1.6 KiB
CVE-2024-43835
Description
In the Linux kernel, the following vulnerability has been resolved:virtio_net: Fix napi_skb_cache_put warningAfter the commit bdacf3e34945 ("net: Use nested-BH locking fornapi_alloc_cache.") was merged, the following warning began to appear: WARNING: CPU: 5 PID: 1 at net/core/skbuff.c:1451 napi_skb_cache_put+0x82/0x4b0 __warn+0x12f/0x340 napi_skb_cache_put+0x82/0x4b0 napi_skb_cache_put+0x82/0x4b0 report_bug+0x165/0x370 handle_bug+0x3d/0x80 exc_invalid_op+0x1a/0x50 asm_exc_invalid_op+0x1a/0x20 __free_old_xmit+0x1c8/0x510 napi_skb_cache_put+0x82/0x4b0 __free_old_xmit+0x1c8/0x510 __free_old_xmit+0x1c8/0x510 __pfx___free_old_xmit+0x10/0x10The issue arises because virtio is assuming it's running in NAPI contexteven when it's not, such as in the netpoll case.To resolve this, modify virtnet_poll_tx() to only set NAPI when budgetis available. Same for virtnet_poll_cleantx(), which always assumed thatit was in a NAPI context.
POC
Reference
No PoCs from references.