On 5/16/20 10:30 PM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: ac935d22 Add linux-next specific files for 20200415 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=12deaa5e100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019 > dashboard link: https://syzkaller.appspot.com/bug?extid=8c91f5d054e998721c57 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d54c02100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17461e06100000 > > The bug was bisected to: > > commit b41e98524e424d104aa7851d54fd65820759875a > Author: Jens Axboe <axboe@xxxxxxxxx> > Date: Mon Feb 17 16:52:41 2020 +0000 > > io_uring: add per-task callback handler > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1488dc3c100000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=1688dc3c100000 > console output: https://syzkaller.appspot.com/x/log.txt?x=1288dc3c100000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+8c91f5d054e998721c57@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: b41e98524e42 ("io_uring: add per-task callback handler") > > RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 > RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b > RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260 > R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000 > INFO: trying to register non-static key. > the code is fine but needs lockdep annotation. > turning off the locking correctness validator. > CPU: 1 PID: 7090 Comm: syz-executor222 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x188/0x20d lib/dump_stack.c:118 > assign_lock_key kernel/locking/lockdep.c:913 [inline] > register_lock_class+0x1664/0x1760 kernel/locking/lockdep.c:1225 > __lock_acquire+0x104/0x4c50 kernel/locking/lockdep.c:4234 > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 > __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:122 > io_cqring_ev_posted+0xa5/0x1e0 fs/io_uring.c:1160 > io_poll_remove_all fs/io_uring.c:4357 [inline] > io_ring_ctx_wait_and_kill+0x2bc/0x5a0 fs/io_uring.c:7305 > io_uring_create fs/io_uring.c:7843 [inline] > io_uring_setup+0x115e/0x22b0 fs/io_uring.c:7870 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 I think this will likely fix it. diff --git a/fs/io_uring.c b/fs/io_uring.c index 70ae7e840c85..79c90eb28c0d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -924,6 +924,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) goto err; ctx->flags = p->flags; + init_waitqueue_head(&ctx->sqo_wait); init_waitqueue_head(&ctx->cq_wait); INIT_LIST_HEAD(&ctx->cq_overflow_list); init_completion(&ctx->completions[0]); @@ -6837,7 +6838,6 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx, { int ret; - init_waitqueue_head(&ctx->sqo_wait); mmgrab(current->mm); ctx->sqo_mm = current->mm; -- Jens Axboe
