Messages in this thread | | | Date | Wed, 3 Apr 2024 10:55:41 -0700 | Subject | Re: [syzbot] [bpf?] KMSAN: uninit-value in percpu_array_map_lookup_percpu_elem | From | Martin KaFai Lau <> |
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On 4/2/24 10:22 AM, syzbot wrote: > 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@syzkaller.appspotmail.com > > ===================================================== > 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) > =====================================================
#syz dup: [syzbot] [bpf?] [net?] KMSAN: uninit-value in dev_map_lookup_elem
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