================================================================== 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-executor.2/23763 CPU: 0 PID: 23763 Comm: syz-executor.2 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: __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:ffffc900060d78e0 EFLAGS: 00050287 RAX: ffffffff81cbda01 RBX: 0000000020000000 RCX: 0000000000040000 RDX: ffffc90006ae1000 RSI: 000000000000005b RDI: 000000000000005c RBP: ffffc900060d7998 R08: ffffffff81cbd9a3 R09: ffffffff84310069 R10: 0000000000000002 R11: ffff88807c8ebb80 R12: 0000000000001000 R13: 0000000020001000 R14: 1ffff92000c1af24 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 blkdev_write_iter+0x429/0x750 block/fops.c:549 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: 0033:0x7fcbe6e8c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcbe7cce168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fcbe6fabf80 RCX: 00007fcbe6e8c169 RDX: 000000000208e24b RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00007fcbe7cce1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdc73f64bf R14: 00007fcbe7cce300 R15: 0000000000022000 ================================================================== ---------------- Code disassembly (best guess): 0: bf ff 48 89 d8 mov $0xd88948ff,%edi 5: 4c 8d ab ff 0f 00 00 lea 0xfff(%rbx),%r13 c: 4d 01 e5 add %r12,%r13 f: 49 81 e5 00 f0 ff ff and $0xfffffffffffff000,%r13 16: 49 39 c5 cmp %rax,%r13 19: 72 70 jb 0x8b 1b: e8 6f b5 bf ff callq 0xffbfb58f 20: 4c 39 eb cmp %r13,%rbx 23: 74 73 je 0x98 25: 4c 89 64 24 10 mov %r12,0x10(%rsp) * 2a: 44 8a 23 mov (%rbx),%r12b <-- trapping instruction 2d: 43 0f b6 04 3e movzbl (%r14,%r15,1),%eax 32: 84 c0 test %al,%al 34: 75 18 jne 0x4e 36: 44 88 64 24 40 mov %r12b,0x40(%rsp) 3b: 48 rex.W 3c: 81 .byte 0x81 3d: c3 retq 3e: 00 10 add %dl,(%rax)