From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi2-f1.google.com (mail-oi2-f1.google.com [74.125.231.193]) (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 481BB2E2840 for ; Sun, 23 Aug 2026 13:33:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.193 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787492019; cv=none; b=GJiTXOmJeKI7EQ8buBhX25PPDCZVXG6BXJAticRvdT6TZOxbfRrQqSVYQaTX/NKDLyhV35H0sJOL+XmVr2SZ0x0tpG8kFohgzv0/iMVwtqPj3/tuq2LCa7rLaa2AkrRH/mjSNws0f70W46M5P+ecbizTExX3/ypahqq//zYwVBs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787492019; c=relaxed/simple; bh=vuDsZ58m7adwJlb7O8pPJtCDIIe1SXmOdSl2YM5c37M=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=arj++efA5U3YZuBDpFMt/v03E/fQBLPerRObJkx7Ig+IM9p1WAdf6x8+PddW0JKCfHbf+uKbFcn5NZcyzM+0S6S3IKFpY3zG9IuFdQ0X/yyIgILkznQAI1p4QAYK0xvSj7sN7T4EvmvRp0c1MUmEWJM9xGnL/8QNUy7KisA/vVU= 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=74.125.231.193 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-oi2-f1.google.com with SMTP id 5614622812f47-495f936d5ecso919883b6e.0 for ; Sun, 23 Aug 2026 06:33:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787492017; x=1788096817; 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=uMnRxvlSXRGYGo8v3JEBUuAG5Qt2o3NIfRPMNhU2QKk=; b=WHrv9X0zctv3B9SJ2BveU2qAJp/hUqyyFejXMDnURqLwyReBGXr8LkpiymOTyDnMWV YHGCGkuwP4cS5kj51O4au5QczmSiwuPoOBG3VAmaJ/sS/wgRFTiOYk/ong3BVEhnMFGO g9KRXWvDhyWxf3B+etnO6LUOlpefQGoCI2dPuhHkuQID8W729piWZRU7bjASDaFl9f6i uJzZImXR266L81IBTZIEogI8eXsbZmt06skVz20eow1YXC1XUzKu3l7nM0UnkI6dd6dG z2+GuuQJ0GOAAJ76zAepCFmOqy6CZYLoI+ze7h61zUqwiQwEqpjElTi6TNE/28GHNbYF HdOA== X-Forwarded-Encrypted: i=1; AHgh+RpDiLeqsbQxktBn/D9hEQFAwtv6WDSbSwhZlKiikdzTmVhtVLCUl+n7GwEMoAIHYAnbiQ7s1PCm0wQg2w==@vger.kernel.org X-Gm-Message-State: AFuF++lbWtbwDlAR7nPpReQXG+svdrP5hcYOCd2d7yaKPSg1DzAB4sPt G1rndb/nrqLba3gtjwzLLVTieSHh5CNSBcIfuDp0J85f16ttWxZYIbkZarFOcot8OaBXv4Re5Po sVgBJ4w0+Y6sN4ZE8LNEfxKCzl5u6NwNrP0qJoi4+SsoNyjejBws8HBdNm9w= Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1a07:b0:489:93ff:9ea0 with SMTP id 5614622812f47-4b3099d26e6mr12179248b6e.2.1787492017181; Sun, 23 Aug 2026 06:33:37 -0700 (PDT) Date: Sun, 23 Aug 2026 06:33:37 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a8af6b1.ae6ddae5.3da009.0067.GAE@google.com> Subject: [syzbot] [block?] [trace?] KASAN: slab-out-of-bounds Read in seq_buf_putmem From: syzbot To: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, rostedt@goodmis.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: a4ff2be345d0 Merge tag 'v7.3-p1' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17cff815580000 kernel config: https://syzkaller.appspot.com/x/.config?x=795e664af74a515 dashboard link: https://syzkaller.appspot.com/bug?extid=f179b16e13624138b0f1 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: https://storage.googleapis.com/syzbot-assets/c0b102f1cc94/disk-a4ff2be3.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f56c62ae89f0/vmlinux-a4ff2be3.xz kernel image: https://storage.googleapis.com/syzbot-assets/917b1eb284e1/bzImage-a4ff2be3.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f179b16e13624138b0f1@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-out-of-bounds in seq_buf_putmem+0x124/0x180 lib/seq_buf.c:241 Read of size 1352 at addr ffff8880295bdb98 by task syz.2.2551/19243 CPU: 1 UID: 0 PID: 19243 Comm: syz.2.2551 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 seq_buf_putmem+0x124/0x180 lib/seq_buf.c:241 blk_trace_synthesize_old_trace kernel/trace/blktrace.c:1780 [inline] blk_trace_event_print_binary+0x130/0x1b0 kernel/trace/blktrace.c:1788 tracing_read_pipe+0x568/0xb50 kernel/trace/trace.c:5444 vfs_read+0x213/0xa80 fs/read_write.c:572 ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f32fcb9e0d9 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:00007f32fd9ac028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f32fce25fa0 RCX: 00007f32fcb9e0d9 RDX: 00000000fffffe23 RSI: 0000200000001500 RDI: 0000000000000003 RBP: 00007f32fcc35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f32fce26038 R14: 00007f32fce25fa0 R15: 00007ffe116411a8 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880295bd000 pfn:0x295bd flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff8880295bd000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x44dc0(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 16263, tgid 16262 (syz.4.1733), ts 1361028187121, free_ts 1361025032368 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fe/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 __alloc_pages_noprof+0x10/0x100 mm/page_alloc.c:5338 __alloc_pages_node_noprof include/linux/gfp.h:291 [inline] alloc_pages_node_noprof include/linux/gfp.h:318 [inline] alloc_cpu_data kernel/trace/ring_buffer.c:438 [inline] __rb_allocate_pages+0xe97/0x17f0 kernel/trace/ring_buffer.c:2496 ring_buffer_resize+0x51d/0x1670 kernel/trace/ring_buffer.c:3327 __tracing_resize_ring_buffer+0x9c/0x310 kernel/trace/trace.c:4738 tracing_set_tracer+0x83/0x790 kernel/trace/trace.c:5014 tracing_set_trace_write+0x147/0x210 kernel/trace/trace.c:5131 vfs_write+0x296/0xba0 fs/read_write.c:685 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 23 tgid 23 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc22/0xd20 mm/page_alloc.c:2950 __tlb_remove_table_free mm/mmu_gather.c:228 [inline] tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:291 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x794/0x10b0 kernel/rcu/tree.c:2897 handle_softirqs+0x226/0x860 kernel/softirq.c:645 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1108 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff8880295bdf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880295be000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880295be080: 00 00 00 00 00 00 00 00 01 fc fc fc fc fc fc fc ^ ffff8880295be100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880295be180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- 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