KASAN: user-memory-access Read in filp_close (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d31958b3 Add linux-next specific files for 20200710
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11cbc800900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3fe4fccb94cbc1a6
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec02913b4e4d22f3045
compiler:       gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5ec02913b4e4d22f3045@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: user-memory-access in instrument_atomic_read include/linux/instrumented.h:56 [inline]
BUG: KASAN: user-memory-access in atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
BUG: KASAN: user-memory-access in atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
BUG: KASAN: user-memory-access in filp_close+0x22/0x170 fs/open.c:1270
Read of size 8 at addr 00000000070007ef by task syz-executor.1/14036

CPU: 0 PID: 14036 Comm: syz-executor.1 Not tainted 5.8.0-rc4-next-20200710-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
 __kasan_report mm/kasan/report.c:517 [inline]
 kasan_report.cold+0x5/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 instrument_atomic_read include/linux/instrumented.h:56 [inline]
 atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
 atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
 filp_close+0x22/0x170 fs/open.c:1270
 __close_fd+0x2f/0x50 fs/file.c:671
 __do_sys_close fs/open.c:1295 [inline]
 __se_sys_close fs/open.c:1293 [inline]
 __x64_sys_close+0x69/0x100 fs/open.c:1293
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416721
Code: Bad RIP value.
RSP: 002b:00007fff8ed6e800 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 0000000000416721
RDX: 0000000000000000 RSI: 000000000000023e RDI: 0000000000000007
RBP: 0000000000000001 R08: 000000003293423e R09: 0000000032934242
R10: 00007fff8ed6e8f0 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078c04c
==================================================================


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