Hello, syzbot found the following issue on: HEAD commit: 39cd87c4eb2b Linux 6.9-rc2 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=13891cc5180000 kernel config: https://syzkaller.appspot.com/x/.config?x=5112b3f484393436 dashboard link: https://syzkaller.appspot.com/bug?extid=aca389a8a7da35c070ce compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11629a19180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169e86e5180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/dba7eac545d2/disk-39cd87c4.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ddf1c8e07b17/vmlinux-39cd87c4.xz kernel image: https://storage.googleapis.com/syzbot-assets/808527761eab/bzImage-39cd87c4.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+aca389a8a7da35c070ce@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in percpu_array_map_lookup_percpu_elem+0x1cb/0x200 kernel/bpf/arraymap.c:257 percpu_array_map_lookup_percpu_elem+0x1cb/0x200 kernel/bpf/arraymap.c:257 ____bpf_map_lookup_percpu_elem kernel/bpf/helpers.c:133 [inline] bpf_map_lookup_percpu_elem+0x67/0x90 kernel/bpf/helpers.c:130 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run288+0xb5/0xe0 kernel/bpf/core.c:2237 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run8+0x1bd/0x3a0 kernel/trace/bpf_trace.c:2426 __bpf_trace_jbd2_handle_stats+0x51/0x70 include/trace/events/jbd2.h:210 trace_jbd2_handle_stats include/trace/events/jbd2.h:210 [inline] jbd2_journal_stop+0x1157/0x12c0 fs/jbd2/transaction.c:1869 __ext4_journal_stop+0x115/0x310 fs/ext4/ext4_jbd2.c:134 ext4_do_writepages+0x1c3c/0x62e0 fs/ext4/inode.c:2692 ext4_writepages+0x312/0x830 fs/ext4/inode.c:2768 do_writepages+0x427/0xc30 mm/page-writeback.c:2612 __writeback_single_inode+0x10d/0x12c0 fs/fs-writeback.c:1650 writeback_sb_inodes+0xb48/0x1be0 fs/fs-writeback.c:1941 __writeback_inodes_wb+0x14c/0x440 fs/fs-writeback.c:2012 wb_writeback+0x4da/0xdf0 fs/fs-writeback.c:2119 wb_check_old_data_flush fs/fs-writeback.c:2223 [inline] wb_do_writeback fs/fs-writeback.c:2276 [inline] wb_workfn+0x110c/0x1940 fs/fs-writeback.c:2304 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa81/0x1bd0 kernel/workqueue.c:3335 worker_thread+0xea5/0x1560 kernel/workqueue.c:3416 kthread+0x3e2/0x540 kernel/kthread.c:388 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Local variable stack created at: __bpf_prog_run288+0x45/0xe0 kernel/bpf/core.c:2237 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run8+0x1bd/0x3a0 kernel/trace/bpf_trace.c:2426 CPU: 1 PID: 1070 Comm: kworker/u8:7 Not tainted 6.9.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: writeback wb_workfn (flush-8:0) ===================================================== --- 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 syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. 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
