Re: [syzbot] [rdma?] WARNING in rxe_skb_tx_dtor

[syzbot <syzbot+8425ccfb599521edb153@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in rxe_skb_tx_dtor

Oops: general protection fault, probably for non-canonical address 0xe000bc000000006c: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x0006000000000360-0x0006000000000367]
CPU: 0 UID: 0 PID: 1088 Comm: kworker/u4:10 Not tainted 6.16.0-rc3-syzkaller-g907cb0dfd322 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: rxe_wq do_work
RIP: 0010:rxe_skb_tx_dtor+0x78/0x240 drivers/infiniband/sw/rxe/rxe_net.c:364
Code: 03 42 80 3c 28 00 74 08 4c 89 f7 e8 72 65 81 f9 4d 8b 36 4d 85 f6 0f 84 c3 00 00 00 4d 8d be 60 03 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 77 01 00 00 41 8b 2f 31 ff 89 ee e8 bf
RSP: 0018:ffffc900000079e8 EFLAGS: 00010206
RAX: 0000c0000000006c RBX: ffff88804e71d140 RCX: ffff8880357ac880
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff88804e71d140
RBP: 0000000000000000 R08: ffffffff8fa10ef7 R09: 1ffffffff1f421de
R10: dffffc0000000000 R11: ffffffff88a26c60 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0006000000000000 R15: 0006000000000360
FS:  0000000000000000(0000) GS:ffff88808d250000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9de1ffdfc8 CR3: 00000000441ff000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 skb_release_head_state+0x101/0x250 net/core/skbuff.c:1139
 napi_consume_skb+0xd2/0x1e0 net/core/skbuff.c:-1
 e1000_unmap_and_free_tx_resource drivers/net/ethernet/intel/e1000/e1000_main.c:1972 [inline]
 e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3864 [inline]
 e1000_clean+0x49d/0x2b00 drivers/net/ethernet/intel/e1000/e1000_main.c:3805
 __napi_poll+0xc7/0x480 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x707/0xe30 net/core/dev.c:7605
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 do_softirq+0xec/0x180 kernel/softirq.c:480
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
 __dev_queue_xmit+0x1cd7/0x3a70 net/core/dev.c:4740
 neigh_output include/net/neighbour.h:539 [inline]
 ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
 ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226
 rxe_send drivers/infiniband/sw/rxe/rxe_net.c:390 [inline]
 rxe_xmit_packet+0x79e/0xa30 drivers/infiniband/sw/rxe/rxe_net.c:449
 rxe_requester+0x1fea/0x3d20 drivers/infiniband/sw/rxe/rxe_req.c:805
 rxe_sender+0x16/0x50 drivers/infiniband/sw/rxe/rxe_req.c:839
 do_task drivers/infiniband/sw/rxe/rxe_task.c:127 [inline]
 do_work+0x1b1/0x6c0 drivers/infiniband/sw/rxe/rxe_task.c:187
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:rxe_skb_tx_dtor+0x78/0x240 drivers/infiniband/sw/rxe/rxe_net.c:364
Code: 03 42 80 3c 28 00 74 08 4c 89 f7 e8 72 65 81 f9 4d 8b 36 4d 85 f6 0f 84 c3 00 00 00 4d 8d be 60 03 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 77 01 00 00 41 8b 2f 31 ff 89 ee e8 bf
RSP: 0018:ffffc900000079e8 EFLAGS: 00010206
RAX: 0000c0000000006c RBX: ffff88804e71d140 RCX: ffff8880357ac880
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff88804e71d140
RBP: 0000000000000000 R08: ffffffff8fa10ef7 R09: 1ffffffff1f421de
R10: dffffc0000000000 R11: ffffffff88a26c60 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0006000000000000 R15: 0006000000000360
FS:  0000000000000000(0000) GS:ffff88808d250000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9de1ffdfc8 CR3: 00000000441ff000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	03 42 80             	add    -0x80(%rdx),%eax
   3:	3c 28                	cmp    $0x28,%al
   5:	00 74 08 4c          	add    %dh,0x4c(%rax,%rcx,1)
   9:	89 f7                	mov    %esi,%edi
   b:	e8 72 65 81 f9       	call   0xf9816582
  10:	4d 8b 36             	mov    (%r14),%r14
  13:	4d 85 f6             	test   %r14,%r14
  16:	0f 84 c3 00 00 00    	je     0xdf
  1c:	4d 8d be 60 03 00 00 	lea    0x360(%r14),%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 77 01 00 00    	jne    0x1ae
  37:	41 8b 2f             	mov    (%r15),%ebp
  3a:	31 ff                	xor    %edi,%edi
  3c:	89 ee                	mov    %ebp,%esi
  3e:	e8                   	.byte 0xe8
  3f:	bf                   	.byte 0xbf


Tested on:

commit:         907cb0df RDNA/rxe: Fix rxe_skb_tx_dtor problem
git tree:       https://github.com/zhuyj/linux.git v6.16_fix_rxe_skb_tx_dtor
console output: https://syzkaller.appspot.com/x/log.txt?x=109be08c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=79da270cec5ffd65
dashboard link: https://syzkaller.appspot.com/bug?extid=8425ccfb599521edb153
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6

Note: no patches were applied.