WARNING in iomap_read_inline_data (2)

Status: upstream: reported on 2026/09/15 03:40
Subsystems: iomap
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+079e16bc964fb91acb4a@syzkaller.appspotmail.com
First crash: 4d00h, last: 4d00h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
6d088c9f assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in iomap_read_inline_data (2) 2026/09/13 00:54 2026/09/13 00:54 2026/09/13 01:23 70a60e12
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [iomap?] WARNING in iomap_read_inline_data (2) 0 (1) 2026/09/15 03:40
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in iomap_read_inline_data gfs2 iomap -1 syz, C 3 1367d 1385d 22/29 fixed on 2023/02/24 13:50

Sample crash report:
------------[ cut here ]------------
size > iomap->length
WARNING: fs/iomap/buffered-io.c:431 at iomap_read_inline_data+0xa7b/0xc40 fs/iomap/buffered-io.c:431, CPU#0: syz.0.0/5317
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:iomap_read_inline_data+0xa7b/0xc40 fs/iomap/buffered-io.c:431
Code: 48 83 c4 58 5b 41 5c 41 5d 41 5e 41 5f 5d e9 0c 45 78 09 cc e8 46 17 56 ff 90 0f 0b 90 bd fb ff ff ff eb da e8 36 17 56 ff 90 <0f> 0b 90 48 bb 00 00 00 00 00 fc ff df 48 8b 44 24 10 80 3c 18 00
RSP: 0018:ffffc9000e5172d8 EFLAGS: 00010293
RAX: ffffffff8271c46a RBX: ffffc9000e517538 RCX: ffff88803ecccb00
RDX: 0000000000000000 RSI: 0000000000000015 RDI: 0000000000000200
RBP: 0000000000001000 R08: ffffea00004e0fc7 R09: 1ffffd400009c1f8
R10: dffffc0000000000 R11: fffff9400009c1f9 R12: ffffc9000e5174e0
R13: ffffea00004e0fc0 R14: 0000000000000015 R15: 1ffff92001ca2ea7
FS:  00007fe7bb50d6c0(0000) GS:ffff88808c2c7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f481c6085a1 CR3: 000000001201b000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 iomap_read_folio_iter+0x30d/0xe80 fs/iomap/buffered-io.c:571
 iomap_read_folio+0x58b/0x970 fs/iomap/buffered-io.c:676
 ntfs_read_folio+0x3f1/0x4b0 fs/ntfs3/inode.c:856
 filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2520
 filemap_fault+0xd06/0x13b0 mm/filemap.c:3689
 __do_fault+0x138/0x2a0 mm/memory.c:5565
 do_shared_fault mm/memory.c:6064 [inline]
 do_fault mm/memory.c:6138 [inline]
 do_pte_missing+0x684/0x34b0 mm/memory.c:4700
 handle_pte_fault mm/memory.c:6558 [inline]
 __handle_mm_fault mm/memory.c:6707 [inline]
 handle_mm_fault+0x1a53/0x3750 mm/memory.c:6876
 do_user_addr_fault+0x746/0x1340 arch/x86/mm/fault.c:1394
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0010:__put_user_4+0xd/0x30 arch/x86/lib/putuser.S:94
Code: 66 89 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <89> 01 31 c9 0f 01 ca e9 c7 95 03 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000e517e50 EFLAGS: 00050246
RAX: 000000000000002a RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000085a7cfd RSI: ffffffff8e702abd RDI: ffffffff8c6dba80
RBP: 000000000000002a R08: ffffffff82205d8f R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1003a3b181 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000005
 __sys_socketpair+0xb7/0x560 net/socket.c:1868
 __do_sys_socketpair net/socket.c:1934 [inline]
 __se_sys_socketpair net/socket.c:1931 [inline]
 __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1931
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe7ba59e159
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:00007fe7bb50cfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007fe7ba826180 RCX: 00007fe7ba59e159
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001
RBP: 00007fe7ba63503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7ba826218 R14: 00007fe7ba826180 R15: 00007ffc20525218
 </TASK>
----------------
Code disassembly (best guess):
   0:	66 89 01             	mov    %ax,(%rcx)
   3:	31 c9                	xor    %ecx,%ecx
   5:	0f 01 ca             	clac
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	48 89 cb             	mov    %rcx,%rbx
  20:	48 c1 fb 3f          	sar    $0x3f,%rbx
  24:	48 09 d9             	or     %rbx,%rcx
  27:	0f 01 cb             	stac
* 2a:	89 01                	mov    %eax,(%rcx) <-- trapping instruction
  2c:	31 c9                	xor    %ecx,%ecx
  2e:	0f 01 ca             	clac
  31:	e9 c7 95 03 00       	jmp    0x395fd
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/11 03:37 upstream 50d05c7c76c9 1fe56c0a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in iomap_read_inline_data
* Struck through repros no longer work on HEAD.