• Jesper Juhl's avatar
    backlight: Fix cr_bllcd allocations and error paths · 0b75f2df
    Jesper Juhl authored
    After fixing the too small memory allocation in cr_backlight_probe()
    from drivers/video/backlight/cr_bllcd.c
    (commit e3bbb3f0) I noticed that the
    Coverity checker also thought there were a few memory leaks in there.
    I took a closer look and confirmed that there were indeed several
    leaks.
    
    At the start of the function we allocate storage for a
    'struct cr_panel' and store the pointer in a variable named 'crp'.
    
    Then we call pci_get_device() and pci_read_config_byte() and if
    either of them fail we return without freeing the memory allocated
    for the 'struct cr_panel'. These two leaks are easy to fix since we
    don't even use 'crp' for anything up to this point, so I simply
    moved the allocation further down in the function so it only happens
    just before we actually need it.
    
    A bit further down we call backlight_device_register() and store the
    result in 'crp->cr_backlight_device'. In case of error we return
    'crp->cr_backlight_device' from the function, thus leaking 'crp'
    itself. The same thing happens with the call to lcd_device_register().
    To fix these two leaks I declare two new pointers to hold the return
    values, so that in case of error we can return the pointer (as before)
    but without leaking 'crp'.
    
    This version of the patch also adds missing
    backlight_device_unregister() / lcd_device_unregister() / pci_dev_put()
    calls to error paths.
      Thanks to Richard Purdie <rpurdie@rpsys.net> for noticing.
    Signed-off-by: default avatarJesper Juhl <jesper.juhl@gmail.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarRichard Purdie <rpurdie@rpsys.net>
    0b75f2df
cr_bllcd.c 7.29 KB