From 4f031fa9f188b2b0641ac20087d9e16bcfb4e49d Mon Sep 17 00:00:00 2001 From: Ronald Wahl Date: Thu, 6 Nov 2014 11:52:13 +0100 Subject: [PATCH] mac80211: Fix regression that triggers a kernel BUG with CCMP Commit 7ec7c4a9a686c608315739ab6a2b0527a240883c (mac80211: port CCMP to cryptoapi's CCM driver) introduced a regression when decrypting empty packets (data_len == 0). This will lead to backtraces like: (scatterwalk_start) from [] (scatterwalk_map_and_copy+0x2c/0xa8) (scatterwalk_map_and_copy) from [] (crypto_ccm_decrypt+0x7c/0x25c) (crypto_ccm_decrypt) from [] (ieee80211_aes_ccm_decrypt+0x160/0x170) (ieee80211_aes_ccm_decrypt) from [] (ieee80211_crypto_ccmp_decrypt+0x1ac/0x238) (ieee80211_crypto_ccmp_decrypt) from [] (ieee80211_rx_handlers+0x870/0x1d24) (ieee80211_rx_handlers) from [] (ieee80211_prepare_and_rx_handle+0x8a0/0x91c) (ieee80211_prepare_and_rx_handle) from [] (ieee80211_rx+0x568/0x730) (ieee80211_rx) from [] (__carl9170_rx+0x94c/0xa20) (__carl9170_rx) from [] (carl9170_rx_stream+0x1fc/0x320) (carl9170_rx_stream) from [] (carl9170_usb_tasklet+0x80/0xc8) (carl9170_usb_tasklet) from [] (tasklet_hi_action+0x88/0xcc) (tasklet_hi_action) from [] (__do_softirq+0xcc/0x200) (__do_softirq) from [] (irq_exit+0x80/0xe0) (irq_exit) from [] (handle_IRQ+0x64/0x80) (handle_IRQ) from [] (__irq_svc+0x40/0x4c) (__irq_svc) from [] (arch_cpu_idle+0x2c/0x34) Such packets can appear for example when using the carl9170 wireless driver because hardware sometimes generates garbage when the internal FIFO overruns. This patch adds an additional length check. Cc: stable@vger.kernel.org Fixes: 7ec7c4a9a686 ("mac80211: port CCMP to cryptoapi's CCM driver") Acked-by: Ard Biesheuvel Signed-off-by: Ronald Wahl Signed-off-by: Johannes Berg --- net/mac80211/aes_ccm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c index ec24378caaaf..09d9caaec591 100644 --- a/net/mac80211/aes_ccm.c +++ b/net/mac80211/aes_ccm.c @@ -53,6 +53,9 @@ int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, __aligned(__alignof__(struct aead_request)); struct aead_request *aead_req = (void *) aead_req_data; + if (data_len == 0) + return -EINVAL; + memset(aead_req, 0, sizeof(aead_req_data)); sg_init_one(&pt, data, data_len); -- 2.20.1