Re: [PATCH v2] soc: dpio: fix cleanup on error

[Ioana Ciornei]

On Mon, Oct 04, 2021 at 02:53:23PM +0300, Laurentiu Tudor wrote:
> dpaa2_io_service_register() adds an element to a linked list but
> doesn't remove it on the error path, leading to the below kasan
> use-after-free splat. Fix it.
> 
> ==================================================================
> BUG: KASAN: use-after-free in dpaa2_io_service_register+0xb8/0x1d4
> Write of size 8 at addr ffff05d2b13af028 by task kworker/u32:2/151
> 
> CPU: 9 PID: 151 Comm: kworker/u32:2 Not tainted 5.14.0-rc1-00222
> Hardware name: NXP NXP LX2160ARDB Platform, BIOS EDK II Apr 16 2021
> Workqueue: events_unbound deferred_probe_work_func
> Call trace:
>  dump_backtrace+0x0/0x2a4
>  show_stack+0x1c/0x30
>  dump_stack_lvl+0x68/0x84
>  print_address_description.constprop.0+0x74/0x2b8
>  kasan_report+0x1e0/0x24c
>  __asan_store8+0xa8/0xd0
>  dpaa2_io_service_register+0xb8/0x1d4
>  dpaa2_eth_probe+0x93c/0x21cc
>  fsl_mc_driver_probe+0x3c/0x80
>  really_probe.part.0+0xec/0x480
>  __driver_probe_device+0xd4/0x180
>  driver_probe_device+0xf8/0x1e0
>  __device_attach_driver+0x120/0x190
>  bus_for_each_drv+0xec/0x15c
>  __device_attach+0x168/0x250
>  device_initial_probe+0x18/0x24
>  bus_probe_device+0xec/0x100
>  deferred_probe_work_func+0xe8/0x130
>  process_one_work+0x3b8/0x650
>  worker_thread+0xa4/0x72c
>  kthread+0x1f8/0x210
>  ret_from_fork+0x10/0x18
> 
> Allocated by task 1192:
>  kasan_save_stack+0x2c/0x60
>  __kasan_kmalloc+0x90/0xb4
>  dpaa2_eth_probe+0x830/0x21cc
>  fsl_mc_driver_probe+0x3c/0x80
>  really_probe.part.0+0xec/0x480
>  __driver_probe_device+0xd4/0x180
>  driver_probe_device+0xf8/0x1e0
>  __device_attach_driver+0x120/0x190
>  bus_for_each_drv+0xec/0x15c
>  __device_attach+0x168/0x250
>  device_initial_probe+0x18/0x24
>  bus_probe_device+0xec/0x100
>  device_add+0x570/0xca0
>  fsl_mc_device_add+0x360/0x8f0
>  fsl_mc_obj_device_add+0x140/0x16c
>  dprc_scan_objects+0x2c4/0x480
>  dprc_probe+0x48/0x17c
>  fsl_mc_driver_probe+0x3c/0x80
>  really_probe.part.0+0xec/0x480
>  __driver_probe_device+0xd4/0x180
>  device_driver_attach+0x70/0xf0
>  bind_store+0xf8/0x160
>  drv_attr_store+0x50/0x6c
>  sysfs_kf_write+0x94/0xb0
>  kernfs_fop_write_iter+0x19c/0x264
>  new_sync_write+0x1c4/0x2bc
>  vfs_write+0x30c/0x390
>  ksys_write+0xc4/0x170
>  __arm64_sys_write+0x48/0x60
>  invoke_syscall+0x60/0x190
>  el0_svc_common+0x84/0x130
>  do_el0_svc+0x88/0xa4
>  el0_svc+0x24/0x34
>  el0t_64_sync_handler+0xa8/0x130
>  el0t_64_sync+0x198/0x19c
> 
> Freed by task 1192:
>  kasan_save_stack+0x2c/0x60
>  kasan_set_track+0x2c/0x40
>  kasan_set_free_info+0x2c/0x50
>  __kasan_slab_free+0xdc/0x140
>  kfree+0xd4/0x360
>  dpaa2_eth_probe+0x11b4/0x21cc
>  fsl_mc_driver_probe+0x3c/0x80
>  really_probe.part.0+0xec/0x480
>  __driver_probe_device+0xd4/0x180
>  driver_probe_device+0xf8/0x1e0
>  __device_attach_driver+0x120/0x190
>  bus_for_each_drv+0xec/0x15c
>  __device_attach+0x168/0x250
>  device_initial_probe+0x18/0x24
>  bus_probe_device+0xec/0x100
>  device_add+0x570/0xca0
>  fsl_mc_device_add+0x360/0x8f0
>  fsl_mc_obj_device_add+0x140/0x16c
>  dprc_scan_objects+0x2c4/0x480
>  dprc_probe+0x48/0x17c
>  fsl_mc_driver_probe+0x3c/0x80
>  really_probe.part.0+0xec/0x480
>  __driver_probe_device+0xd4/0x180
>  device_driver_attach+0x70/0xf0
>  bind_store+0xf8/0x160
>  drv_attr_store+0x50/0x6c
>  sysfs_kf_write+0x94/0xb0
>  kernfs_fop_write_iter+0x19c/0x264
>  new_sync_write+0x1c4/0x2bc
>  vfs_write+0x30c/0x390
>  ksys_write+0xc4/0x170
>  __arm64_sys_write+0x48/0x60
>  invoke_syscall+0x60/0x190
>  el0_svc_common+0x84/0x130
>  do_el0_svc+0x88/0xa4
>  el0_svc+0x24/0x34
>  el0t_64_sync_handler+0xa8/0x130
>  el0t_64_sync+0x198/0x19c
> 
> The buggy address belongs to the object at ffff05d2b13af000
>  which belongs to the cache kmalloc-1k of size 1024
> The buggy address is located 40 bytes inside of
>  1024-byte region [ffff05d2b13af000, ffff05d2b13af400)
> The buggy address belongs to the page:
> page:0000000091873dc7 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22313a8
> head:0000000091873dc7 order:3 compound_mapcount:0 compound_pincount:0
> flags: 0xbfffc0000010200(slab|head|node=0|zone=2|lastcpupid=0xffff)
> raw: 0bfffc0000010200 0000000000000000 dead000000000122 ffff05d1000028c0
> raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
> 
> Memory state around the buggy address:
>  ffff05d2b13aef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>  ffff05d2b13aef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> >ffff05d2b13af000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                                   ^
>  ffff05d2b13af080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff05d2b13af100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
> 
> Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

Reviewed-by: Ioana Ciornei <ioana.ciornei@xxxxxxx>