Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067] CPU: 1 UID: 0 PID: 83 Comm: kworker/u8:5 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Workqueue: writeback wb_workfn (flush-7:2) RIP: 0010:f2fs_dev_is_alloc_blocked fs/f2fs/segment.h:956 [inline] RIP: 0010:get_new_segment fs/f2fs/segment.c:2964 [inline] RIP: 0010:new_curseg+0x1134/0x3580 fs/f2fs/segment.c:3110 Code: e8 41 93 cd fd 48 8b 7c 24 30 48 8b 07 49 6b cf 70 4c 8d 34 08 49 83 c6 61 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 73 11 00 00 41 80 3e 00 0f 84 e6 00 00 00 RSP: 0018:ffffc900024be608 EFLAGS: 00010216 RAX: 000000000000000c RBX: 0000000000008000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000008000 RDI: ffff88807b455a88 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000497cb0 R12: ffff888051690000 R13: 0000000000000004 R14: 0000000000000061 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123bbf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3390fff8 CR3: 000000007b486000 CR4: 0000000000350ef0 Call Trace: f2fs_allocate_data_block+0x229c/0x43c0 fs/f2fs/segment.c:3979 do_write_page+0x13f/0x880 fs/f2fs/segment.c:4099 f2fs_outplace_write_data+0x11a/0x220 fs/f2fs/segment.c:4175 f2fs_do_write_data_page+0x1150/0x1540 fs/f2fs/data.c:3048 f2fs_write_single_data_page+0x9cc/0x1840 fs/f2fs/data.c:3165 f2fs_write_cache_pages fs/f2fs/data.c:3427 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3603 [inline] f2fs_write_data_pages+0x1d2e/0x36f0 fs/f2fs/data.c:3641 do_writepages+0x338/0x560 mm/page-writeback.c:2560 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1803 writeback_sb_inodes+0x9de/0x1b00 fs/fs-writeback.c:2114 wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2299 wb_do_writeback fs/fs-writeback.c:2467 [inline] wb_workfn+0x431/0x10f0 fs/fs-writeback.c:2512 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:f2fs_dev_is_alloc_blocked fs/f2fs/segment.h:956 [inline] RIP: 0010:get_new_segment fs/f2fs/segment.c:2964 [inline] RIP: 0010:new_curseg+0x1134/0x3580 fs/f2fs/segment.c:3110 Code: e8 41 93 cd fd 48 8b 7c 24 30 48 8b 07 49 6b cf 70 4c 8d 34 08 49 83 c6 61 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 73 11 00 00 41 80 3e 00 0f 84 e6 00 00 00 RSP: 0018:ffffc900024be608 EFLAGS: 00010216 RAX: 000000000000000c RBX: 0000000000008000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000008000 RDI: ffff88807b455a88 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000497cb0 R12: ffff888051690000 R13: 0000000000000004 R14: 0000000000000061 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123bbf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3390fff8 CR3: 000000007b486000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: e8 41 93 cd fd call 0xfdcd9346 5: 48 8b 7c 24 30 mov 0x30(%rsp),%rdi a: 48 8b 07 mov (%rdi),%rax d: 49 6b cf 70 imul $0x70,%r15,%rcx 11: 4c 8d 34 08 lea (%rax,%rcx,1),%r14 15: 49 83 c6 61 add $0x61,%r14 19: 4c 89 f0 mov %r14,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 73 11 00 00 jne 0x11a9 36: 41 80 3e 00 cmpb $0x0,(%r14) 3a: 0f 84 e6 00 00 00 je 0x126