[BUG] rtlwifi: a crash in error handling code of rtl_pci_probe()

[Jia-Ju Bai]

In rtl_pci_probe(), when request_irq() in rtl_pci_intr_mode_legacy() in 
rtl_pci_intr_mode_decide() fails, a crash occurs.
The crash information is as follows:

[  108.271155] kasan: CONFIG_KASAN_INLINE enabled
[  108.271163] kasan: GPF could be caused by NULL-ptr deref or user 
memory access
......
[  108.271193] RIP: 0010:cfg80211_get_drvinfo+0xce/0x3b0 [cfg80211]
......
[  108.271235] Call Trace:
[  108.271245]  ethtool_get_drvinfo+0x110/0x640
[  108.271255]  ? cfg80211_get_chan_state+0x7e0/0x7e0 [cfg80211]
[  108.271261]  ? ethtool_get_settings+0x340/0x340
[  108.271268]  ? __read_once_size_nocheck.constprop.7+0x20/0x20
[  108.271279]  ? kasan_check_write+0x14/0x20
[  108.271284]  dev_ethtool+0x272d/0x4c20
[  108.271290]  ? unwind_get_return_address+0x66/0xb0
[  108.271299]  ? __save_stack_trace+0x92/0x100
[  108.271307]  ? ethtool_get_rxnfc+0x3f0/0x3f0
[  108.271316]  ? save_stack+0xa3/0xd0
[  108.271323]  ? save_stack+0x43/0xd0
[  108.271331]  ? ftrace_graph_ret_addr+0x2d/0x170
[  108.271338]  ? ftrace_graph_ret_addr+0x2d/0x170
[  108.271346]  ? ftrace_graph_ret_addr+0x2d/0x170
[  108.271354]  ? update_stack_state+0x3b2/0x670
[  108.271361]  ? update_stack_state+0x3b2/0x670
[  108.271370]  ? __read_once_size_nocheck.constprop.7+0x20/0x20
[  108.271379]  ? unwind_next_frame.part.5+0x19f/0xa60
[  108.271388]  ? bpf_prog_kallsyms_find+0x3e/0x270
[  108.271396]  ? is_bpf_text_address+0x1a/0x30
[  108.271408]  ? kernel_text_address+0x11d/0x130
[  108.271416]  ? __kernel_text_address+0x12/0x40
[  108.271423]  ? unwind_get_return_address+0x66/0xb0
[  108.271431]  ? __save_stack_trace+0x92/0x100
[  108.271440]  ? save_stack+0xa3/0xd0
[  108.271448]  ? udp_ioctl+0x35/0xe0
[  108.271457]  ? inet_ioctl+0x100/0x320
[  108.271466]  ? inet_stream_connect+0xb0/0xb0
[  108.271475]  ? alloc_file+0x60/0x480
[  108.271483]  ? alloc_file_pseudo+0x19d/0x270
[  108.271495]  ? sock_alloc_file+0x51/0x170
[  108.271502]  ? __sys_socket+0x12c/0x1f0
[  108.271510]  ? __x64_sys_socket+0x78/0xb0
[  108.271520]  ? do_syscall_64+0xb1/0x2e0
[  108.271529]  ? entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  108.271538]  ? kasan_check_read+0x11/0x20
[  108.271548]  ? mutex_lock+0x8f/0xe0
[  108.271557]  ? __mutex_lock_slowpath+0x20/0x20
[  108.271568]  dev_ioctl+0x1fb/0xae0
[  108.271576]  ? dev_ioctl+0x1fb/0xae0
[  108.271586]  ? _copy_from_user+0x71/0xd0
[  108.271594]  sock_do_ioctl+0x1e2/0x2f0
[  108.271602]  ? kmem_cache_alloc+0xf9/0x250
[  108.271611]  ? ___sys_recvmsg+0x5a0/0x5a0
[  108.271621]  ? apparmor_file_alloc_security+0x128/0x7e0
[  108.271630]  ? kasan_unpoison_shadow+0x35/0x50
[  108.271638]  ? kasan_kmalloc+0xad/0xe0
[  108.271652]  ? apparmor_file_alloc_security+0x128/0x7e0
[  108.271662]  ? apparmor_file_alloc_security+0x269/0x7e0
[  108.271670]  sock_ioctl+0x361/0x590
[  108.271678]  ? sock_ioctl+0x361/0x590
[  108.271686]  ? routing_ioctl+0x470/0x470
[  108.271695]  ? kasan_check_write+0x14/0x20
[  108.271703]  ? __mutex_init+0xba/0x130
[  108.271713]  ? percpu_counter_add_batch+0xc7/0x120
[  108.271722]  ? alloc_empty_file+0xae/0x150
[  108.271729]  ? routing_ioctl+0x470/0x470
[  108.271738]  do_vfs_ioctl+0x1ae/0xfe0
[  108.271745]  ? do_vfs_ioctl+0x1ae/0xfe0
[  108.271754]  ? alloc_file_pseudo+0x1ad/0x270
[  108.271762]  ? ioctl_preallocate+0x1e0/0x1e0
[  108.271770]  ? alloc_file+0x480/0x480
[  108.271778]  ? kasan_check_read+0x11/0x20
[  108.271786]  ? __fget+0x24d/0x320
[  108.271794]  ? iterate_fd+0x180/0x180
[  108.271802]  ? fd_install+0x52/0x60
[  108.271812]  ? security_file_ioctl+0x8c/0xb0
[  108.271820]  ksys_ioctl+0x99/0xb0
[  108.271829]  __x64_sys_ioctl+0x78/0xb0
[  108.271839]  do_syscall_64+0xb1/0x2e0
[  108.271857]  ? prepare_exit_to_usermode+0xc8/0x160
[  108.271871]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
......

I checked the driver source code, but cannot find the reason, so I only 
report the crash...
Can somebody give an explanation about this crash?

This crash is triggered by a runtime fuzzing tool named FIZZER written 
by us.


Best wishes,
Jia-Ju Bai