From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f79.google.com (mail-ot1-f79.google.com [209.85.210.79]) (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 F2A0A231A3B for ; Mon, 10 Aug 2026 00:34:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786322071; cv=none; b=DLy2hU33yFu17D9nVb3LI81S6WvRmsLgp4HZaOSk6RrzFaWZLM5eeG5jzlOjmSat64MYN46pPrVHDjgO3l9K/nnb29SrtrhmLUYjwthJ8USwzV0GxdvCx0VcZESVk54u4fY0OmkAU46FM2k+Ys5fTdVdf0grvr1OunT/uFZP3Y0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786322071; c=relaxed/simple; bh=jkLnIQnsujoKnXtattySxuSWk5uApWntLBaWW4dTS/Y=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=T44M9oeUWdYvE9WV2Xy2j4PNyhBy7jrJFxUHL1aKDcSuD13jRX5RgfDkxd7O9/G4UVXO7tLKLBRY9kfcL4FAaK8uR0RVSjL3i66NpLa1s3CuEv/6s+kYvF8AEa/NW2l00AnXTx2iUb2NSXcVWVubQtMaXbUM9EfNhhXIAOHm2kA= 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=209.85.210.79 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-ot1-f79.google.com with SMTP id 46e09a7af769-7ebfcb4c999so2217082a34.1 for ; Sun, 09 Aug 2026 17:34:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786322069; x=1786926869; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=E4stc6q/YjnR6zOACY45yGoHWgorHHlXz7m6/y9/btE=; b=EEMWmNBpzIByLKSrjCVJ/k94CNnz9c6tu/VF0Eclse108AV22tWPS3+4fND6wXCO0g Pk9dL79vwoa1yJ1Dl9MMXclRs4W5anIB4ZB8fZp+7iGMBjr3PATjwPMrU5yodjOrv+/G HxiS1ULOkW72B8BCUiuJG2Qu2VDxqJ9VUMcIkO73cxgyIc4La1FDSHWkfmvHFIwYwRvn gJqSzTHgPBF9ji/aKqYxikefN3RMwXQlbGMx89bypgblP1etOiE/V2lolFHdDuz1845g 1xnHehQ3NS0iyOFExmqrE/kmpcAgmJB52gFR2v9a3P52Ui37GMpxMjgt4MM4dC+lWzgQ QDnA== X-Forwarded-Encrypted: i=1; AHgh+RrLfkKDnQB0+rpjLhBg+U6vloQYir04qdEB7setIqLzQdrNic059kpEOpj07I2JG4r7uScnRiriqekU/4c=@vger.kernel.org X-Gm-Message-State: AOJu0YzZkhHJGvqkCmgBsRRjNW6GKZLrm8sW5O1IO+eQM7bdbyyouRF9 Wo8hBuNyE0Op9FruI/QKf9RS3M26pRdQncOuRkf/iU8y/asKEcncx110FgtRf5MAwAxUba2iOYa 4b7H/kxyV6w6gf7GCqqDZo3cWgBPyETUvgbmGNouoH/fno6Gx4e1ZLzMtUBM= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a4a:ee87:0:b0:6aa:d8d9:a4bb with SMTP id 006d021491bc7-6ae970f14f6mr20924502eaf.36.1786322068894; Sun, 09 Aug 2026 17:34:28 -0700 (PDT) Date: Sun, 09 Aug 2026 17:34:28 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a791c94.01d0871a.3a0d52.009b.GAE@google.com> Subject: [syzbot] [mtd?] divide error in block2mtd_setup2 From: syzbot To: joern@lazybastard.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com, richard@nod.at, syzkaller-bugs@googlegroups.com, vigneshr@ti.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=149f2cc6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c05be6c9b0d36cb9 dashboard link: https://syzkaller.appspot.com/bug?extid=b320a4d5f65a61dbbf89 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-848acc8f.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2425c07b5d46/vmlinux-848acc8f.xz kernel image: https://storage.googleapis.com/syzbot-assets/cf278dd14da3/bzImage-848acc8f.