BUG: using smp_processor_id() in preemptible code in radix_tree_node_alloc

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    acf25aa6 Merge tag 'Smack-for-5.8' of git://github.com/csc..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13d6307a100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5263d9b5bce03c67
dashboard link: https://syzkaller.appspot.com/bug?extid=3eec59e770685e3dc879
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15bd4c1e100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1520c9de100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3eec59e770685e3dc879@xxxxxxxxxxxxxxxxxxxxxxxxx

RAX: ffffffffffffffda RBX: 00007ffdf01d56d0 RCX: 00000000004406c9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 0000000000000005 R08: 0000000000000001 R09: 0000000000000031
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401f50
R13: 0000000000401fe0 R14: 0000000000000000 R15: 0000000000000000
BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor036/6796
caller is radix_tree_node_alloc.constprop.0+0x200/0x330 lib/radix-tree.c:262
CPU: 0 PID: 6796 Comm: syz-executor036 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 check_preemption_disabled lib/smp_processor_id.c:47 [inline]
 debug_smp_processor_id.cold+0x88/0x9b lib/smp_processor_id.c:57
 radix_tree_node_alloc.constprop.0+0x200/0x330 lib/radix-tree.c:262
 radix_tree_extend+0x256/0x4e0 lib/radix-tree.c:424
 idr_get_free+0x60c/0x8e0 lib/radix-tree.c:1492
 idr_alloc_u32+0x170/0x2d0 lib/idr.c:46
 idr_alloc+0xc2/0x130 lib/idr.c:87
 qrtr_port_assign net/qrtr/qrtr.c:703 [inline]
 __qrtr_bind.isra.0+0x12e/0x5c0 net/qrtr/qrtr.c:756
 qrtr_autobind net/qrtr/qrtr.c:787 [inline]
 qrtr_autobind+0xaf/0xf0 net/qrtr/qrtr.c:775
 qrtr_sendmsg+0x1d6/0x770 net/qrtr/qrtr.c:895
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e6/0x810 net/socket.c:2352
 ___sys_sendmsg+0x100/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x4406c9
Code: 25 02 00 85 c0 b8 00 00 00 00 48 0f 44 c3 5b c3 90 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdf01d56c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffdf01d56d0 RCX: 00000000004406c9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 0000000000000005 R08: 0000000000000001 R09: 0000000000000031
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401f50
R13: 0000000000401fe0 R14: 0000000000000000 R15: 0000000000000000


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