[syzbot ci] Re: swiotlb: avoid swiotlb copy on network sockets

[syzbot ci <syzbot+ci194162eefbbbb459@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v2] swiotlb: avoid swiotlb copy on network sockets
https://lore.kernel.org/all/20260824152932.1583506-1-lrizzo@google.com
* [PATCH v2 1/5] swiotlb: enforce pool nareas and nslabs invariants
* [PATCH v2 2/5] swiotlb/mm: Implement SWIOTLB nocopy page allocator
* [PATCH v2 3/5] net/swiotlb: Track bounce device per socket
* [PATCH v2 4/5] net: Divert socket allocations to SWIOTLB for nocopy TX
* [PATCH v2 5/5] swiotlb: Implement RX nocopy with fast recycling eviction

and found the following issue:
general protection fault in page_pool_put_unrefed_netmem

Full report is available here:
https://ci.syzbot.org/series/b17756c4-983f-4d7a-8415-3da06c0dda99

***

general protection fault in page_pool_put_unrefed_netmem

tree:      torvalds
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base:      0a0d1d55dad570724bf8c7ea83409639cfb4be9b
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/20e51ca2-88da-4674-9797-a62c64743095/config
syz repro: https://ci.syzbot.org/findings/4385dd7f-d1fc-4627-ad19-6862c780a90c/syz_repro

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000082: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000410-0x0000000000000417]
CPU: 0 UID: 0 PID: 5836 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:swiotlb_addr_in_default_pool include/linux/swiotlb.h:177 [inline]
RIP: 0010:swiotlb_is_nocopy_addr include/linux/swiotlb.h:184 [inline]
RIP: 0010:__page_pool_put_page net/core/page_pool.c:851 [inline]
RIP: 0010:page_pool_put_unrefed_netmem+0x22a/0xd20 net/core/page_pool.c:930
Code: 5c 63 00 00 89 c5 31 ff 89 c6 e8 61 17 04 f8 85 ed 0f 84 07 08 00 00 e8 54 12 04 f8 49 81 c4 10 04 00 00 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 37 c7 73 f8 4d 8b 24 24 4d 85 e4
RSP: 0018:ffffc900039df230 EFLAGS: 00010206
RAX: 0000000000000082 RBX: 0000000000000000 RCX: ffff888160efda00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff89c3aca5 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5a4e0 R12: 0000000000000410
R13: dffffc0000000000 R14: ffffea0004450300 R15: 0000000004450300
FS:  00007f08f83e86c0(0000) GS:ffff88818d6fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd455a8fe8 CR3: 00000001134ac000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 page_pool_put_netmem include/net/page_pool/helpers.h:343 [inline]
 page_pool_put_full_netmem include/net/page_pool/helpers.h:373 [inline]
 napi_pp_put_page+0x133/0x1e0 net/core/skbuff.c:1036
 skb_pp_recycle net/core/skbuff.c:1047 [inline]
 skb_free_head net/core/skbuff.c:1091 [inline]
 skb_release_data+0x8c3/0xab0 net/core/skbuff.c:1122
 skb_release_all net/core/skbuff.c:1197 [inline]
 __kfree_skb+0x5d/0x210 net/core/skbuff.c:1211
 llc_rcv+0x77a/0xcb0 net/llc/llc_input.c:-1
 __netif_receive_skb_list_ptype net/core/dev.c:6312 [inline]
 __netif_receive_skb_list_core+0x784/0x830 net/core/dev.c:6354
 __netif_receive_skb_list net/core/dev.c:6406 [inline]
 netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6497
 netif_receive_skb_list+0x67/0x480 net/core/dev.c:6549
 xdp_recv_frames net/bpf/test_run.c:268 [inline]
 xdp_test_run_batch net/bpf/test_run.c:349 [inline]
 bpf_test_run_xdp_live+0x1875/0x1c20 net/bpf/test_run.c:378
 bpf_prog_test_run_xdp+0x7d8/0x11d0 net/bpf/test_run.c:1463
 bpf_prog_test_run+0x2c5/0x340 kernel/bpf/syscall.c:4804
 __sys_bpf+0xa22/0xd90 kernel/bpf/syscall.c:6385
 __do_sys_bpf kernel/bpf/syscall.c:6486 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6483 [inline]
 __x64_sys_bpf+0xba/0xd0 kernel/bpf/syscall.c:6483
 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: 0033:0x7f08f759e0d9
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:00007f08f83e8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f08f7825fa0 RCX: 00007f08f759e0d9
RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a
RBP: 00007f08f7635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08f7826038 R14: 00007f08f7825fa0 R15: 00007fffc4c69778
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:swiotlb_addr_in_default_pool include/linux/swiotlb.h:177 [inline]
RIP: 0010:swiotlb_is_nocopy_addr include/linux/swiotlb.h:184 [inline]
RIP: 0010:__page_pool_put_page net/core/page_pool.c:851 [inline]
RIP: 0010:page_pool_put_unrefed_netmem+0x22a/0xd20 net/core/page_pool.c:930
Code: 5c 63 00 00 89 c5 31 ff 89 c6 e8 61 17 04 f8 85 ed 0f 84 07 08 00 00 e8 54 12 04 f8 49 81 c4 10 04 00 00 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 37 c7 73 f8 4d 8b 24 24 4d 85 e4
RSP: 0018:ffffc900039df230 EFLAGS: 00010206
RAX: 0000000000000082 RBX: 0000000000000000 RCX: ffff888160efda00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff89c3aca5 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5a4e0 R12: 0000000000000410
R13: dffffc0000000000 R14: ffffea0004450300 R15: 0000000004450300
FS:  00007f08f83e86c0(0000) GS:ffff88818d6fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd455a8fe8 CR3: 00000001134ac000 CR4: 00000000000006f0
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	00 00                	add    %al,(%rax)
   2:	89 c5                	mov    %eax,%ebp
   4:	31 ff                	xor    %edi,%edi
   6:	89 c6                	mov    %eax,%esi
   8:	e8 61 17 04 f8       	call   0xf804176e
   d:	85 ed                	test   %ebp,%ebp
   f:	0f 84 07 08 00 00    	je     0x81c
  15:	e8 54 12 04 f8       	call   0xf804126e
  1a:	49 81 c4 10 04 00 00 	add    $0x410,%r12
  21:	4c 89 e0             	mov    %r12,%rax
  24:	48 c1 e8 03          	shr    $0x3,%rax
* 28:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2d:	74 08                	je     0x37
  2f:	4c 89 e7             	mov    %r12,%rdi
  32:	e8 37 c7 73 f8       	call   0xf873c76e
  37:	4d 8b 24 24          	mov    (%r12),%r12
  3b:	4d 85 e4             	test   %r12,%r12


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
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