divide error in tcp_rcv_space

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision
38708f29	assessment-security	DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	divide error in tcp_rcv_space_adjust (4)	2026/08/12 03:32	2026/08/12 03:32	2026/08/12 04:07	f8d35649

assessment-security

DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌

❓

divide error in tcp_rcv_space_adjust (4)

2026/08/12 03:32

2026/08/12 04:07

f8d35649

Kernel	Title	Rank 🛈	Repro	Cause bisect	Count	Last	Reported	Patched	Status
upstream	divide error in tcp_rcv_space_adjust (3) net	2	syz, C	done	3	869d	870d	27/29	fixed on 2024/08/14 22:04
upstream	divide error in tcp_rcv_space_adjust (2) net	2			1	1265d	1265d	22/29	fixed on 2023/07/01 16:05
upstream	divide error in tcp_rcv_space_adjust net	2			3	1570d	1601d	0/29	auto-closed as invalid on 2022/08/30 02:07

Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 6262 Comm: syz.4.94 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:148 [inline] RIP: 0010:tcp_rcvbuf_grow net/ipv4/tcp_input.c:-1 [inline] RIP: 0010:tcp_rcv_space_adjust+0x401/0xba0 net/ipv4/tcp_input.c:988 Code: 41 29 ec 4d 0f af f4 4d 01 f6 4d 89 f5 89 e9 4c 89 e8 48 c1 e8 20 74 0d 4c 89 e8 31 d2 48 f7 f1 49 89 c4 eb 0a 44 89 e8 31 d2 <f7> f1 41 89 c4 4c 8d ab 38 09 00 00 4c 89 e8 48 c1 e8 03 48 b9 00 RSP: 0018:ffffc90004b0f6d0 EFLAGS: 00010246 RAX: 0000000000010000 RBX: ffff8880518cce00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000066 RDI: 0000000000000067 RBP: 0000000000000000 R08: ffffffff907a2e7f R09: 1ffffffff20f45cf R10: dffffc0000000000 R11: fffffbfff20f45d0 R12: 0000000000000080 R13: 0000000000010000 R14: 0000000000010000 R15: 0000000000000100 FS: 00007fc4721c96c0(0000) GS:ffff888124de0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc471386d80 CR3: 00000000338a0000 CR4: 0000000000350ef0 Call Trace: <TASK> tcp_recvmsg_locked+0x2192/0x3770 net/ipv4/tcp.c:2880 tcp_recvmsg+0x203/0x7f0 net/ipv4/tcp.c:2944 sock_recvmsg_nosec net/socket.c:1153 [inline] sock_recvmsg+0x166/0x1e0 net/socket.c:1173 __sys_recvfrom+0x231/0x3a0 net/socket.c:2331 __do_sys_recvfrom net/socket.c:2346 [inline] __se_sys_recvfrom net/socket.c:2342 [inline] __x64_sys_recvfrom+0xde/0x100 net/socket.c:2342 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: 0033:0x7fc47139e0d9 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:00007fc4721c9028 EFLAGS: 00000246 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 00007fc471625fa0 RCX: 00007fc47139e0d9 RDX: fffffffffffffd0b RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007fc471435024 R08: 0000000000000000 R09: fffffffffffffd25 R10: 00000000c9100120 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc471626038 R14: 00007fc471625fa0 R15: 00007ffdf39a7288 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:148 [inline] RIP: 0010:tcp_rcvbuf_grow net/ipv4/tcp_input.c:-1 [inline] RIP: 0010:tcp_rcv_space_adjust+0x401/0xba0 net/ipv4/tcp_input.c:988 Code: 41 29 ec 4d 0f af f4 4d 01 f6 4d 89 f5 89 e9 4c 89 e8 48 c1 e8 20 74 0d 4c 89 e8 31 d2 48 f7 f1 49 89 c4 eb 0a 44 89 e8 31 d2 <f7> f1 41 89 c4 4c 8d ab 38 09 00 00 4c 89 e8 48 c1 e8 03 48 b9 00 RSP: 0018:ffffc90004b0f6d0 EFLAGS: 00010246 RAX: 0000000000010000 RBX: ffff8880518cce00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000066 RDI: 0000000000000067 RBP: 0000000000000000 R08: ffffffff907a2e7f R09: 1ffffffff20f45cf R10: dffffc0000000000 R11: fffffbfff20f45d0 R12: 0000000000000080 R13: 0000000000010000 R14: 0000000000010000 R15: 0000000000000100 FS: 00007fc4721c96c0(0000) GS:ffff888124de0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc471386d80 CR3: 00000000338a0000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 41 29 ec sub %ebp,%r12d 3: 4d 0f af f4 imul %r12,%r14 7: 4d 01 f6 add %r14,%r14 a: 4d 89 f5 mov %r14,%r13 d: 89 e9 mov %ebp,%ecx f: 4c 89 e8 mov %r13,%rax 12: 48 c1 e8 20 shr $0x20,%rax 16: 74 0d je 0x25 18: 4c 89 e8 mov %r13,%rax 1b: 31 d2 xor %edx,%edx 1d: 48 f7 f1 div %rcx 20: 49 89 c4 mov %rax,%r12 23: eb 0a jmp 0x2f 25: 44 89 e8 mov %r13d,%eax 28: 31 d2 xor %edx,%edx * 2a: f7 f1 div %ecx <-- trapping instruction 2c: 41 89 c4 mov %eax,%r12d 2f: 4c 8d ab 38 09 00 00 lea 0x938(%rbx),%r13 36: 4c 89 e8 mov %r13,%rax 39: 48 c1 e8 03 shr $0x3,%rax 3d: 48 rex.W 3e: b9 .byte 0xb9

Crashes (4):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Assets (help?)	Manager	Title
2026/08/27 12:47	upstream	73e3f0710014	a2b77b9e	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci-upstream-kasan-gce-root	divide error in tcp_rcv_space_adjust
2026/08/10 18:04	upstream	db2ddb871435	039457bd	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci-upstream-kasan-gce-smack-root	divide error in tcp_rcv_space_adjust
2026/08/23 09:55	upstream	2709dd5ae32f	1e72964b	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci-upstream-kasan-gce-386	divide error in tcp_rcv_space_adjust
2026/08/25 07:00	linux-next	4b18edbd8e70	23caa175	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci-upstream-linux-next-kasan-gce-root	divide error in tcp_rcv_space_adjust

Crashes (4):

Assets (help?)