general protection fault in rxrpc_kernel_recv_data

Status: upstream: reported on 2026/08/29 02:56
Reported-by: syzbot+ad230ef43e8fff30e474@syzkaller.appspotmail.com
First crash: 1d15h, last: 1d12h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in rxrpc_kernel_recv_data 19 1 9d18h 9d18h 0/3 upstream: reported on 2026/08/20 23:42

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc000000006f: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000378-0x000000000000037f]
CPU: 0 PID: 6260 Comm: kworker/0:12 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: kafsd afs_process_async_call
RIP: 0010:rxrpc_kernel_recv_data+0x5f/0x510 net/rxrpc/recvmsg.c:710
Code: 28 48 bd 00 00 00 00 00 fc ff df e8 9b 1b 72 f8 48 c7 44 24 20 00 00 00 00 4c 8d bb 78 03 00 00 4d 89 fc 49 c1 ec 03 49 89 ee <41> 0f b6 04 2c 84 c0 0f 85 62 03 00 00 41 8b 2f bf 06 00 00 00 89
RSP: 0000:ffffc9000348f9b0 EFLAGS: 00010206
RAX: ffffffff8906f405 RBX: 0000000000000000 RCX: ffff88802a5b5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888074712a00
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffc9000348fa60
R10: dffffc0000000000 R11: ffffed100b1f9627 R12: 000000000000006f
R13: ffff888058fcb120 R14: dffffc0000000000 R15: 0000000000000378
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3290fff8 CR3: 000000002b3a0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 afs_extract_data+0x134/0x650 fs/afs/rxrpc.c:906
 afs_deliver_vl_get_capabilities+0x127/0x300 fs/afs/vlclient.c:329
 afs_deliver_to_call+0x12b/0x1100 fs/afs/rxrpc.c:510
 afs_process_async_call+0x7e/0xe0 fs/afs/rxrpc.c:702
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Modules linked in:
---[ end trace 7c0ff868a4807332 ]---
RIP: 0010:rxrpc_kernel_recv_data+0x5f/0x510 net/rxrpc/recvmsg.c:710
Code: 28 48 bd 00 00 00 00 00 fc ff df e8 9b 1b 72 f8 48 c7 44 24 20 00 00 00 00 4c 8d bb 78 03 00 00 4d 89 fc 49 c1 ec 03 49 89 ee <41> 0f b6 04 2c 84 c0 0f 85 62 03 00 00 41 8b 2f bf 06 00 00 00 89
RSP: 0000:ffffc9000348f9b0 EFLAGS: 00010206
RAX: ffffffff8906f405 RBX: 0000000000000000 RCX: ffff88802a5b5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888074712a00
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffc9000348fa60
R10: dffffc0000000000 R11: ffffed100b1f9627 R12: 000000000000006f
R13: ffff888058fcb120 R14: dffffc0000000000 R15: 0000000000000378
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd21ec9dc0 CR3: 00000000247f6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	28 48 bd             	sub    %cl,-0x43(%rax)
   3:	00 00                	add    %al,(%rax)
   5:	00 00                	add    %al,(%rax)
   7:	00 fc                	add    %bh,%ah
   9:	ff                   	lcall  (bad)
   a:	df e8                	fucomip %st(0),%st
   c:	9b                   	fwait
   d:	1b 72 f8             	sbb    -0x8(%rdx),%esi
  10:	48 c7 44 24 20 00 00 	movq   $0x0,0x20(%rsp)
  17:	00 00
  19:	4c 8d bb 78 03 00 00 	lea    0x378(%rbx),%r15
  20:	4d 89 fc             	mov    %r15,%r12
  23:	49 c1 ec 03          	shr    $0x3,%r12
  27:	49 89 ee             	mov    %rbp,%r14
* 2a:	41 0f b6 04 2c       	movzbl (%r12,%rbp,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 62 03 00 00    	jne    0x399
  37:	41 8b 2f             	mov    (%r15),%ebp
  3a:	bf 06 00 00 00       	mov    $0x6,%edi
  3f:	89                   	.byte 0x89

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/29 05:37 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in rxrpc_kernel_recv_data
2026/08/29 05:25 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in rxrpc_kernel_recv_data
2026/08/29 02:55 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in rxrpc_kernel_recv_data
2026/08/29 05:28 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in rxrpc_kernel_recv_data
* Struck through repros no longer work on HEAD.