From: Nick Child nnac123@linux.ibm.com
mainline inclusion from mainline-v6.10-rc6 commit 0983d288caf984de0202c66641577b739caad561 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEMC CVE: CVE-2024-41066
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Below is a summary of how the driver stores a reference to an skb during transmit: tx_buff[free_map[consumer_index]]->skb = new_skb; free_map[consumer_index] = IBMVNIC_INVALID_MAP; consumer_index ++; Where variable data looks like this: free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3] consumer_index^ tx_buff == [skb=null, skb=<ptr>, skb=<ptr>, skb=null, skb=null]
The driver has checks to ensure that free_map[consumer_index] pointed to a valid index but there was no check to ensure that this index pointed to an unused/null skb address. So, if, by some chance, our free_map and tx_buff lists become out of sync then we were previously risking an skb memory leak. This could then cause tcp congestion control to stop sending packets, eventually leading to ETIMEDOUT.
Therefore, add a conditional to ensure that the skb address is null. If not then warn the user (because this is still a bug that should be patched) and free the old pointer to prevent memleak/tcp problems.
Signed-off-by: Nick Child nnac123@linux.ibm.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Dong Chenchen dongchenchen2@huawei.com --- drivers/net/ethernet/ibm/ibmvnic.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index ca21e55335b2..61685c3053ad 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2478,6 +2478,18 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) (tx_pool->consumer_index + 1) % tx_pool->num_buffers;
tx_buff = &tx_pool->tx_buff[bufidx]; + + /* Sanity checks on our free map to make sure it points to an index + * that is not being occupied by another skb. If skb memory is + * not freed then we see congestion control kick in and halt tx. + */ + if (unlikely(tx_buff->skb)) { + dev_warn_ratelimited(dev, "TX free map points to untracked skb (%s %d idx=%d)\n", + skb_is_gso(skb) ? "tso_pool" : "tx_pool", + queue_num, bufidx); + dev_kfree_skb_any(tx_buff->skb); + } + tx_buff->skb = skb; tx_buff->index = bufidx; tx_buff->pool_index = queue_num;
反馈: 您发送到kernel@openeuler.org的补丁/补丁集,转换为PR失败! 邮件列表地址:https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/V... 失败原因:应用补丁/补丁集失败,Patch failed at 0001 ibmvnic: Add tx check to prevent skb leak 建议解决方法:请查看失败原因, 确认补丁是否可以应用在当前期望分支的最新代码上
FeedBack: The patch(es) which you have sent to kernel@openeuler.org has been converted to PR failed! Mailing list address: https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/V... Failed Reason: apply patch(es) failed, Patch failed at 0001 ibmvnic: Add tx check to prevent skb leak Suggest Solution: please checkout if the failed patch(es) can work on the newest codes in expected branch