| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-41066: ibmvnic: Add tx check to prevent skb leak |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ibmvnic: Add tx check to prevent skb leak |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2024-41066 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 6.1.101 with commit 16ad1557cae582e79bb82dddd612d9bdfaa11d4c |
| Fixed in 6.6.42 with commit 267c61c4afed0ff9a2e83462abad3f41d8ca1f06 |
| Fixed in 6.9.11 with commit e7b75def33eae61ddaad6cb616c517dc3882eb2a |
| Fixed in 6.10 with commit 0983d288caf984de0202c66641577b739caad561 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-41066 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/net/ethernet/ibm/ibmvnic.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/16ad1557cae582e79bb82dddd612d9bdfaa11d4c |
| https://git.kernel.org/stable/c/267c61c4afed0ff9a2e83462abad3f41d8ca1f06 |
| https://git.kernel.org/stable/c/e7b75def33eae61ddaad6cb616c517dc3882eb2a |
| https://git.kernel.org/stable/c/0983d288caf984de0202c66641577b739caad561 |
