Re: memory leak in xdp_umem_create

[Magnus Karlsson]

On Fri, Oct 23, 2020 at 6:24 PM syzbot
<syzbot+eb71df123dc2be2c1456@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    f804b315 Merge tag 'linux-watchdog-5.10-rc1' of git://www...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1797677f900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=504c0405f28172a
> dashboard link: https://syzkaller.appspot.com/bug?extid=eb71df123dc2be2c1456
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10f27544500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12fc4de8500000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+eb71df123dc2be2c1456@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> Warning: Permanently added '10.128.10.22' (ECDSA) to the list of known hosts.
> executing program
> executing program
> BUG: memory leak
> unreferenced object 0xffff888110c1e400 (size 96):
>   comm "syz-executor230", pid 8462, jiffies 4294942469 (age 13.280s)
>   hex dump (first 32 bytes):
>     00 50 e0 00 00 c9 ff ff 00 00 02 00 00 00 00 00  .P..............
>     00 00 00 00 00 10 00 00 20 00 00 00 20 00 00 00  ........ ... ...
>   backtrace:
>     [<00000000c4608c2b>] kmalloc include/linux/slab.h:554 [inline]
>     [<00000000c4608c2b>] kzalloc include/linux/slab.h:666 [inline]
>     [<00000000c4608c2b>] xdp_umem_create+0x33/0x630 net/xdp/xdp_umem.c:229
>     [<00000000551a05ed>] xsk_setsockopt+0x4ad/0x590 net/xdp/xsk.c:852
>     [<00000000f143ff32>] __sys_setsockopt+0x1b0/0x360 net/socket.c:2132
>     [<0000000076c65982>] __do_sys_setsockopt net/socket.c:2143 [inline]
>     [<0000000076c65982>] __se_sys_setsockopt net/socket.c:2140 [inline]
>     [<0000000076c65982>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2140
>     [<00000000d47a7174>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<00000000fb8e5852>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff88810e018f00 (size 256):
>   comm "syz-executor230", pid 8462, jiffies 4294942469 (age 13.280s)
>   hex dump (first 32 bytes):
>     00 00 4f 04 00 ea ff ff 40 00 4f 04 00 ea ff ff  ..O.....@.O.....
>     80 00 4f 04 00 ea ff ff c0 00 4f 04 00 ea ff ff  ..O.......O.....
>   backtrace:
>     [<00000000257d0c74>] kmalloc_array include/linux/slab.h:594 [inline]
>     [<00000000257d0c74>] kcalloc include/linux/slab.h:605 [inline]
>     [<00000000257d0c74>] xdp_umem_pin_pages net/xdp/xdp_umem.c:89 [inline]
>     [<00000000257d0c74>] xdp_umem_reg net/xdp/xdp_umem.c:207 [inline]
>     [<00000000257d0c74>] xdp_umem_create+0x3cc/0x630 net/xdp/xdp_umem.c:240
>     [<00000000551a05ed>] xsk_setsockopt+0x4ad/0x590 net/xdp/xsk.c:852
>     [<00000000f143ff32>] __sys_setsockopt+0x1b0/0x360 net/socket.c:2132
>     [<0000000076c65982>] __do_sys_setsockopt net/socket.c:2143 [inline]
>     [<0000000076c65982>] __se_sys_setsockopt net/socket.c:2140 [inline]
>     [<0000000076c65982>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2140
>     [<00000000d47a7174>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<00000000fb8e5852>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
>
>
> ---
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>
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Thank you Mr Syzbot! I will take a look at this.