general protection fault in netfs_prepare

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision
466bdce3	repro-c	Reproduced: ✅	❓	general protection fault in netfs_prepare_write	2026/08/13 11:30	2026/08/13 12:12	2026/08/13 13:36	67796a05
e70dcca3	assessment-security	DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌	❓	general protection fault in netfs_prepare_write	2026/08/09 10:28	2026/08/09 10:28	2026/08/09 11:07	5d63f80b
ef6572da	assessment-security		💥	general protection fault in netfs_prepare_write	2026/08/05 00:05	2026/08/05 00:05	2026/08/05 00:05	d4abbeac

Title	Replies (including bot)	Last reply
[syzbot] [netfs?] general protection fault in netfs_prepare_write	0 (1)	2026/08/13 14:17

Title

Replies (including bot)

Last reply

[syzbot] [netfs?] general protection fault in netfs_prepare_write

0 (1)

2026/08/13 14:17

Created	Duration	User	Patch	Repo	Result
2026/08/13 13:46	19m	nogikh@google.com		upstream	report job log log

Created

Duration

User

Patch

Repo

Result

2026/08/13 13:46

19m

nogikh@google.com

upstream

report job log log

RBP: 0000000000000006 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2bf1f9f288 R13: 0000000000000005 R14: 0000000000000000 R15: 00007f2bf1fa3252 </TASK> Oops: general protection fault, probably for non-canonical address 0xdffffc0000000015: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af] CPU: 3 UID: 0 PID: 6023 Comm: syz-executor218 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:netfs_prepare_write+0xbc/0x7b0 fs/netfs/write_issue.c:173 Code: e1 07 38 ca 7f 08 84 d2 0f 85 04 06 00 00 48 8d bb ad 00 00 00 0f b6 45 52 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 <0f> b6 14 11 48 89 f9 83 e1 07 38 ca 7f 08 84 d2 0f 85 c1 05 00 00 RSP: 0018:ffffc90003ea7b40 EFLAGS: 00010203 RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000015 RDX: dffffc0000000000 RSI: ffffffff82cb9219 RDI: 00000000000000ad RBP: ffff8880383da660 R08: 00000000ffffffff R09: fffffbfff1dbdcfe R10: ffffffff8edee7f3 R11: 0000000000000000 R12: ffff8880383da580 R13: ffff8880383da738 R14: 000000000000001c R15: ffff8880383da6b2 FS: 000055558535c400(0000) GS:ffff8880d60ec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557b8da30300 CR3: 0000000028cd1000 CR4: 0000000000352ef0 Call Trace: <TASK> netfs_unbuffered_write+0x75c/0x2020 fs/netfs/direct_write.c:111 netfs_unbuffered_write_iter_locked+0x7d6/0xa80 fs/netfs/direct_write.c:290 netfs_unbuffered_write_iter+0x442/0x720 fs/netfs/direct_write.c:382 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:409 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2bf1f5355e Code: 08 0f 85 f5 e2 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08 RSP: 002b:00007fffd127ea28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055558535c400 RCX: 00007f2bf1f5355e RDX: 0000000000000004 RSI: 00007f2bf1fa31f6 RDI: 0000000000000005 RBP: 0000000000000006 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2bf1f9f288 R13: 0000000000000005 R14: 0000000000000000 R15: 00007f2bf1fa3252 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:netfs_prepare_write+0xbc/0x7b0 fs/netfs/write_issue.c:173 Code: e1 07 38 ca 7f 08 84 d2 0f 85 04 06 00 00 48 8d bb ad 00 00 00 0f b6 45 52 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 <0f> b6 14 11 48 89 f9 83 e1 07 38 ca 7f 08 84 d2 0f 85 c1 05 00 00 RSP: 0018:ffffc90003ea7b40 EFLAGS: 00010203 RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000015 RDX: dffffc0000000000 RSI: ffffffff82cb9219 RDI: 00000000000000ad RBP: ffff8880383da660 R08: 00000000ffffffff R09: fffffbfff1dbdcfe R10: ffffffff8edee7f3 R11: 0000000000000000 R12: ffff8880383da580 R13: ffff8880383da738 R14: 000000000000001c R15: ffff8880383da6b2 FS: 000055558535c400(0000) GS:ffff8880d60ec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557b8da30300 CR3: 0000000028cd1000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: e1 07 loope 0x9 2: 38 ca cmp %cl,%dl 4: 7f 08 jg 0xe 6: 84 d2 test %dl,%dl 8: 0f 85 04 06 00 00 jne 0x612 e: 48 8d bb ad 00 00 00 lea 0xad(%rbx),%rdi 15: 0f b6 45 52 movzbl 0x52(%rbp),%eax 19: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 20: fc ff df 23: 48 89 f9 mov %rdi,%rcx 26: 48 c1 e9 03 shr $0x3,%rcx * 2a: 0f b6 14 11 movzbl (%rcx,%rdx,1),%edx <-- trapping instruction 2e: 48 89 f9 mov %rdi,%rcx 31: 83 e1 07 and $0x7,%ecx 34: 38 ca cmp %cl,%dl 36: 7f 08 jg 0x40 38: 84 d2 test %dl,%dl 3a: 0f 85 c1 05 00 00 jne 0x601

Crashes (3):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	C repro	VM info	Assets (help?)	Manager	Title
2026/08/13 14:16	upstream	3d6d817622b0	5d63f80b	.config	console log	report	C			ci-qemu-upstream	general protection fault in netfs_prepare_write
2026/08/09 05:49	upstream	06cf61899d64	5d63f80b	.config	console log	report		info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	general protection fault in netfs_prepare_write
2026/08/03 10:01	upstream	075b74841bd0	e611ffe1	.config	console log	report		info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	general protection fault in netfs_prepare_write

Crashes (3):

Assets (help?)