lkml.org 
[lkml]   [2020]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.9 12/39] kernel/relay.c: fix memleak on destroy relay channel
    Date
    From: Wei Yongjun <weiyongjun1@huawei.com>

    commit 71e843295c680898959b22dc877ae3839cc22470 upstream.

    kmemleak report memory leak as follows:

    unreferenced object 0x607ee4e5f948 (size 8):
    comm "syz-executor.1", pid 2098, jiffies 4295031601 (age 288.468s)
    hex dump (first 8 bytes):
    00 00 00 00 00 00 00 00 ........
    backtrace:
    relay_open kernel/relay.c:583 [inline]
    relay_open+0xb6/0x970 kernel/relay.c:563
    do_blk_trace_setup+0x4a8/0xb20 kernel/trace/blktrace.c:557
    __blk_trace_setup+0xb6/0x150 kernel/trace/blktrace.c:597
    blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:738
    blkdev_ioctl+0xb2/0x6a0 block/ioctl.c:613
    block_ioctl+0xe5/0x120 fs/block_dev.c:1871
    vfs_ioctl fs/ioctl.c:48 [inline]
    __do_sys_ioctl fs/ioctl.c:753 [inline]
    __se_sys_ioctl fs/ioctl.c:739 [inline]
    __x64_sys_ioctl+0x170/0x1ce fs/ioctl.c:739
    do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

    'chan->buf' is malloced in relay_open() by alloc_percpu() but not free
    while destroy the relay channel. Fix it by adding free_percpu() before
    return from relay_destroy_channel().

    Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel buffer pointers")
    Reported-by: Hulk Robot <hulkci@huawei.com>
    Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: Michael Ellerman <mpe@ellerman.id.au>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Michel Lespinasse <walken@google.com>
    Cc: Daniel Axtens <dja@axtens.net>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Akash Goel <akash.goel@intel.com>
    Cc: <stable@vger.kernel.org>
    Link: http://lkml.kernel.org/r/20200817122826.48518-1-weiyongjun1@huawei.com
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    kernel/relay.c | 1 +
    1 file changed, 1 insertion(+)

    --- a/kernel/relay.c
    +++ b/kernel/relay.c
    @@ -196,6 +196,7 @@ free_buf:
    static void relay_destroy_channel(struct kref *kref)
    {
    struct rchan *chan = container_of(kref, struct rchan, kref);
    + free_percpu(chan->buf);
    kfree(chan);
    }


    \
     
     \ /
      Last update: 2020-08-24 10:52    [W:3.954 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site