In the Linux kernel, the following vulnerability has been resolved:
virtio/vsock: Fix accept_queue memory leak
As the final stages of socket destruction may be delayed, it is possible that virtiotransportrecvlisten() will be called after the acceptqueue has been flushed, but before the SOCK_DONE flag has been set. As a result, sockets enqueued after the flush would remain unremoved, leading to a memory leak.
vsockrelease _vsockrelease lock virtiotransportrelease virtiotransportclose scheduledelayedwork(closework) skshutdown = SHUTDOWNMASK (!) flush acceptqueue release virtiotransportrecvpkt vsockfindboundsocket lock if flag(SOCKDONE) return virtiotransportrecvlisten child = vsockcreateconnected (!) vsockenqueueaccept(child) release closework lock virtiotransportdoclose setflag(SOCKDONE) virtiotransportremovesock vsockremovesock vsockremovebound release
Introduce a skshutdown check to disallow vsockenqueue_accept() during socket destruction.
unreferenced object 0xffff888109e3f800 (size 2040): comm "kworker/5:2", pid 371, jiffies 4294940105 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00 (..@............ backtrace (crc 9e5f4e84): [<ffffffff81418ff1>] kmemcacheallocnoprof+0x2c1/0x360 [<ffffffff81d27aa0>] skprotalloc+0x30/0x120 [<ffffffff81d2b54c>] skalloc+0x2c/0x4b0 [<ffffffff81fe049a>] _vsockcreate.constprop.0+0x2a/0x310 [<ffffffff81fe6d6c>] virtiotransportrecvpkt+0x4dc/0x9a0 [<ffffffff81fe745d>] vsockloopbackwork+0xfd/0x140 [<ffffffff810fc6ac>] processonework+0x20c/0x570 [<ffffffff810fce3f>] workerthread+0x1bf/0x3a0 [<ffffffff811070dd>] kthread+0xdd/0x110 [<ffffffff81044fdd>] retfromfork+0x2d/0x50 [<ffffffff8100785a>] retfromfork_asm+0x1a/0x30