• Stephen Boyd's avatar
    clk: Fix double free due to devm_clk_register() · 293ba3b4
    Stephen Boyd authored
    Now that clk_unregister() frees the struct clk we're
    unregistering we'll free memory twice: first we'll call kfree()
    in __clk_release() with an address kmalloc doesn't know about and
    second we'll call kfree() in the devres layer. Remove the
    allocation of struct clk in devm_clk_register() and let
    clk_release() handle it. This fixes slab errors like:
    
    =============================================================================
    BUG kmalloc-128 (Not tainted): Invalid object pointer 0xed08e8d0
    -----------------------------------------------------------------------------
    
    Disabling lock debugging due to kernel taint
    INFO: Slab 0xeec503f8 objects=25 used=15 fp=0xed08ea00 flags=0x4081
    CPU: 2 PID: 73 Comm: rmmod Tainted: G    B         3.14.0-11032-g526e9c764381 #34
    [<c0014be0>] (unwind_backtrace) from [<c0012240>] (show_stack+0x10/0x14)
    [<c0012240>] (show_stack) from [<c04b74dc>] (dump_stack+0x70/0xbc)
    [<c04b74dc>] (dump_stack) from [<c00f6778>] (slab_err+0x74/0x84)
    [<c00f6778>] (slab_err) from [<c04b6278>] (free_debug_processing+0x2cc/0x31c)
    [<c04b6278>] (free_debug_processing) from [<c04b6300>] (__slab_free+0x38/0x41c)
    [<c04b6300>] (__slab_free) from [<c03931bc>] (clk_unregister+0xd4/0x140)
    [<c03931bc>] (clk_unregister) from [<c02fb774>] (release_nodes+0x164/0x1d8)
    [<c02fb774>] (release_nodes) from [<c02f8698>] (__device_release_driver+0x60/0xb0)
    [<c02f8698>] (__device_release_driver) from [<c02f9080>] (driver_detach+0xb4/0xb8)
    [<c02f9080>] (driver_detach) from [<c02f8480>] (bus_remove_driver+0x5c/0xc4)
    [<c02f8480>] (bus_remove_driver) from [<c008c9b8>] (SyS_delete_module+0x148/0x1d8)
    [<c008c9b8>] (SyS_delete_module) from [<c000ef80>] (ret_fast_syscall+0x0/0x48)
    FIX kmalloc-128: Object at 0xed08e8d0 not freed
    
    Fixes: fcb0ee6a (clk: Implement clk_unregister)
    Cc: Jiada Wang <jiada_wang@mentor.com>
    Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
    Cc: Kyungmin Park <kyungmin.park@samsung.com>
    Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
    Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
    Cc: stable@vger.kernel.org
    293ba3b4
clk.c 63.2 KB