syzbot has found a reproducer for the following issue on: HEAD commit: 865fdb08197e Merge tag 'input-for-v6.4-rc0' of git://git.k.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=133efa8c280000 kernel config: https://syzkaller.appspot.com/x/.config?x=d1c8518c09009bad dashboard link: https://syzkaller.appspot.com/bug?extid=48011b86c8ea329af1b9 compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=137594c4280000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10cfd602280000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/c667de87f318/disk-865fdb08.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f5d4a94eb2fa/vmlinux-865fdb08.xz kernel image: https://storage.googleapis.com/syzbot-assets/2b0950e1688b/bzImage-865fdb08.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/21df08f169b8/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+48011b86c8ea329af1b9@xxxxxxxxxxxxxxxxxxxxxxxxx Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb7ca8738 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f56c0f9bd69 RDX: 000000000208e24b RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00007ffdb7ca8740 R08: 0000000000000001 R09: 00007f56c0f50032 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] BUG: KASAN: null-ptr-deref in page_ref_count include/linux/page_ref.h:67 [inline] BUG: KASAN: null-ptr-deref in put_page_testzero include/linux/mm.h:996 [inline] BUG: KASAN: null-ptr-deref in folio_put_testzero include/linux/mm.h:1002 [inline] BUG: KASAN: null-ptr-deref in folio_put include/linux/mm.h:1429 [inline] BUG: KASAN: null-ptr-deref in filemap_fault+0x121e/0x1810 mm/filemap.c:3382 Read of size 4 at addr 0000000000000028 by task syz-executor223/4990 CPU: 0 PID: 4990 Comm: syz-executor223 Not tainted 6.3.0-syzkaller-12423-g865fdb08197e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_report+0xe6/0x540 mm/kasan/report.c:465 kasan_report+0x176/0x1b0 mm/kasan/report.c:572 kasan_check_range+0x283/0x290 mm/kasan/generic.c:187 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] page_ref_count include/linux/page_ref.h:67 [inline] put_page_testzero include/linux/mm.h:996 [inline] folio_put_testzero include/linux/mm.h:1002 [inline] folio_put include/linux/mm.h:1429 [inline] filemap_fault+0x121e/0x1810 mm/filemap.c:3382 __do_fault+0x136/0x500 mm/memory.c:4176 do_read_fault mm/memory.c:4530 [inline] do_fault mm/memory.c:4659 [inline] do_pte_missing mm/memory.c:3647 [inline] handle_pte_fault mm/memory.c:4947 [inline] __handle_mm_fault mm/memory.c:5089 [inline] handle_mm_fault+0x41a8/0x5860 mm/memory.c:5243 do_user_addr_fault arch/x86/mm/fault.c:1440 [inline] handle_page_fault arch/x86/mm/fault.c:1534 [inline] exc_page_fault+0x7d2/0x910 arch/x86/mm/fault.c:1590 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:fault_in_readable+0x1db/0x350 mm/gup.c:1863 Code: bf ff 48 89 d8 4c 8d ab ff 0f 00 00 4d 01 e5 49 81 e5 00 f0 ff ff 49 39 c5 72 70 e8 6f b5 bf ff 4c 39 eb 74 73 4c 89 64 24 10 <44> 8a 23 43 0f b6 04 3e 84 c0 75 18 44 88 64 24 40 48 81 c3 00 10 RSP: 0018:ffffc90003aaf9c0 EFLAGS: 00050287 RAX: ffffffff81cbda01 RBX: 0000000020000000 RCX: ffff888027d3bb80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003aafa78 R08: ffffffff81cbd9a3 R09: ffffffff84310069 R10: 0000000000000002 R11: ffff888027d3bb80 R12: 0000000000001000 R13: 0000000020001000 R14: 1ffff92000755f40 R15: dffffc0000000000 fault_in_iov_iter_readable+0xdf/0x280 lib/iov_iter.c:362 generic_perform_write+0x20b/0x5e0 mm/filemap.c:3913 __generic_file_write_iter+0x17a/0x400 mm/filemap.c:4051 udf_file_write_iter+0x2fc/0x660 fs/udf/file.c:115 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ec/0xc10 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f56c0f9bd69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb7ca8738 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f56c0f9bd69 RDX: 000000000208e24b RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00007ffdb7ca8740 R08: 0000000000000001 R09: 00007f56c0f50032 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ================================================================== ---------------- Code disassembly (best guess): 0: 28 00 sub %al,(%rax) 2: 00 00 add %al,(%rax) 4: 75 05 jne 0xb 6: 48 83 c4 28 add $0x28,%rsp a: c3 retq b: e8 51 14 00 00 callq 0x1461 10: 90 nop 11: 48 89 f8 mov %rdi,%rax 14: 48 89 f7 mov %rsi,%rdi 17: 48 89 d6 mov %rdx,%rsi 1a: 48 89 ca mov %rcx,%rdx 1d: 4d 89 c2 mov %r8,%r10 20: 4d 89 c8 mov %r9,%r8 23: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 28: 0f 05 syscall * 2a: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 30: 73 01 jae 0x33 32: c3 retq 33: 48 c7 c1 c0 ff ff ff mov $0xffffffffffffffc0,%rcx 3a: f7 d8 neg %eax 3c: 64 89 01 mov %eax,%fs:(%rcx) 3f: 48 rex.W --- 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.
