dd649b4921
commit 15bc8966b6d3a5b9bfe4c9facfa02f2b69b1e5f0 upstream. When we are not connected to a channel, sending channel "switch" announcement doesn't make any sense. The BSS list is empty in that case. This causes the for loop in cfg80211_get_bss() to be bypassed, so the function returns NULL (check line 1424 of net/wireless/scan.c), causing the WARN_ON() in ieee80211_ibss_csa_beacon() to get triggered (check line 500 of net/mac80211/ibss.c), which was consequently reported on the syzkaller dashboard. Thus, check if we have an existing connection before generating the CSA beacon in ieee80211_ibss_finish_csa(). Cc: stable@vger.kernel.org Fixes: cd7760e62c2a ("mac80211: add support for CSA in IBSS mode") Link: https://syzkaller.appspot.com/bug?id=05603ef4ae8926761b678d2939a3b2ad28ab9ca6 Reported-by: syzbot+b6c9fe29aefe68e4ad34@syzkaller.appspotmail.com Signed-off-by: Siddh Raman Pant <code@siddh.me> Tested-by: syzbot+b6c9fe29aefe68e4ad34@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20220814151512.9985-1-code@siddh.me Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.