On Sat, Dec 3, 2016 at 4:56 AM, Andrey Konovalov <andreyk...@google.com> wrote: > Hi! > > I'm seeing lots of the following error reports while running the > syzkaller fuzzer. > > Reports appeared when I updated to 3c49de52 (Dec 2) from 2caceb32 (Dec 1). > > ================================================================== > BUG: KASAN: use-after-free in worker_thread+0x17d8/0x18a0 > Read of size 8 at addr ffff880067f3ecd8 by task kworker/3:1/774 > > page:ffffea00019fce00 count:1 mapcount:0 mapping: (null) > index:0xffff880067f39c10 compound_mapcount: 0 > flags: 0x500000000004080(slab|head) > page dumped because: kasan: bad access detected > > CPU: 3 PID: 774 Comm: kworker/3:1 Not tainted 4.9.0-rc7+ #66 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > ffff88006c267838 ffffffff81f882da ffffffff6c25e338 1ffff1000d84ce9a > ffffed000d84ce92 ffff88006c25e340 0000000041b58ab3 ffffffff8541e198 > ffffffff81f88048 0000000100000000 0000000041b58ab3 ffffffff853d3ee8 > Call Trace: > [< inline >] __dump_stack lib/dump_stack.c:15 > [<ffffffff81f882da>] dump_stack+0x292/0x398 lib/dump_stack.c:51 > [< inline >] describe_address mm/kasan/report.c:262 > [<ffffffff817e50d1>] kasan_report_error+0x121/0x560 mm/kasan/report.c:368 > [< inline >] kasan_report mm/kasan/report.c:390 > [<ffffffff817e560e>] __asan_report_load8_noabort+0x3e/0x40 > mm/kasan/report.c:411 > [<ffffffff81329b88>] worker_thread+0x17d8/0x18a0 kernel/workqueue.c:2228 > [<ffffffff8133ebf3>] kthread+0x323/0x3e0 kernel/kthread.c:209 > [<ffffffff84a2a22a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Heck... this is the pending work vs. sk_destruct() race. :-/ We can't wait for the work in RCU callback, let me think about it...
