wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
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: 4376 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Workqueue: writeback wb_workfn (flush-8:0)
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:ffffc90004476730 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888019b4da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff8f22416f R09: 1ffffffff1e4482d
R10: dffffc0000000000 R11: fffffbfff1e4482e R12: 0000000000000004
R13: 0000000000000001 R14: 1ffff11004c902de R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000054e42000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 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
 mpage_map_one_extent fs/ext4/inode.c:2437 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2490 [inline]
 ext4_writepages+0x1462/0x2fe0 fs/ext4/inode.c:2859
 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491
 __writeback_single_inode+0x153/0x1170 fs/fs-writeback.c:1688
 writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1979
 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2050
 wb_writeback+0x484/0xd40 fs/fs-writeback.c:2155
 wb_check_old_data_flush fs/fs-writeback.c:2255 [inline]
 wb_do_writeback fs/fs-writeback.c:2308 [inline]
 wb_workfn+0xb68/0xee0 fs/fs-writeback.c:2336
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
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:ffffc90004476730 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888019b4da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff8f22416f R09: 1ffffffff1e4482d
R10: dffffc0000000000 R11: fffffbfff1e4482e R12: 0000000000000004
R13: 0000000000000001 R14: 1ffff11004c902de R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a63d6ae168 CR3: 000000007eac5000 CR4: 00000000003526e0
----------------
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