EXT4-fs error (device loop1): __ext4_ext_dirty:206: inode #3: comm syz.1.111: mark_inode_dirty error BUG: unable to handle page fault for address: ffffffffffffff93 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD c891067 P4D c891067 PUD c893067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 4701 Comm: syz.1.111 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline] RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline] RIP: 0010:ext4_ext_map_blocks+0x362d/0x6870 fs/ext4/extents.c:4497 Code: 18 4c 8b b4 24 60 01 00 00 4d 85 f6 0f 84 b2 00 00 00 49 8d 7e 08 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 aa 12 00 00 <41> 0f b7 46 08 c1 e0 04 48 8d 04 40 48 89 44 24 50 49 8d 46 28 48 RSP: 0018:ffffc900060f6b00 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880540cdcf8 RCX: 0000000000080000 RDX: ffffc90004189000 RSI: 0000000000026848 RDI: ffffffffffffff93 RBP: ffffc900060f6dd0 R08: ffff888070987ee3 R09: 1ffff1100e130fdc R10: dffffc0000000000 R11: ffffed100e130fdd R12: dffffc0000000000 R13: 1ffff92000c1ed90 R14: ffffffffffffff8b R15: 0000000000000001 FS: 00007f02a22946c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffff93 CR3: 00000000288ad000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_map_blocks+0x9de/0x1b70 fs/ext4/inode.c:679 ext4_getblk+0x1cc/0x6f0 fs/ext4/inode.c:890 ext4_bread+0x26/0x170 fs/ext4/inode.c:946 ext4_quota_write+0x236/0x580 fs/ext4/super.c:7222 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x312/0x660 fs/quota/quota_tree.c:136 do_insert_tree+0x22b/0x1040 fs/quota/quota_tree.c:347 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x49d/0x5d0 fs/quota/quota_tree.c:451 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6831 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0xbeb/0x1420 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5556 [inline] ext4_fill_super+0x7829/0x7dc0 fs/ext4/super.c:5687 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 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: 0033:0x7f02a139da8a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f02a2293e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f02a2293ee0 RCX: 00007f02a139da8a RDX: 0000200000000340 RSI: 0000200000000980 RDI: 00007f02a2293ea0 RBP: 0000200000000340 R08: 00007f02a2293ee0 R09: 0000000003000010 R10: 0000000003000010 R11: 0000000000000246 R12: 0000200000000980 R13: 00007f02a2293ea0 R14: 0000000000000519 R15: 0000200000000100 Modules linked in: CR2: ffffffffffffff93 ---[ end trace 0000000000000000 ]--- RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline] RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline] RIP: 0010:ext4_ext_map_blocks+0x362d/0x6870 fs/ext4/extents.c:4497 Code: 18 4c 8b b4 24 60 01 00 00 4d 85 f6 0f 84 b2 00 00 00 49 8d 7e 08 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 aa 12 00 00 <41> 0f b7 46 08 c1 e0 04 48 8d 04 40 48 89 44 24 50 49 8d 46 28 48 RSP: 0018:ffffc900060f6b00 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880540cdcf8 RCX: 0000000000080000 RDX: ffffc90004189000 RSI: 0000000000026848 RDI: ffffffffffffff93 RBP: ffffc900060f6dd0 R08: ffff888070987ee3 R09: 1ffff1100e130fdc R10: dffffc0000000000 R11: ffffed100e130fdd R12: dffffc0000000000 R13: 1ffff92000c1ed90 R14: ffffffffffffff8b R15: 0000000000000001 FS: 00007f02a22946c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffff93 CR3: 00000000288ad000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 18 4c 8b b4 sbb %cl,-0x4c(%rbx,%rcx,4) 4: 24 60 and $0x60,%al 6: 01 00 add %eax,(%rax) 8: 00 4d 85 add %cl,-0x7b(%rbp) b: f6 0f 84 testb $0x84,(%rdi) e: b2 00 mov $0x0,%dl 10: 00 00 add %al,(%rax) 12: 49 8d 7e 08 lea 0x8(%r14),%rdi 16: 48 89 f8 mov %rdi,%rax 19: 48 c1 e8 03 shr $0x3,%rax 1d: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 22: 84 c0 test %al,%al 24: 0f 85 aa 12 00 00 jne 0x12d4 * 2a: 41 0f b7 46 08 movzwl 0x8(%r14),%eax <-- trapping instruction 2f: c1 e0 04 shl $0x4,%eax 32: 48 8d 04 40 lea (%rax,%rax,2),%rax 36: 48 89 44 24 50 mov %rax,0x50(%rsp) 3b: 49 8d 46 28 lea 0x28(%r14),%rax 3f: 48 rex.W