Hello, when using Healer to fuzz the latest Linux Kernel, the following crash was triggered on: HEAD commit: e8f897f4afef0031fe618a8e94127a0934896aba (tag: v6.8) git tree: upstream console output: https://pastebin.com/raw/YBKrQHxW kernel config: https://pastebin.com/raw/SJFReJfc C reproducer: https://pastebin.com/raw/GUVzwEmx Syzlang reproducer: https://pastebin.com/raw/9KqQRP2e If you fix this issue, please add the following tag to the commit: Reported-by: Qiang Zhang <zzqq0103.hey@xxxxxxxxx> ---------------------------------------------------------- ------------[ cut here ]------------ kernel BUG at fs/ext4/extents.c:3180! invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 267 Comm: syz-executor349 Tainted: G B 6.8.0 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:ext4_split_extent_at+0x8bf/0xdb0 fs/ext4/extents.c:3180 Code: 25 28 00 00 00 0f 85 68 04 00 00 48 81 c4 d8 00 00 00 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 02 78 90 02 e8 22 9c a6 ff 90 <0f> 0b e8 1a 9c a6 ff 48 8b 5c 24 28 8b 6c 24 30 48 b8 00 00 00 00 RSP: 0018:ffff88810e12f720 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000001ff7fdfd RCX: ffffffffb0dfc90e RDX: ffff88810ea54400 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000050000028 R10: 000000001ff7fdfd R11: 6e696c6261736944 R12: ffff8881031efff8 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88810c226980 FS: 00005555561ad3c0(0000) GS:ffff88811af00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d9033a180 CR3: 000000010e0b2001 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> ext4_force_split_extent_at fs/ext4/extents.c:338 [inline] ext4_ext_remove_space+0x283d/0x3ba0 fs/ext4/extents.c:2875 ext4_punch_hole+0xce0/0xfa0 fs/ext4/inode.c:3994 ext4_fallocate+0xd02/0x3760 fs/ext4/extents.c:4741 vfs_fallocate+0x4a1/0xd00 fs/open.c:328 ioctl_preallocate+0x192/0x210 fs/ioctl.c:291 file_ioctl fs/ioctl.c:334 [inline] do_vfs_ioctl+0x1262/0x15b0 fs/ioctl.c:850 __do_sys_ioctl fs/ioctl.c:869 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x110/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xb3/0x1b0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fd0ed76317d Code: c3 e8 d7 21 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd48ca3738 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd0ed76317d RDX: 0000000020000080 RSI: 0000000040305829 RDI: 0000000000000004 RBP: 0000000000000001 R08: 00007ffd48ca3938 R09: 00007ffd48ca3938 R10: 00007ffd48ca3938 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd48ca3928 R14: 00007fd0ed7e2530 R15: 0000000000000001 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ext4_split_extent_at+0x8bf/0xdb0 fs/ext4/extents.c:3180 Code: 25 28 00 00 00 0f 85 68 04 00 00 48 81 c4 d8 00 00 00 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 02 78 90 02 e8 22 9c a6 ff 90 <0f> 0b e8 1a 9c a6 ff 48 8b 5c 24 28 8b 6c 24 30 48 b8 00 00 00 00 RSP: 0018:ffff88810e12f720 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000001ff7fdfd RCX: ffffffffb0dfc90e RDX: ffff88810ea54400 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000050000028 R10: 000000001ff7fdfd R11: 6e696c6261736944 R12: ffff8881031efff8 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88810c226980 FS: 00005555561ad3c0(0000) GS:ffff88811af00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d9033a180 CR3: 000000010e0b2001 CR4: 0000000000770ef0 PKRU: 55555554