==================================================================
BUG: KASAN: use-after-free in list_empty include/linux/list.h:282 [inline]
BUG: KASAN: use-after-free in waitqueue_active include/linux/wait.h:127 [inline]
BUG: KASAN: use-after-free in wq_has_sleeper include/linux/wait.h:161 [inline]
BUG: KASAN: use-after-free in skwq_has_sleeper include/net/sock.h:2142 [inline]
BUG: KASAN: use-after-free in sock_def_write_space+0x609/0x630 net/core/sock.c:2926
Read of size 8 at addr ffff888050369b00 by task syz-executor.5/14572

CPU: 0 PID: 14572 Comm: syz-executor.5 Not tainted 5.8.0-rc3-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 list_empty include/linux/list.h:282 [inline]
 waitqueue_active include/linux/wait.h:127 [inline]
 wq_has_sleeper include/linux/wait.h:161 [inline]
 skwq_has_sleeper include/net/sock.h:2142 [inline]
 sock_def_write_space+0x609/0x630 net/core/sock.c:2926
 sock_wfree+0x1cc/0x240 net/core/sock.c:2060
 skb_release_head_state+0x9f/0x250 net/core/skbuff.c:651
 skb_release_all net/core/skbuff.c:662 [inline]
 __kfree_skb net/core/skbuff.c:678 [inline]
 kfree_skb.part.0+0x89/0x350 net/core/skbuff.c:696
 kfree_skb+0x7d/0x100 include/linux/refcount.h:270
 skb_queue_purge+0x14/0x30 net/core/skbuff.c:3077
 qrtr_tun_release+0x40/0x60 net/qrtr/tun.c:118
 __fput+0x33c/0x880 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:135
 exit_task_work include/linux/task_work.h:25 [inline]
 do_exit+0xb72/0x2a40 kernel/exit.c:805
 do_group_exit+0x125/0x310 kernel/exit.c:903
 get_signal+0x40b/0x1ee0 kernel/signal.c:2743
 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:212 [inline]
 __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:246
 __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline]
 do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474
 entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138
RIP: 0023:0xf7f63569
Code: Bad RIP value.
RSP: 002b:00000000f5d5e12c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0
RAX: fffffffffffffe00 RBX: 000000000819af68 RCX: 0000000000000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000819af6c
RBP: 00000000f5d5e228 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6825:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 slab_post_alloc_hook mm/slab.h:586 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x12c/0x3b0 mm/slab.c:3484