general protection fault, probably for non-canonical address 0xdffffc00000000b2: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000590-0x0000000000000597] CPU: 1 PID: 4242 Comm: syz-executor.4 Not tainted 5.14.0-rc6-next-20210819-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:latency_exceeded block/blk-wbt.c:237 [inline] RIP: 0010:wb_timer_fn+0x149/0x1750 block/blk-wbt.c:360 Code: 03 80 3c 02 00 0f 85 79 13 00 00 48 8b 9b c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 90 05 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 46 13 00 00 48 8b 9b 90 05 00 00 48 b8 00 00 00 RSP: 0018:ffffc90000dc0c98 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 00000000000000b2 RSI: ffffffff83d3ea3d RDI: 0000000000000590 RBP: ffff88801abedc00 R08: 0000000000000003 R09: ffff88801abedd83 R10: ffffffff83d3ea32 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000000 R14: ffff888146638380 R15: ffff88801abedcd0 FS: 00007f081c5ce700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9c13b19c20 CR3: 00000000889fd000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: call_timer_fn+0x1ab/0x6c0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x133/0x190 kernel/softirq.c:636 irq_exit_rcu+0x9/0x30 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:clear_page_erms+0x7/0x10 arch/x86/lib/clear_page_64.S:49 Code: 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d9 90 c3 0f 1f 80 00 00 00 00 b9 00 10 00 00 31 c0 aa c3 cc cc cc cc cc cc 41 57 41 56 41 55 41 54 55 53 48 89 fb RSP: 0018:ffffc9000530f2e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000f40 RDX: ffffea00024c48c0 RSI: ffff888000000000 RDI: ffff8880931230c0 RBP: ffffea00024c48c0 R08: 0000160000000000 R09: ffffea00024c4900 R10: fffff9400049891e R11: ffffffff81b28b78 R12: 0000000000000000 R13: 0000000001141cca R14: 0000000000000001 R15: 0000000000000000 clear_page arch/x86/include/asm/page_64.h:49 [inline] clear_highpage include/linux/highmem.h:218 [inline] kernel_init_free_pages mm/page_alloc.c:1278 [inline] kernel_init_free_pages mm/page_alloc.c:1263 [inline] post_alloc_hook+0x1c5/0x230 mm/page_alloc.c:2414 prep_new_page mm/page_alloc.c:2424 [inline] get_page_from_freelist+0xa76/0x2f90 mm/page_alloc.c:4151 __alloc_pages+0x1ba/0x510 mm/page_alloc.c:5373 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2188 folio_alloc+0x1c/0x70 mm/mempolicy.c:2198 filemap_alloc_folio mm/filemap.c:1030 [inline] __filemap_get_folio+0x5f2/0xe60 mm/filemap.c:1944 pagecache_get_page+0x30/0x1a0 mm/folio-compat.c:125 ext4_da_write_begin+0x35c/0x11a0 fs/ext4/inode.c:2984 generic_perform_write+0x209/0x510 mm/filemap.c:3755 ext4_buffered_write_iter+0x244/0x500 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x472/0x750 fs/read_write.c:740 do_iter_write+0x18b/0x710 fs/read_write.c:866 vfs_writev+0x1aa/0x630 fs/read_write.c:939 do_pwritev fs/read_write.c:1036 [inline] __do_sys_pwritev fs/read_write.c:1083 [inline] __se_sys_pwritev fs/read_write.c:1078 [inline] __x64_sys_pwritev+0x231/0x310 fs/read_write.c:1078 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f081c5ce188 EFLAGS: 00000246 ORIG_RAX: 0000000000000128 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000000000018 RSI: 00000000200006c0 RDI: 0000000000000005 RBP: 00000000004bfcc4 R08: 0000000000000004 R09: 0000000000000000 R10: 000000000400fa7f R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffd273b3e6f R14: 00007f081c5ce300 R15: 0000000000022000 Modules linked in: ---[ end trace e63a76d3872c5004 ]--- RIP: 0010:latency_exceeded block/blk-wbt.c:237 [inline] RIP: 0010:wb_timer_fn+0x149/0x1750 block/blk-wbt.c:360 Code: 03 80 3c 02 00 0f 85 79 13 00 00 48 8b 9b c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 90 05 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 46 13 00 00 48 8b 9b 90 05 00 00 48 b8 00 00 00 RSP: 0018:ffffc90000dc0c98 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 00000000000000b2 RSI: ffffffff83d3ea3d RDI: 0000000000000590 RBP: ffff88801abedc00 R08: 0000000000000003 R09: ffff88801abedd83 R10: ffffffff83d3ea32 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000000 R14: ffff888146638380 R15: ffff88801abedcd0 FS: 00007f081c5ce700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9c13b19c20 CR3: 00000000889fd000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 03 80 3c 02 00 0f add 0xf00023c(%rax),%eax 6: 85 79 13 test %edi,0x13(%rcx) 9: 00 00 add %al,(%rax) b: 48 8b 9b c8 00 00 00 mov 0xc8(%rbx),%rbx 12: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 19: fc ff df 1c: 48 8d bb 90 05 00 00 lea 0x590(%rbx),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 46 13 00 00 jne 0x137a 34: 48 8b 9b 90 05 00 00 mov 0x590(%rbx),%rbx 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)