"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slab_common: fix possible double free of kmem_cache\n\nWhen doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu'\nkunit test case cause a use-after-free error:\n\n BUG: KASAN: use-after-free in kobject_del+0x14/0x30\n Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261\n\n CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n Call Trace:\n <TASK>\n dump_stack_lvl+0x34/0x48\n print_address_description.constprop.0+0x87/0x2a5\n print_report+0x103/0x1ed\n kasan_report+0xb7/0x140\n kobject_del+0x14/0x30\n kmem_cache_destroy+0x130/0x170\n test_exit+0x1a/0x30\n kunit_try_run_case+0xad/0xc0\n kunit_generic_run_threadfn_adapter+0x26/0x50\n kthread+0x17b/0x1b0\n </TASK>\n\nThe cause is inside kmem_cache_destroy():\n\nkmem_cache_destroy\n acquire lock/mutex\n shutdown_cache\n schedule_work(kmem_cache_release) (if RCU flag set)\n release lock/mutex\n kmem_cache_release (if RCU flag not set)\n\nIn some certain timing, the scheduled work could be run before\nthe next RCU flag checking, which can then get a wrong value\nand lead to double kmem_cache_release().\n\nFix it by caching the RCU flag inside protected area, just like 'refcnt'"