BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1e1556067 P4D 1e1556067 PUD 1e5531067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 5513 Comm: syz-executor.3 Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202 RAX: ffffffff8154d7aa RBX: 0000000000000101 RCX: ffff8881ed57de80 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881d79371c0 RBP: ffff8881f6f09ec8 R08: ffffffff8154d3ee R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffe060 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d79371c0 FS: 00007faa2853c6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001cf5e7000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: call_timer_fn+0x36/0x390 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x879/0xbe0 kernel/time/timer.c:1817 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x195/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:538 [inline] smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:crc32_body lib/crc32.c:121 [inline] RIP: 0010:crc32_le_generic lib/crc32.c:179 [inline] RIP: 0010:__crc32c_le_base+0xa41/0xd20 lib/crc32.c:202 Code: ff ff e8 22 b0 32 ff e9 2b f6 ff ff e8 18 b0 32 ff e9 c1 fd ff ff e8 0e b0 32 ff e9 17 f6 ff ff e8 04 b0 32 ff e9 ad fd ff ff <89> e9 80 e1 07 38 c1 0f 8c dc fa ff ff 48 89 ef e8 ca 94 62 ff 48 RSP: 0018:ffff8881e5406fd8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000002 RBX: 000000006c811366 RCX: 0000000000040000 RDX: dffffc0000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffff8881e5407300 R08: ffffffff823186e4 R09: ffffffff84fa8cd0 R10: ffffffff84fa8848 R11: ffffffff84fa87f8 R12: 0000000000000002 R13: 0000000000000002 R14: 0000000000000002 R15: ffff8881e54072fc chksum_update+0x42/0x90 crypto/crc32c_generic.c:90 crypto_shash_update+0x1db/0x2a0 crypto/shash.c:132 ext4_chksum fs/ext4/ext4.h:2145 [inline] ext4_inode_csum+0x30b/0xc80 fs/ext4/inode.c:64 ext4_inode_csum_set fs/ext4/inode.c:117 [inline] ext4_do_update_inode fs/ext4/inode.c:5511 [inline] ext4_mark_iloc_dirty+0x1ea6/0x3560 fs/ext4/inode.c:6071 ext4_orphan_del+0x6f7/0x7b0 fs/ext4/namei.c:3209 ext4_truncate+0xd09/0x1290 fs/ext4/inode.c:4661 ext4_setattr+0xeb5/0x1500 fs/ext4/inode.c:5857 notify_change+0xc00/0xeb0 fs/attr.c:354 do_truncate+0x1ed/0x2d0 fs/open.c:64 handle_truncate fs/namei.c:3154 [inline] do_last fs/namei.c:3571 [inline] path_openat+0x2e0f/0x34b0 fs/namei.c:3683 do_filp_open+0x20b/0x450 fs/namei.c:3713 do_sys_open+0x39c/0x810 fs/open.c:1123 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7faa291c1ea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007faa2853c0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007faa292f8f80 RCX: 00007faa291c1ea9 RDX: 0000000000007a05 RSI: 0000000020000380 RDI: ffffffffffffff9c RBP: 00007faa29230ff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001700 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007faa292f8f80 R15: 00007ffe40ad74c8 Modules linked in: CR2: 0000000000000000 ---[ end trace 68ede3368a82bf25 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202 RAX: ffffffff8154d7aa RBX: 0000000000000101 RCX: ffff8881ed57de80 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881d79371c0 RBP: ffff8881f6f09ec8 R08: ffffffff8154d3ee R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffe060 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d79371c0 FS: 00007faa2853c6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001cf5e7000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: e8 22 b0 32 ff call 0xff32b027 5: e9 2b f6 ff ff jmp 0xfffff635 a: e8 18 b0 32 ff call 0xff32b027 f: e9 c1 fd ff ff jmp 0xfffffdd5 14: e8 0e b0 32 ff call 0xff32b027 19: e9 17 f6 ff ff jmp 0xfffff635 1e: e8 04 b0 32 ff call 0xff32b027 23: e9 ad fd ff ff jmp 0xfffffdd5 * 28: 89 e9 mov %ebp,%ecx <-- trapping instruction 2a: 80 e1 07 and $0x7,%cl 2d: 38 c1 cmp %al,%cl 2f: 0f 8c dc fa ff ff jl 0xfffffb11 35: 48 89 ef mov %rbp,%rdi 38: e8 ca 94 62 ff call 0xff629507 3d: 48 rex.W