• John Garry's avatar
    ipmi: use dynamic memory for DMI driver override · 765ae618
    John Garry authored
    commit 5516e21a upstream.
    
    Currently a crash can be seen if we reach the "err"
    label in dmi_add_platform_ipmi(), calling
    platform_device_put(), like here:
    [    7.270584]  (null): ipmi:dmi: Unable to add resources: -16
    [    7.330229] ------------[ cut here ]------------
    [    7.334889] kernel BUG at mm/slub.c:3894!
    [    7.338936] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
    [    7.344475] Modules linked in:
    [    7.347556] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2-00004-gbe9cb7b-dirty #114
    [    7.355907] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT17 Nemo 2.0 RC0 11/29/2017
    [    7.365137] task: 00000000c211f6d3 task.stack: 00000000f276e9af
    [    7.371116] pstate: 60000005 (nZCv daif -PAN -UAO)
    [    7.375957] pc : kfree+0x194/0x1b4
    [    7.379389] lr : platform_device_release+0xcc/0xd8
    [    7.384225] sp : ffff0000092dba90
    [    7.387567] x29: ffff0000092dba90 x28: ffff000008a83000
    [    7.392933] x27: ffff0000092dbc10 x26: 00000000000000e6
    [    7.398297] x25: 0000000000000003 x24: ffff0000085b51e8
    [    7.403662] x23: 0000000000000100 x22: ffff7e0000234cc0
    [    7.409027] x21: ffff000008af3660 x20: ffff8017d21acc10
    [    7.414392] x19: ffff8017d21acc00 x18: 0000000000000002
    [    7.419757] x17: 0000000000000001 x16: 0000000000000008
    [    7.425121] x15: 0000000000000001 x14: 6666666678303d65
    [    7.430486] x13: 6469727265766f5f x12: 7265766972642e76
    [    7.435850] x11: 6564703e2d617020 x10: 6530326435373638
    [    7.441215] x9 : 3030303030303030 x8 : 3d76656420657361
    [    7.446580] x7 : ffff000008f59df8 x6 : ffff8017fbe0ea50
    [    7.451945] x5 : 0000000000000000 x4 : 0000000000000000
    [    7.457309] x3 : ffffffffffffffff x2 : 0000000000000000
    [    7.462674] x1 : 0fffc00000000800 x0 : ffff7e0000234ce0
    [    7.468039] Process swapper/0 (pid: 1, stack limit = 0x00000000f276e9af)
    [    7.474809] Call trace:
    [    7.477272]  kfree+0x194/0x1b4
    [    7.480351]  platform_device_release+0xcc/0xd8
    [    7.484837]  device_release+0x34/0x90
    [    7.488531]  kobject_put+0x70/0xcc
    [    7.491961]  put_device+0x14/0x1c
    [    7.495304]  platform_device_put+0x14/0x1c
    [    7.499439]  dmi_add_platform_ipmi+0x348/0x3ac
    [    7.503923]  scan_for_dmi_ipmi+0xfc/0x10c
    [    7.507970]  do_one_initcall+0x38/0x124
    [    7.511840]  kernel_init_freeable+0x188/0x228
    [    7.516238]  kernel_init+0x10/0x100
    [    7.519756]  ret_from_fork+0x10/0x18
    [    7.523362] Code: f94002c0 37780080 f94012c0 37000040 (d4210000)
    [    7.529552] ---[ end trace 11750e4787deef9e ]---
    [    7.534228] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
    [    7.534228]
    
    This is because when the device is released in
    platform_device_release(), we try to free
    pdev.driver_override. This is a const string, hence
    the crash.
    Fix by using dynamic memory for pdev->driver_override.
    Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
    [Removed the free of driver_override from ipmi_si_remove_by_dev().  The
     free is done in platform_device_release(), and would result in a double
     free, and ipmi_si_remove_by_dev() is called by non-platform devices.]
    Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    765ae618