mwifiex: don't call del_timer_sync() on uninitialized timer

syzbot is reporting that del_timer_sync() is called from
mwifiex_usb_cleanup_tx_aggr() from mwifiex_unregister_dev() without
checking timer_setup() from mwifiex_usb_tx_init() was called [1].

Ganapathi Bhat proposed a possibly cleaner fix, but it seems that
that fix was forgotten [2].

"grep -FrB1 'del_timer' drivers/ | grep -FA1 '.function)'" says that
currently there are 28 locations which call del_timer[_sync]() only if
that timer's function field was initialized (because timer_setup() sets
that timer's function field). Therefore, let's use same approach here.

[1] https://syzkaller.appspot.com/bug?id=26525f643f454dd7be0078423e3cdb0d57744959
[2] https://lkml.kernel.org/r/CA+ASDXMHt2gq9Hy+iP_BYkWXsSreWdp3_bAfMkNcuqJ3K+-jbQ@mail.gmail.com

Reported-by: syzbot <[email protected]>
Cc: Ganapathi Bhat <[email protected]>
Cc: Brian Norris <[email protected]>
Signed-off-by: Tetsuo Handa <[email protected]>
Reviewed-by: Brian Norris <[email protected]>
Acked-by: Ganapathi Bhat <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

0 files changed, 0 insertions, 0 deletions