Hello, syzbot found the following issue on: HEAD commit: 445d9f05fa14 Merge tag 'nfsd-6.13' of git://git.kernel.org.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=12733530580000 kernel config: https://syzkaller.appspot.com/x/.config?x=3c44a32edb32752c dashboard link: https://syzkaller.appspot.com/bug?extid=87b8e6ed25dbc41759f7 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11fd43c0580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15cf2f5f980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9fd8dd2a6550/disk-445d9f05.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/af034d90afcb/vmlinux-445d9f05.xz kernel image: https://storage.googleapis.com/syzbot-assets/07a713832258/bzImage-445d9f05.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+87b8e6ed25dbc41759f7@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: null-ptr-deref in fuse_copy_do+0x183/0x320 fs/fuse/dev.c:809 Write of size 5 at addr 0000000000000000 by task syz-executor159/5840 CPU: 0 UID: 0 PID: 5840 Comm: syz-executor159 Not tainted 6.12.0-syzkaller-09734-g445d9f05fa14 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 kasan_report+0xd9/0x110 mm/kasan/report.c:602 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 fuse_copy_do+0x183/0x320 fs/fuse/dev.c:809 fuse_copy_one fs/fuse/dev.c:1065 [inline] fuse_copy_args+0x1e6/0x770 fs/fuse/dev.c:1083 copy_out_args fs/fuse/dev.c:1966 [inline] fuse_dev_do_write+0x1cc1/0x3720 fs/fuse/dev.c:2052 fuse_dev_write+0x14f/0x1e0 fs/fuse/dev.c:2087 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa4c9df3c0f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 89 5e 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 dc 5e 02 00 48 RSP: 002b:00007fa4c9da71e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa4c9e7f3e8 RCX: 00007fa4c9df3c0f RDX: 0000000000000015 RSI: 0000000020000540 RDI: 0000000000000003 RBP: 00007fa4c9e7f3e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fa4c9e4c33c R13: 00007fa4c9e44027 R14: 00007fff3bcf2380 R15: 00007fa4c9e4a338 </TASK> ================================================================== --- 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
