memory leak in create_pipe_files

From: syzbot <syzbot+6a137efd811917e8b53c@syzkaller.appspotmail.com>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk
Subject: memory leak in create_pipe_files
Date: Wed, 15 Jul 2020 01:39:17 -0700	[thread overview]
Message-ID: <000000000000fef5a905aa76dbf9@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    a581387e Merge tag 'io_uring-5.8-2020-07-10' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ba1967100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=13a9cfc3f50ff96
dashboard link: https://syzkaller.appspot.com/bug?extid=6a137efd811917e8b53c
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13d2004f100000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6a137efd811917e8b53c@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff88812a6c8800 (size 256):
  comm "syz-execprog", pid 6479, jiffies 4295096411 (age 83.520s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    20 2d 85 2a 81 88 ff ff 80 57 d2 15 81 88 ff ff   -.*.....W......
  backtrace:
    [<00000000057eb446>] kmem_cache_zalloc include/linux/slab.h:659 [inline]
    [<00000000057eb446>] __alloc_file+0x23/0x120 fs/file_table.c:101
    [<0000000046b459a4>] alloc_empty_file+0x4f/0xe0 fs/file_table.c:151
    [<00000000fced1caf>] alloc_file+0x31/0x160 fs/file_table.c:193
    [<0000000079549d8a>] alloc_file_pseudo+0xae/0x120 fs/file_table.c:233
    [<0000000058a70f71>] create_pipe_files+0x127/0x270 fs/pipe.c:931
    [<00000000ad5d09be>] __do_pipe_flags fs/pipe.c:964 [inline]
    [<00000000ad5d09be>] do_pipe2+0x43/0x110 fs/pipe.c:1012
    [<0000000038960906>] __do_sys_pipe2 fs/pipe.c:1030 [inline]
    [<0000000038960906>] __se_sys_pipe2 fs/pipe.c:1028 [inline]
    [<0000000038960906>] __x64_sys_pipe2+0x16/0x20 fs/pipe.c:1028
    [<00000000b1b64f40>] do_syscall_64+0x4c/0xe0 arch/x86/entry/common.c:384
    [<00000000e3fac4b7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88812a7abb80 (size 16):
  comm "syz-execprog", pid 6479, jiffies 4295096411 (age 83.520s)
  hex dump (first 16 bytes):
    01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000029e2bcd5>] kmem_cache_zalloc include/linux/slab.h:659 [inline]
    [<0000000029e2bcd5>] lsm_file_alloc security/security.c:567 [inline]
    [<0000000029e2bcd5>] security_file_alloc+0x2e/0xc0 security/security.c:1455
    [<00000000884a9f66>] __alloc_file+0x61/0x120 fs/file_table.c:106
    [<0000000046b459a4>] alloc_empty_file+0x4f/0xe0 fs/file_table.c:151
    [<00000000fced1caf>] alloc_file+0x31/0x160 fs/file_table.c:193
    [<0000000079549d8a>] alloc_file_pseudo+0xae/0x120 fs/file_table.c:233
    [<0000000058a70f71>] create_pipe_files+0x127/0x270 fs/pipe.c:931
    [<00000000ad5d09be>] __do_pipe_flags fs/pipe.c:964 [inline]
    [<00000000ad5d09be>] do_pipe2+0x43/0x110 fs/pipe.c:1012
    [<0000000038960906>] __do_sys_pipe2 fs/pipe.c:1030 [inline]
    [<0000000038960906>] __se_sys_pipe2 fs/pipe.c:1028 [inline]
    [<0000000038960906>] __x64_sys_pipe2+0x16/0x20 fs/pipe.c:1028
    [<00000000b1b64f40>] do_syscall_64+0x4c/0xe0 arch/x86/entry/common.c:384
    [<00000000e3fac4b7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

---
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