general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 25619 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 RIP: 0010:PageTail include/linux/page-flags.h:292 [inline] RIP: 0010:folio_flags include/linux/page-flags.h:319 [inline] RIP: 0010:folio_test_uptodate include/linux/page-flags.h:719 [inline] RIP: 0010:ext4_mb_load_buddy_gfp+0x27a/0x1770 fs/ext4/mballoc.c:1536 Code: 00 00 e8 a9 c1 58 ff 41 bc 8b ff ff ff e9 96 05 00 00 48 89 c3 4c 8d 78 08 4d 89 fd 49 c1 ed 03 48 bd 00 00 00 00 00 fc ff df <41> 80 7c 2d 00 00 74 08 4c 89 ff e8 46 25 aa ff 4d 8b 3f 4c 89 fe RSP: 0018:ffffc90003b371b0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802520bc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff8f22416f R09: 1ffffffff1e4482d R10: dffffc0000000000 R11: fffffbfff1e4482e R12: 0000000000000000 R13: 0000000000000001 R14: 1ffff110281962de R15: 0000000000000008 FS: 000055555da1d500(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f22a0871ff8 CR3: 00000001537d3000 CR4: 00000000003506f0 DR0: 0000200000000140 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ext4_mb_load_buddy fs/ext4/mballoc.c:1641 [inline] ext4_mb_regular_allocator+0x1346/0x34a0 fs/ext4/mballoc.c:2798 ext4_mb_new_blocks+0xcf1/0x44d0 fs/ext4/mballoc.c:5793 ext4_ext_map_blocks+0x184a/0x6680 fs/ext4/extents.c:4369 ext4_map_blocks+0x9d7/0x1a90 fs/ext4/inode.c:681 ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_append+0x2bb/0x560 fs/ext4/namei.c:83 ext4_init_new_dir+0x2b8/0x550 fs/ext4/namei.c:3032 ext4_mkdir+0x4c3/0xc90 fs/ext4/namei.c:3078 vfs_mkdir+0x386/0x570 fs/namei.c:4161 do_mkdirat+0x1d8/0x440 fs/namei.c:4186 __do_sys_mkdirat fs/namei.c:4201 [inline] __se_sys_mkdirat fs/namei.c:4199 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4199 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbf5b5a8347 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff00d60a28 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fbf5b637a4b RCX: 00007fbf5b5a8347 RDX: 00000000000001ff RSI: 00007fbf5b637a4b RDI: 00000000ffffff9c RBP: 00007fbf5b8267b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007fff00d60c98 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:PageTail include/linux/page-flags.h:292 [inline] RIP: 0010:folio_flags include/linux/page-flags.h:319 [inline] RIP: 0010:folio_test_uptodate include/linux/page-flags.h:719 [inline] RIP: 0010:ext4_mb_load_buddy_gfp+0x27a/0x1770 fs/ext4/mballoc.c:1536 Code: 00 00 e8 a9 c1 58 ff 41 bc 8b ff ff ff e9 96 05 00 00 48 89 c3 4c 8d 78 08 4d 89 fd 49 c1 ed 03 48 bd 00 00 00 00 00 fc ff df <41> 80 7c 2d 00 00 74 08 4c 89 ff e8 46 25 aa ff 4d 8b 3f 4c 89 fe RSP: 0018:ffffc90003b371b0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802520bc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff8f22416f R09: 1ffffffff1e4482d R10: dffffc0000000000 R11: fffffbfff1e4482e R12: 0000000000000000 R13: 0000000000000001 R14: 1ffff110281962de R15: 0000000000000008 FS: 000055555da1d500(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc1c7796d58 CR3: 00000001537d3000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: e8 a9 c1 58 ff call 0xff58c1b0 7: 41 bc 8b ff ff ff mov $0xffffff8b,%r12d d: e9 96 05 00 00 jmp 0x5a8 12: 48 89 c3 mov %rax,%rbx 15: 4c 8d 78 08 lea 0x8(%rax),%r15 19: 4d 89 fd mov %r15,%r13 1c: 49 c1 ed 03 shr $0x3,%r13 20: 48 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%rbp 27: fc ff df * 2a: 41 80 7c 2d 00 00 cmpb $0x0,0x0(%r13,%rbp,1) <-- trapping instruction 30: 74 08 je 0x3a 32: 4c 89 ff mov %r15,%rdi 35: e8 46 25 aa ff call 0xffaa2580 3a: 4d 8b 3f mov (%r15),%r15 3d: 4c 89 fe mov %r15,%rsi