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b320a4d5f65a61dbbf89@syzkaller.appspotmail.com Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:add_device drivers/mtd/devices/block2mtd.c:296 [inline] RIP: 0010:block2mtd_setup2+0x592/0xda0 drivers/mtd/devices/block2mtd.c:459 Code: 48 8b 74 24 30 48 63 ce 48 89 d8 48 09 c8 48 c1 e8 20 4c 8b 64 24 10 74 0d 48 89 d8 48 99 48 f7 f9 49 89 d5 eb 09 89 d8 31 d2 f6 41 89 d5 31 ff 4c 89 ee e8 1f da 39 fb 4d 85 ed 0f 85 90 04 RSP: 0018:ffffc9000f26f9a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001f00000 RBP: ffffc9000f26fb98 R08: ffff8880353962ef R09: 1ffff11006a72c5d R10: dffffc0000000000 R11: ffffed1006a72c5e R12: 0000000000000000 R13: ffff88801d02d0b4 R14: ffff8880122be000 R15: ffff8880122be000 FS: 00007fa7d8c5d6c0(0000) GS:ffff88808c540000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa7d801bb30 CR3: 000000003fb3c000 CR4: 0000000000352ef0 Call Trace: block2mtd_setup+0x27/0xe0 drivers/mtd/devices/block2mtd.c:476 param_attr_store+0x214/0x310 kernel/params.c:589 module_attr_store+0x65/0x90 kernel/params.c:904 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 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: 0033:0x7fa7d7d9e019 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:00007fa7d8c5cfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa7d8025fa0 RCX: 00007fa7d7d9e019 RDX: 000000000000000c RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fa7d7e3500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa7d8026038 R14: 00007fa7d8025fa0 R15: 00007ffe5587a628 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:add_device drivers/mtd/devices/block2mtd.c:296 [inline] RIP: 0010:block2mtd_setup2+0x592/0xda0 drivers/mtd/devices/block2mtd.c:459 Code: 48 8b 74 24 30 48 63 ce 48 89 d8 48 09 c8 48 c1 e8 20 4c 8b 64 24 10 74 0d 48 89 d8 48 99 48 f7 f9 49 89 d5 eb 09 89 d8 31 d2 f6 41 89 d5 31 ff 4c 89 ee e8 1f da 39 fb 4d 85 ed 0f 85 90 04 RSP: 0018:ffffc9000f26f9a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001f00000 RBP: ffffc9000f26fb98 R08: ffff8880353962ef R09: 1ffff11006a72c5d R10: dffffc0000000000 R11: ffffed1006a72c5e R12: 0000000000000000 R13: ffff88801d02d0b4 R14: ffff8880122be000 R15: ffff8880122be000 FS: 00007fa7d8c5d6c0(0000) GS:ffff88808c540000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffee237bf52 CR3: 000000003fb3c000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: 48 8b 74 24 30 mov 0x30(%rsp),%rsi 5: 48 63 ce movslq %esi,%rcx 8: 48 89 d8 mov %rbx,%rax b: 48 09 c8 or %rcx,%rax e: 48 c1 e8 20 shr $0x20,%rax 12: 4c 8b 64 24 10 mov 0x10(%rsp),%r12 17: 74 0d je 0x26 19: 48 89 d8 mov %rbx,%rax 1c: 48 99 cqto 1e: 48 f7 f9 idiv %rcx 21: 49 89 d5 mov %rdx,%r13 24: eb 09 jmp 0x2f 26: 89 d8 mov %ebx,%eax 28: 31 d2 xor %edx,%edx * 2a: f7 f6 div %esi <-- trapping instruction 2c: 41 89 d5 mov %edx,%r13d 2f: 31 ff xor %edi,%edi 31: 4c 89 ee mov %r13,%rsi 34: e8 1f da 39 fb call 0xfb39da58 39: 4d 85 ed test %r13,%r13 3c: 0f .byte 0xf 3d: 85 .byte 0x85 3e: 90 nop 3f: 04 .byte 0x4 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup