Subject: [syzbot] [bpf?] [net?] general protection fault in __cpu_map_flush

From: syzbot <[email-masked]>
Date: Thu, 18 Jul 2024 14:31:25 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    b1bc554e009e Merge tag 'media/v6.11-1' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=165f372d980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=65e004fdd6e65e46
dashboard link: https://syzkaller.appspot.com/bug?extid=c226757eb784a9da3e8b
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eba440b3a1dc/disk-b1bc554e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7ef97684b39f/vmlinux-b1bc554e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c465a94c9348/bzImage-b1bc554e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

Oops: general protection fault, probably for non-canonical address 0xe3fffb240028e7c8: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: maybe wild-memory-access in range [0x1ffff92001473e40-0x1ffff92001473e47]
CPU: 0 PID: 5818 Comm: syz.2.162 Not tainted 6.10.0-syzkaller-05505-gb1bc554e009e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:__cpu_map_flush+0x42/0xd0
Code: e8 e3 d9 d6 ff 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 8d c7 39 00 49 8b 1e 4c 39 f3 74 77 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 6f c7 39 00 4c 8b 23 48 8d 7b c0
RSP: 0018:ffffc90000007bb0 EFLAGS: 00010203
RAX: 03ffff240028e7c8 RBX: 1ffff92001473e44 RCX: ffff888027121e00
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffffc9000a39f1a0
RBP: dffffc0000000000 R08: ffffffff895d4e8a R09: 1ffffffff1f5a8c5
R10: dffffc0000000000 R11: fffffbfff1f5a8c6 R12: ffffc9000a39f1a0
R13: ffffc9000a39f160 R14: ffffc9000a39f1a0 R15: dffffc0000000000
FS:  00007feb6f7916c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c343cd0 CR3: 000000001ec24000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 xdp_do_check_flushed+0x136/0x240 net/core/filter.c:4304
 __napi_poll+0xe4/0x490 net/core/dev.c:6774
 napi_poll net/core/dev.c:6840 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:6962
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 tun_rx_batched+0x732/0x8f0
 tun_get_user+0x2f84/0x4720 drivers/net/tun.c:2006
 tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2052
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb6e9746df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 8c 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 8c 02 00 48
RSP: 002b:00007feb6f791010 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feb6eb03f60 RCX: 00007feb6e9746df
RDX: 0000000000000036 RSI: 0000000020000240 RDI: 00000000000000c8
RBP: 00007feb6e9e4e5d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000036 R11: 0000000000000293 R12: 0000000000000000
R13: 000000000000000b R14: 00007feb6eb03f60 R15: 00007ffcc6c5e298
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__cpu_map_flush+0x42/0xd0
Code: e8 e3 d9 d6 ff 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 8d c7 39 00 49 8b 1e 4c 39 f3 74 77 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 6f c7 39 00 4c 8b 23 48 8d 7b c0
RSP: 0018:ffffc90000007bb0 EFLAGS: 00010203
RAX: 03ffff240028e7c8 RBX: 1ffff92001473e44 RCX: ffff888027121e00
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffffc9000a39f1a0
RBP: dffffc0000000000 R08: ffffffff895d4e8a R09: 1ffffffff1f5a8c5
R10: dffffc0000000000 R11: fffffbfff1f5a8c6 R12: ffffc9000a39f1a0
R13: ffffc9000a39f160 R14: ffffc9000a39f1a0 R15: dffffc0000000000
FS:  00007feb6f7916c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c343cd0 CR3: 000000001ec24000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 e3 d9 d6 ff       	call   0xffd6d9e8
   5:	4c 89 f0             	mov    %r14,%rax
   8:	48 c1 e8 03          	shr    $0x3,%rax
   c:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
  11:	74 08                	je     0x1b
  13:	4c 89 f7             	mov    %r14,%rdi
  16:	e8 8d c7 39 00       	call   0x39c7a8
  1b:	49 8b 1e             	mov    (%r14),%rbx
  1e:	4c 39 f3             	cmp    %r14,%rbx
  21:	74 77                	je     0x9a
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 6f c7 39 00       	call   0x39c7a8
  39:	4c 8b 23             	mov    (%rbx),%r12
  3c:	48 8d 7b c0          	lea    -0x40(%rbx),%rdi

---
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