On Mon, Sep 02, 2024 at 10:26:10AM +0200, Thomas Gleixner wrote: > On Thu, Aug 29 2024 at 09:53, syzbot wrote: > > Cc-: x86 folks. Just because something happens on x86 does not mean it's > an x86 problem > > Cc+: mm folks. It's entirely clear where this belongs to: > > > read-write to 0xffffffff88bb27ac of 4 bytes by task 3354 on cpu 0: > > pcpu_update_empty_pages mm/percpu.c:602 [inline] > > No? > Yeah.. We discussed this a month ago [1], I just haven't had time. I'll send out the fix for this tonight/tmrw morning. Thanks, Dennis [1] https://lore.kernel.org/lkml/ZqCo7H2gcA1dvIr4@xsang-OptiPlex-9020/ > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: d5d547aa7b51 Merge tag 'random-6.11-rc6-for-linus' of git:.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=164c067b980000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=6fafac02e339cc84 > > dashboard link: https://syzkaller.appspot.com/bug?extid=6d392a44667baa45bb5a > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/e636aa58c364/disk-d5d547aa.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/f5ecd0d96afa/vmlinux-d5d547aa.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/fe7d474f148f/bzImage-d5d547aa.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+6d392a44667baa45bb5a@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ================================================================== > > BUG: KCSAN: data-race in pcpu_alloc_noprof / pcpu_balance_workfn > > > > read-write to 0xffffffff88bb27ac of 4 bytes by task 3354 on cpu 0: > > pcpu_update_empty_pages mm/percpu.c:602 [inline] > > pcpu_chunk_populated mm/percpu.c:1531 [inline] > > pcpu_balance_populated mm/percpu.c:2062 [inline] > > pcpu_balance_workfn+0x94e/0xa60 mm/percpu.c:2212 > > process_one_work kernel/workqueue.c:3231 [inline] > > process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312 > > worker_thread+0x526/0x6e0 kernel/workqueue.c:3389 > > kthread+0x1d1/0x210 kernel/kthread.c:389 > > ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > read to 0xffffffff88bb27ac of 4 bytes by task 6821 on cpu 1: > > pcpu_alloc_noprof+0x9a7/0x10c0 mm/percpu.c:1894 > > bpf_map_alloc_percpu+0xad/0x210 kernel/bpf/syscall.c:466 > > prealloc_init+0x19f/0x470 kernel/bpf/hashtab.c:341 > > htab_map_alloc+0x630/0x8e0 kernel/bpf/hashtab.c:576 > > map_create+0x83c/0xb90 kernel/bpf/syscall.c:1333 > > __sys_bpf+0x667/0x7a0 kernel/bpf/syscall.c:5692 > > __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] > > __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] > > __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5815 > > x64_sys_call+0x2625/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:322 > > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > > do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 > > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > > > value changed: 0x00000001 -> 0x00000004 > > > > Reported by Kernel Concurrency Sanitizer on: > > CPU: 1 UID: 0 PID: 6821 Comm: syz.4.1651 Not tainted 6.11.0-rc5-syzkaller-00081-gd5d547aa7b51 #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 > > ================================================================== > > > > > > --- > > 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@xxxxxxxxxxxxxxxx. > > > > 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 >
