(cc bpf@) On Fri, 12 Apr 2024 19:27:25 -0700 syzbot <syzbot+79102ed905e5b2dc0fc3@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: fec50db7033e Linux 6.9-rc3 > git tree: upstream > console+strace: https://syzkaller.appspot.com/x/log.txt?x=16509ba1180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=13e7da432565d94c > dashboard link: https://syzkaller.appspot.com/bug?extid=79102ed905e5b2dc0fc3 > 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=10a4af9d180000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12980f9d180000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/901017b36ccc/disk-fec50db7.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/16bfcf5618d3/vmlinux-fec50db7.xz > kernel image: https://storage.googleapis.com/syzbot-assets/dc9c5a1e7d02/bzImage-fec50db7.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+79102ed905e5b2dc0fc3@xxxxxxxxxxxxxxxxxxxxxxxxx > > ===================================================== > BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] > BUG: KMSAN: kernel-infoleak in __copy_to_user_inatomic include/linux/uaccess.h:125 [inline] > BUG: KMSAN: kernel-infoleak in copy_to_user_nofault+0x129/0x1f0 mm/maccess.c:149 > instrument_copy_to_user include/linux/instrumented.h:114 [inline] > __copy_to_user_inatomic include/linux/uaccess.h:125 [inline] > copy_to_user_nofault+0x129/0x1f0 mm/maccess.c:149 > ____bpf_probe_write_user kernel/trace/bpf_trace.c:349 [inline] > bpf_probe_write_user+0x104/0x180 kernel/trace/bpf_trace.c:327 > ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 > __bpf_prog_run64+0xb5/0xe0 kernel/bpf/core.c:2236 > 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_run2+0x116/0x300 kernel/trace/bpf_trace.c:2420 > __bpf_trace_kfree+0x29/0x40 include/trace/events/kmem.h:94 > trace_kfree include/trace/events/kmem.h:94 [inline] > kfree+0x6a5/0xa30 mm/slub.c:4377 > vfs_writev+0x12bf/0x1450 fs/read_write.c:978 > do_writev+0x251/0x5c0 fs/read_write.c:1018 > __do_sys_writev fs/read_write.c:1091 [inline] > __se_sys_writev fs/read_write.c:1088 [inline] > __x64_sys_writev+0x98/0xe0 fs/read_write.c:1088 > do_syscall_64+0xd5/0x1f0 > entry_SYSCALL_64_after_hwframe+0x72/0x7a > > Local variable stack created at: > __bpf_prog_run64+0x45/0xe0 kernel/bpf/core.c:2236 > 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_run2+0x116/0x300 kernel/trace/bpf_trace.c:2420 > > Bytes 0-7 of 8 are uninitialized > Memory access of size 8 starts at ffff888121ec7ae8 > Data copied to user address 00000000ffffffff > > CPU: 1 PID: 4779 Comm: dhcpcd Not tainted 6.9.0-rc3-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > ===================================================== > > > --- > 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 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
