From 75239f276ec894c87b8fbc268bdfb0f9fd290445 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 7 Feb 2017 08:07:39 +0100 Subject: backports: get rid of patch directory structure This directory structure was never really managed well, simply get rid of it. With the patch system that only applies patches when the modified file exists, and with a lot of spatches applying everywhere anyway, it's no longer really useful either. Signed-off-by: Johannes Berg --- patches/0003-cfg80211-wext-padding/INFO | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 patches/0003-cfg80211-wext-padding/INFO (limited to 'patches/0003-cfg80211-wext-padding/INFO') diff --git a/patches/0003-cfg80211-wext-padding/INFO b/patches/0003-cfg80211-wext-padding/INFO new file mode 100644 index 00000000..3d0044da --- /dev/null +++ b/patches/0003-cfg80211-wext-padding/INFO @@ -0,0 +1,30 @@ +This is a tricky one. + +Consider a kernel that has this code in net/wireless/wext-core.c: + +#ifdef CONFIG_CFG80211_WEXT + if (dev->ieee80211_ptr && dev->ieee80211_ptr->wiphy) + handlers = dev->ieee80211_ptr->wiphy->wext; +#endif +#ifdef CONFIG_WIRELESS_EXT + if (dev->wireless_handlers) + handlers = dev->wireless_handlers; +#endif + +If a kernel is compiled without CONFIG_WIRELESS_EXT then +compat-drivers can't do wireless extensions against it. +However, if the kernel is compiled with CONFIG_CFG80211_WEXT +then it will try to get the wext handlers from struct wiphy. + +Now, struct wiphy in the base kernel and struct wiphy in +compat-drivers don't match, so the kernel crashes!! + +To fix this, add lots of padding to compat-drivers's +struct wiphy so that the "wext" pointer is guaranteed +to be NULL. + +Make sure the padding is larger than the struct so we +don't ever run into this again because the wext pointer +moved due to struct enlargements. + + -- cgit v1.2.3