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authorSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>2020-11-13 21:12:05 +0100
committerJakub Kicinski <kuba@kernel.org>2020-11-17 01:34:49 +0100
commitfc70f5bf5e525dde81565f0a30d5e39168062eba (patch)
treee8e75cd3c40aac3b4aaaa1783656942338890ed0
parentnet: mvneta: fix possible memory leak in mvneta_swbm_add_rx_fragment (diff)
downloadlinux-fc70f5bf5e525dde81565f0a30d5e39168062eba.tar.xz
linux-fc70f5bf5e525dde81565f0a30d5e39168062eba.zip
net: qualcomm: rmnet: Fix incorrect receive packet handling during cleanup
During rmnet unregistration, the real device rx_handler is first cleared followed by the removal of rx_handler_data after the rcu synchronization. Any packets in the receive path may observe that the rx_handler is NULL. However, there is no check when dereferencing this value to use the rmnet_port information. This fixes following splat by adding the NULL check. Unable to handle kernel NULL pointer dereference at virtual address 000000000000000d pc : rmnet_rx_handler+0x124/0x284 lr : rmnet_rx_handler+0x124/0x284 rmnet_rx_handler+0x124/0x284 __netif_receive_skb_core+0x758/0xd74 __netif_receive_skb+0x50/0x17c process_backlog+0x15c/0x1b8 napi_poll+0x88/0x284 net_rx_action+0xbc/0x23c __do_softirq+0x20c/0x48c Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Sean Tranchetti <stranche@codeaurora.org> Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Link: https://lore.kernel.org/r/1605298325-3705-1-git-send-email-subashab@codeaurora.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 29a7bfa2584d..3d7d3ab383f8 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -188,6 +188,11 @@ rx_handler_result_t rmnet_rx_handler(struct sk_buff **pskb)
dev = skb->dev;
port = rmnet_get_port_rcu(dev);
+ if (unlikely(!port)) {
+ atomic_long_inc(&skb->dev->rx_nohandler);
+ kfree_skb(skb);
+ goto done;
+ }
switch (port->rmnet_mode) {
case RMNET_EPMODE_VND: