• Michael Ellerman's avatar
    drivers/macintosh: Fix memleak in windfarm_pm112 driver · 93900337
    Michael Ellerman authored
    create_cpu_loop() calls smu_sat_get_sdb_partition() which does
    kmalloc() and returns the allocated buffer. In fact it's called twice,
    and neither buffer is freed.
    
    This results in a memory leak as reported by Erhard:
      unreferenced object 0xc00000047081f840 (size 32):
        comm "kwindfarm", pid 203, jiffies 4294880630 (age 5552.877s)
        hex dump (first 32 bytes):
          c8 06 02 7f ff 02 ff 01 fb bf 00 41 00 20 00 00  ...........A. ..
          00 07 89 37 00 a0 00 00 00 00 00 00 00 00 00 00  ...7............
        backtrace:
          [<0000000083f0a65c>] .smu_sat_get_sdb_partition+0xc4/0x2d0 [windfarm_smu_sat]
          [<000000003010fcb7>] .pm112_wf_notify+0x104c/0x13bc [windfarm_pm112]
          [<00000000b958b2dd>] .notifier_call_chain+0xa8/0x180
          [<0000000070490868>] .blocking_notifier_call_chain+0x64/0x90
          [<00000000131d8149>] .wf_thread_func+0x114/0x1a0
          [<000000000d54838d>] .kthread+0x13c/0x190
          [<00000000669b72bc>] .ret_from_kernel_thread+0x58/0x64
      unreferenced object 0xc0000004737089f0 (size 16):
        comm "kwindfarm", pid 203, jiffies 4294880879 (age 5552.050s)
        hex dump (first 16 bytes):
          c4 04 01 7f 22 11 e0 e6 ff 55 7b 12 ec 11 00 00  ...."....U{.....
        backtrace:
          [<0000000083f0a65c>] .smu_sat_get_sdb_partition+0xc4/0x2d0 [windfarm_smu_sat]
          [<00000000b94ef7e1>] .pm112_wf_notify+0x1294/0x13bc [windfarm_pm112]
          [<00000000b958b2dd>] .notifier_call_chain+0xa8/0x180
          [<0000000070490868>] .blocking_notifier_call_chain+0x64/0x90
          [<00000000131d8149>] .wf_thread_func+0x114/0x1a0
          [<000000000d54838d>] .kthread+0x13c/0x190
          [<00000000669b72bc>] .ret_from_kernel_thread+0x58/0x64
    
    Fix it by rearranging the logic so we deal with each buffer
    separately, which then makes it easy to free the buffer once we're
    done with it.
    
    Fixes: ac171c46 ("[PATCH] powerpc: Thermal control for dual core G5s")
    Cc: stable@vger.kernel.org # v2.6.16+
    Reported-by: default avatarErhard F. <erhard_f@mailbox.org>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    Tested-by: default avatarErhard F. <erhard_f@mailbox.org>
    Link: https://lore.kernel.org/r/20200423060038.3308530-1-mpe@ellerman.id.au
    93900337
windfarm_pm112.c 18 KB