Description
In the Linux kernel, the following vulnerability has been resolved: ntb_netdev: Use dev_kfree_skb_any() in interrupt context TX/RX callback handlers (ntb_netdev_tx_handler(), ntb_netdev_rx_handler()) can be called in interrupt context via the DMA framework when the respective DMA operations have completed. As such, any calls by these routines to free skb's, should use the interrupt context safe dev_kfree_skb_any() function. Previously, these callback handlers would call the interrupt unsafe version of dev_kfree_skb(). This has not presented an issue on Intel IOAT DMA engines as that driver utilizes tasklets rather than a hard interrupt handler, like the AMD PTDMA DMA driver. On AMD systems, a kernel WARNING message is encountered, which is being issued from skb_release_head_state() due to in_hardirq() being true. Besides the user visible WARNING from the kernel, the other symptom of this bug was that TCP/IP performance across the ntb_netdev interface was very poor, i.e. approximately an order of magnitude below what was expected. With the repair to use dev_kfree_skb_any(), kernel WARNINGs from skb_release_head_state() ceased and TCP/IP performance, as measured by iperf, was on par with expected results, approximately 20 Gb/s on AMD Milan based server. Note that this performance is comparable with Intel based servers.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
548c237c0a9972df5d1afaca38aa733ee577128d to < d4460c82177899751975180c268f352893302221affected548c237c0a9972df5d1afaca38aa733ee577128d to < dd860b39aa7c7b82e6c99b6fdb99d4610ce49d67affected548c237c0a9972df5d1afaca38aa733ee577128d to < 8b78493968ed3cef0326183ed059c55e42f24d5baffected548c237c0a9972df5d1afaca38aa733ee577128d to < a6b9e09403102bdf8402dae734800e4916c7ea58affected548c237c0a9972df5d1afaca38aa733ee577128d to < 13286ad1c7c49c606fdcba4cf66f953a1a16c1caaffected548c237c0a9972df5d1afaca38aa733ee577128d to < 21296a52caa6a6bad6debdfe40ad81d4f1a27e69affected548c237c0a9972df5d1afaca38aa733ee577128d to < 14d245da57a11e80277ab455aa9b6dcc5ed38a19affected548c237c0a9972df5d1afaca38aa733ee577128d to < 07e28a8f450217db679802ebd4de0915556ce846affected548c237c0a9972df5d1afaca38aa733ee577128d to < 5f7d78b2b12a9d561f48fa00bab29b40f4616dadaffected
Linux Linux
Default version status: affected
3.9affected0 to < 3.9unaffected4.9.337 to ≤ 4.9.*unaffected4.14.303 to ≤ 4.14.*unaffected4.19.270 to ≤ 4.19.*unaffected5.4.229 to ≤ 5.4.*unaffected5.10.163 to ≤ 5.10.*unaffected5.15.86 to ≤ 5.15.*unaffected6.0.16 to ≤ 6.0.*unaffected6.1.2 to ≤ 6.1.*unaffected6.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/d4460c82177899751975180c268f352893302221 ↗
- https://git.kernel.org/stable/c/dd860b39aa7c7b82e6c99b6fdb99d4610ce49d67 ↗
- https://git.kernel.org/stable/c/8b78493968ed3cef0326183ed059c55e42f24d5b ↗
- https://git.kernel.org/stable/c/a6b9e09403102bdf8402dae734800e4916c7ea58 ↗
- https://git.kernel.org/stable/c/13286ad1c7c49c606fdcba4cf66f953a1a16c1ca ↗
- https://git.kernel.org/stable/c/21296a52caa6a6bad6debdfe40ad81d4f1a27e69 ↗
- https://git.kernel.org/stable/c/14d245da57a11e80277ab455aa9b6dcc5ed38a19 ↗
- https://git.kernel.org/stable/c/07e28a8f450217db679802ebd4de0915556ce846 ↗
- https://git.kernel.org/stable/c/5f7d78b2b12a9d561f48fa00bab29b40f4616dad ↗