https://github.com/torvalds/linux
Revision 788211d81bfdf9b6a547d0530f206ba6ee76b107 authored by Johannes Berg on 01 April 2015, 12:20:42 UTC, committed by Johannes Berg on 01 April 2015, 12:35:01 UTC
There's an issue with the way the RX A-MPDU reorder timer is deleted that can cause a kernel crash like this: * tid_rx is removed - call_rcu(ieee80211_free_tid_rx) * station is destroyed * reorder timer fires before ieee80211_free_tid_rx() runs, accessing the station, thus potentially crashing due to the use-after-free The station deletion is protected by synchronize_net(), but that isn't enough -- ieee80211_free_tid_rx() need not have run when that returns (it deletes the timer.) We could use rcu_barrier() instead of synchronize_net(), but that's much more expensive. Instead, to fix this, add a field tracking that the session is being deleted. In this case, the only re-arming of the timer happens with the reorder spinlock held, so make that code not rearm it if the session is being deleted and also delete the timer after setting that field. This ensures the timer cannot fire after ___ieee80211_stop_rx_ba_session() returns, which fixes the problem. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg <johannes.berg@intel.com>
1 parent f84eaa1
Tip revision: 788211d81bfdf9b6a547d0530f206ba6ee76b107 authored by Johannes Berg on 01 April 2015, 12:20:42 UTC
mac80211: fix RX A-MPDU session reorder timer deletion
mac80211: fix RX A-MPDU session reorder timer deletion
Tip revision: 788211d
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .gitignore | -rw-r--r-- | 1.2 KB |
| .mailmap | -rw-r--r-- | 4.9 KB |
| COPYING | -rw-r--r-- | 18.3 KB |
| CREDITS | -rw-r--r-- | 94.0 KB |
| Kbuild | -rw-r--r-- | 2.5 KB |
| Kconfig | -rw-r--r-- | 252 bytes |
| MAINTAINERS | -rw-r--r-- | 297.9 KB |
| Makefile | -rw-r--r-- | 53.3 KB |
| README | -rw-r--r-- | 18.3 KB |
| REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
Computing file changes ...
