BUG: unable to handle kernel paging request in ext4_free_ext

Date	Name	Commit	Repro	Result
2026/03/27	linux-6.6.y (ToT)	c09fbcd31ae6	C	[report] BUG: unable to handle kernel paging request in ext4_free_ext_path
2026/03/27	upstream (ToT)	46b513250491	C	Didn't crash

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.1	BUG: unable to handle kernel paging request in ext4_free_ext_path	8	C			7	4d16h	4d22h	0/3	upstream: reported C repro on 2026/03/25 14:06

Kernel

Title

Rank 🛈

linux-6.1

BUG: unable to handle kernel paging request in ext4_free_ext_path

4d16h

4d22h

0/3

upstream: reported C repro on 2026/03/25 14:06

Created	Duration	User	Patch	Repo	Result
2026/03/29 14:30	1m	fix candidate		upstream	error job log

Created

Duration

User

Patch

Repo

Result

2026/03/29 14:30

fix candidate

upstream

error job log

syz.0.17[5920]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set loop0: detected capacity change from 0 to 128 EXT4-fs (loop0): mounted filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09 r/w without journal. Quota mode: none. ext4 filesystem being mounted at /0/file0aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa supports timestamps until 2038-01-19 (0x7fffffff) BUG: unable to handle page fault for address: ffffffffffffffec #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD cf35067 P4D cf35067 PUD cf37067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5920 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline] RIP: 0010:ext4_free_ext_path+0x45/0x110 fs/ext4/extents.c:128 Code: 85 db 0f 84 b0 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 f8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 a9 00 00 00 <0f> b7 43 08 c1 e0 04 48 8d 04 40 48 89 44 24 08 48 8d 43 28 48 89 RSP: 0018:ffffc900020af638 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffffffffffe4 RCX: ffff88802b548000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffffffffffec RBP: ffffc900020af758 R08: ffff88805e93821f R09: 1ffff1100bd27043 R10: dffffc0000000000 R11: ffffed100bd27044 R12: ffff88805e9382b0 R13: ffffffffffffffe4 R14: dffffc0000000000 R15: dffffc0000000000 FS: 000055557ab4e500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffec CR3: 0000000030129000 CR4: 00000000003506f0 Call Trace: <TASK> finish_range+0x234/0x340 fs/ext4/migrate.c:60 update_extent_range fs/ext4/migrate.c:83 [inline] update_ind_extent_range+0x2e3/0x520 fs/ext4/migrate.c:106 ext4_ext_migrate+0xb07/0x1080 fs/ext4/migrate.c:522 __ext4_ioctl fs/ext4/ioctl.c:1412 [inline] ext4_ioctl+0x1ee3/0x3b80 fs/ext4/ioctl.c:1630 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f87ab99c799 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:00007fff647e3a48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f87abc15fa0 RCX: 00007f87ab99c799 RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000004 RBP: 00007f87aba32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87abc15fac R14: 00007f87abc15fa0 R15: 00007f87abc15fa0 </TASK> Modules linked in: CR2: ffffffffffffffec ---[ end trace 0000000000000000 ]--- RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline] RIP: 0010:ext4_free_ext_path+0x45/0x110 fs/ext4/extents.c:128 Code: 85 db 0f 84 b0 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 f8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 a9 00 00 00 <0f> b7 43 08 c1 e0 04 48 8d 04 40 48 89 44 24 08 48 8d 43 28 48 89 RSP: 0018:ffffc900020af638 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffffffffffe4 RCX: ffff88802b548000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffffffffffec RBP: ffffc900020af758 R08: ffff88805e93821f R09: 1ffff1100bd27043 R10: dffffc0000000000 R11: ffffed100bd27044 R12: ffff88805e9382b0 R13: ffffffffffffffe4 R14: dffffc0000000000 R15: dffffc0000000000 FS: 000055557ab4e500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffec CR3: 0000000030129000 CR4: 00000000003506f0 ---------------- Code disassembly (best guess): 0: 85 db test %ebx,%ebx 2: 0f 84 b0 00 00 00 je 0xb8 8: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15 f: fc ff df 12: 48 8d 7b 08 lea 0x8(%rbx),%rdi 16: 48 89 f8 mov %rdi,%rax 19: 48 c1 e8 03 shr $0x3,%rax 1d: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax 22: 84 c0 test %al,%al 24: 0f 85 a9 00 00 00 jne 0xd3 * 2a: 0f b7 43 08 movzwl 0x8(%rbx),%eax <-- trapping instruction 2e: c1 e0 04 shl $0x4,%eax 31: 48 8d 04 40 lea (%rax,%rax,2),%rax 35: 48 89 44 24 08 mov %rax,0x8(%rsp) 3a: 48 8d 43 28 lea 0x28(%rbx),%rax 3e: 48 rex.W 3f: 89 .byte 0x89

Crashes (4):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/03/27 02:28	linux-6.6.y	c09fbcd31ae6	766b6434	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)]	ci2-linux-6-6-kasan	BUG: unable to handle kernel paging request in ext4_free_ext_path
2026/03/27 01:46	linux-6.6.y	c09fbcd31ae6	766b6434	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)]	ci2-linux-6-6-kasan	BUG: unable to handle kernel paging request in ext4_free_ext_path
2026/03/25 19:28	linux-6.6.y	c09fbcd31ae6	8ee77f7d	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-linux-6-6-kasan	BUG: unable to handle kernel paging request in ext4_free_ext_path
2026/03/25 19:28	linux-6.6.y	c09fbcd31ae6	8ee77f7d	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-linux-6-6-kasan	BUG: unable to handle kernel paging request in ext4_free_ext_path

Crashes (4):

Assets (help?)