[ Upstream commit de1887c064b9996ac03120d90d0a909a3f678f98 ]
We don't check for the validity of the lengths in the packet received from the firmware. If the MPDU length received in the rx descriptor is too short to contain the header length and the crypt length together, we may end up trying to copy a negative number of bytes (headlen - hdrlen < 0) which will underflow and cause us to try to copy a huge amount of data. This causes oopses such as this one:
BUG: unable to handle kernel paging request at ffff896be2970000 PGD 5e201067 P4D 5e201067 PUD 5e205067 PMD 16110d063 PTE 8000000162970161 Oops: 0003 [#1] PREEMPT SMP NOPTI CPU: 2 PID: 1824 Comm: irq/134-iwlwifi Not tainted 4.19.33-04308-geea41cf4930f #1 Hardware name: [...] RIP: 0010:memcpy_erms+0x6/0x10 Code: 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe RSP: 0018:ffffa4630196fc60 EFLAGS: 00010287 RAX: ffff896be2924618 RBX: ffff896bc8ecc600 RCX: 00000000fffb4610 RDX: 00000000fffffff8 RSI: ffff896a835e2a38 RDI: ffff896be2970000 RBP: ffffa4630196fd30 R08: ffff896bc8ecc600 R09: ffff896a83597000 R10: ffff896bd6998400 R11: 000000000200407f R12: ffff896a83597050 R13: 00000000fffffff8 R14: 0000000000000010 R15: ffff896a83597038 FS: 0000000000000000(0000) GS:ffff896be8280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff896be2970000 CR3: 000000005dc12002 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: iwl_mvm_rx_mpdu_mq+0xb51/0x121b [iwlmvm] iwl_pcie_rx_handle+0x58c/0xa89 [iwlwifi] iwl_pcie_irq_rx_msix_handler+0xd9/0x12a [iwlwifi] irq_thread_fn+0x24/0x49 irq_thread+0xb0/0x122 kthread+0x138/0x140 ret_from_fork+0x1f/0x40
Fix that by checking the lengths for correctness and trigger a warning to show that we have received wrong data.
Signed-off-by: Luca Coelho luciano.coelho@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 28 ++++++++++++++++--- 1 file changed, 24 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c index 7bd8676508f54..519c7dd47f694 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c @@ -143,9 +143,9 @@ static inline int iwl_mvm_check_pn(struct iwl_mvm *mvm, struct sk_buff *skb, }
/* iwl_mvm_create_skb Adds the rxb to a new skb */ -static void iwl_mvm_create_skb(struct sk_buff *skb, struct ieee80211_hdr *hdr, - u16 len, u8 crypt_len, - struct iwl_rx_cmd_buffer *rxb) +static int iwl_mvm_create_skb(struct iwl_mvm *mvm, struct sk_buff *skb, + struct ieee80211_hdr *hdr, u16 len, u8 crypt_len, + struct iwl_rx_cmd_buffer *rxb) { struct iwl_rx_packet *pkt = rxb_addr(rxb); struct iwl_rx_mpdu_desc *desc = (void *)pkt->data; @@ -178,6 +178,20 @@ static void iwl_mvm_create_skb(struct sk_buff *skb, struct ieee80211_hdr *hdr, * present before copying packet data. */ hdrlen += crypt_len; + + if (WARN_ONCE(headlen < hdrlen, + "invalid packet lengths (hdrlen=%d, len=%d, crypt_len=%d)\n", + hdrlen, len, crypt_len)) { + /* + * We warn and trace because we want to be able to see + * it in trace-cmd as well. + */ + IWL_DEBUG_RX(mvm, + "invalid packet lengths (hdrlen=%d, len=%d, crypt_len=%d)\n", + hdrlen, len, crypt_len); + return -EINVAL; + } + skb_put_data(skb, hdr, hdrlen); skb_put_data(skb, (u8 *)hdr + hdrlen + pad_len, headlen - hdrlen);
@@ -190,6 +204,8 @@ static void iwl_mvm_create_skb(struct sk_buff *skb, struct ieee80211_hdr *hdr, skb_add_rx_frag(skb, 0, rxb_steal_page(rxb), offset, fraglen, rxb->truesize); } + + return 0; }
/* iwl_mvm_pass_packet_to_mac80211 - passes the packet for mac80211 */ @@ -1600,7 +1616,11 @@ void iwl_mvm_rx_mpdu_mq(struct iwl_mvm *mvm, struct napi_struct *napi, rx_status->boottime_ns = ktime_get_boot_ns(); }
- iwl_mvm_create_skb(skb, hdr, len, crypt_len, rxb); + if (iwl_mvm_create_skb(mvm, skb, hdr, len, crypt_len, rxb)) { + kfree_skb(skb); + goto out; + } + if (!iwl_mvm_reorder(mvm, napi, queue, sta, skb, desc)) iwl_mvm_pass_packet_to_mac80211(mvm, napi, skb, queue, sta); out: