BUG: kernel NULL pointer dereference, address: 0000000000000012 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 27895067 P4D 27895067 PUD 20efb067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 UID: 0 PID: 6141 Comm: syz.0.52 Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:___slab_alloc+0x595/0x14a0 mm/slub.c:3773 Code: 85 fb 00 00 00 65 4c 8b 2c 25 00 d6 03 00 4c 89 6b 28 49 83 7e 10 00 0f 85 82 01 00 00 49 8b 5e 18 48 85 db 0f 84 ea 04 00 00 <48> 8b 43 10 49 89 46 18 8b 4c 24 10 83 f9 ff 74 15 48 8b 03 48 83 RSP: 0018:ffffc90003bc76c8 EFLAGS: 00010002 RAX: 56cf4227fe66d200 RBX: 0000000000000002 RCX: ffff888026fae4d8 RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5fb0e0 RBP: 0000000000000202 R08: ffffffff942a4887 R09: 1ffffffff2854910 R10: dffffc0000000000 R11: fffffbfff2854911 R12: ffff88802e787dc0 R13: ffff888026fada00 R14: ffffe8ffffd7e610 R15: ffffffff81faafdf FS: 00007f14759d06c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 0000000012560000 CR4: 0000000000350ef0 Call Trace: __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4175 ext4_mb_add_groupinfo+0x6c3/0xfa0 fs/ext4/mballoc.c:3356 ext4_mb_init_backend fs/ext4/mballoc.c:3435 [inline] ext4_mb_init+0x15ab/0x27e0 fs/ext4/mballoc.c:3733 __ext4_fill_super fs/ext4/super.c:5559 [inline] ext4_fill_super+0x5f54/0x6e60 fs/ext4/super.c:5733 get_tree_bdev_flags+0x48e/0x5c0 fs/super.c:1636 vfs_get_tree+0x92/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1474b874ca Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f14759cfe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f14759cfef0 RCX: 00007f1474b874ca RDX: 0000000020000180 RSI: 0000000020000280 RDI: 00007f14759cfeb0 RBP: 0000000020000180 R08: 00007f14759cfef0 R09: 0000000000000008 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000020000280 R13: 00007f14759cfeb0 R14: 000000000000048f R15: 0000000020000700 Modules linked in: CR2: 0000000000000012 ---[ end trace 0000000000000000 ]--- RIP: 0010:___slab_alloc+0x595/0x14a0 mm/slub.c:3773 Code: 85 fb 00 00 00 65 4c 8b 2c 25 00 d6 03 00 4c 89 6b 28 49 83 7e 10 00 0f 85 82 01 00 00 49 8b 5e 18 48 85 db 0f 84 ea 04 00 00 <48> 8b 43 10 49 89 46 18 8b 4c 24 10 83 f9 ff 74 15 48 8b 03 48 83 RSP: 0018:ffffc90003bc76c8 EFLAGS: 00010002 RAX: 56cf4227fe66d200 RBX: 0000000000000002 RCX: ffff888026fae4d8 RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5fb0e0 RBP: 0000000000000202 R08: ffffffff942a4887 R09: 1ffffffff2854910 R10: dffffc0000000000 R11: fffffbfff2854911 R12: ffff88802e787dc0 R13: ffff888026fada00 R14: ffffe8ffffd7e610 R15: ffffffff81faafdf FS: 00007f14759d06c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 0000000012560000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 85 fb test %edi,%ebx 2: 00 00 add %al,(%rax) 4: 00 65 4c add %ah,0x4c(%rbp) 7: 8b 2c 25 00 d6 03 00 mov 0x3d600,%ebp e: 4c 89 6b 28 mov %r13,0x28(%rbx) 12: 49 83 7e 10 00 cmpq $0x0,0x10(%r14) 17: 0f 85 82 01 00 00 jne 0x19f 1d: 49 8b 5e 18 mov 0x18(%r14),%rbx 21: 48 85 db test %rbx,%rbx 24: 0f 84 ea 04 00 00 je 0x514 * 2a: 48 8b 43 10 mov 0x10(%rbx),%rax <-- trapping instruction 2e: 49 89 46 18 mov %rax,0x18(%r14) 32: 8b 4c 24 10 mov 0x10(%rsp),%ecx 36: 83 f9 ff cmp $0xffffffff,%ecx 39: 74 15 je 0x50 3b: 48 8b 03 mov (%rbx),%rax 3e: 48 rex.W 3f: 83 .byte 0x83