On Mon, Dec 19, 2022 at 12:04:43AM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 13e3c7793e2f Merge tag 'for-netdev' of https://git.kernel... > git tree: bpf > console+strace: https://syzkaller.appspot.com/x/log.txt?x=177df7e0480000 > kernel config: https://syzkaller.appspot.com/x/.config?x=b0e91ad4b5f69c47 > dashboard link: https://syzkaller.appspot.com/bug?extid=b8e8c01c8ade4fe6e48f > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15e87100480000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ceeb13880000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/373a99daa295/disk-13e3c779.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/7fa71ed0fe17/vmlinux-13e3c779.xz > kernel image: https://storage.googleapis.com/syzbot-assets/2842ad5c698b/bzImage-13e3c779.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+b8e8c01c8ade4fe6e48f@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: use-after-free in __lock_acquire+0x3ee7/0x56d0 kernel/locking/lockdep.c:4925 > Read of size 8 at addr ffff8880237d6018 by task syz-executor287/8300 > > CPU: 0 PID: 8300 Comm: syz-executor287 Not tainted 6.1.0-syzkaller-09661-g13e3c7793e2f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 > print_address_description mm/kasan/report.c:284 [inline] > print_report+0x15e/0x45d mm/kasan/report.c:395 > kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 > __lock_acquire+0x3ee7/0x56d0 kernel/locking/lockdep.c:4925 > lock_acquire kernel/locking/lockdep.c:5668 [inline] > lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 > put_pmu_ctx kernel/events/core.c:4913 [inline] > put_pmu_ctx+0xad/0x390 kernel/events/core.c:4893 > _free_event+0x3c5/0x13d0 kernel/events/core.c:5196 > free_event+0x58/0xc0 kernel/events/core.c:5224 > __do_sys_perf_event_open+0x66d/0x2980 kernel/events/core.c:12701 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd Does this help? diff --git a/kernel/events/core.c b/kernel/events/core.c index e47914ac8732..bbff551783e1 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -12689,7 +12689,8 @@ SYSCALL_DEFINE5(perf_event_open, return event_fd; err_context: - /* event->pmu_ctx freed by free_event() */ + put_pmu_ctx(event->pmu_ctx); + event->pmu_ctx = NULL; /* _free_event() */ err_locked: mutex_unlock(&ctx->mutex); perf_unpin_context(ctx);
