e: 48 89 d8 mov %rbx,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 48 89 44 24 58 mov %rax,0x58(%rsp) * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 fa 2c c6 ff call 0xffc62d33 39: 4c 8b 23 mov (%rbx),%r12 3c: 4c 89 e6 mov %r12,%rsi 3f: 48 rex.W *** 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.