EXT4-fs error (device loop1): ext4_do_update_inode:5268: inode #2: comm syz.1.294: corrupted inode contents EXT4-fs error (device loop1): ext4_dirty_inode:6133: inode #2: comm syz.1.294: 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: 0 PID: 5670 Comm: syz.1.294 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:ffffc9000355f040 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880547002b0 RCX: 0000000000080000 RDX: ffffc9000e9b2000 RSI: 0000000000019d72 RDI: ffffffffffffff93 RBP: ffffc9000355f310 R08: ffff88805479e973 R09: 1ffff1100a8f3d2e R10: dffffc0000000000 R11: ffffed100a8f3d2f R12: dffffc0000000000 R13: 1ffff920006abe38 R14: ffffffffffffff8b R15: 0000000000000001 FS: 00007fdd1ecc26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffff93 CR3: 0000000023a14000 CR4: 00000000003506f0 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_append+0x2be/0x560 fs/ext4/namei.c:83 ext4_add_entry+0x8eb/0xdb0 fs/ext4/namei.c:2511 ext4_add_nondir+0x93/0x270 fs/ext4/namei.c:2845 ext4_create+0x2e6/0x470 fs/ext4/namei.c:2891 lookup_open fs/namei.c:3490 [inline] open_last_lookups fs/namei.c:3558 [inline] path_openat+0x1181/0x2ee0 fs/namei.c:3788 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 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: 0033:0x7fdd1dd9c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fdd1ecc2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fdd1e016090 RCX: 00007fdd1dd9c819 RDX: 0000000000000140 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007fdd1de32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000082 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdd1e016128 R14: 00007fdd1e016090 R15: 00007ffc7f84c198 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:ffffc9000355f040 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880547002b0 RCX: 0000000000080000 RDX: ffffc9000e9b2000 RSI: 0000000000019d72 RDI: ffffffffffffff93 RBP: ffffc9000355f310 R08: ffff88805479e973 R09: 1ffff1100a8f3d2e R10: dffffc0000000000 R11: ffffed100a8f3d2f R12: dffffc0000000000 R13: 1ffff920006abe38 R14: ffffffffffffff8b R15: 0000000000000001 FS: 00007fdd1ecc26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffff93 CR3: 0000000023a14000 CR4: 00000000003506f0 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