CVE-2024-43835

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> virtio_net: Fix napi_skb_cache_put warning<br /> <br /> After the commit bdacf3e34945 ("net: Use nested-BH locking for<br /> napi_alloc_cache.") was merged, the following warning began to appear:<br /> <br /> WARNING: CPU: 5 PID: 1 at net/core/skbuff.c:1451 napi_skb_cache_put+0x82/0x4b0<br /> <br /> __warn+0x12f/0x340<br /> napi_skb_cache_put+0x82/0x4b0<br /> napi_skb_cache_put+0x82/0x4b0<br /> report_bug+0x165/0x370<br /> handle_bug+0x3d/0x80<br /> exc_invalid_op+0x1a/0x50<br /> asm_exc_invalid_op+0x1a/0x20<br /> __free_old_xmit+0x1c8/0x510<br /> napi_skb_cache_put+0x82/0x4b0<br /> __free_old_xmit+0x1c8/0x510<br /> __free_old_xmit+0x1c8/0x510<br /> __pfx___free_old_xmit+0x10/0x10<br /> <br /> The issue arises because virtio is assuming it&amp;#39;s running in NAPI context<br /> even when it&amp;#39;s not, such as in the netpoll case.<br /> <br /> To resolve this, modify virtnet_poll_tx() to only set NAPI when budget<br /> is available. Same for virtnet_poll_cleantx(), which always assumed that<br /> it was in a NAPI context.