kernel_optimize_test/drivers/md/persistent-data
Hou Tao ba47e65a5d dm btree remove: assign new_root only when removal succeeds
commit b6e58b5466b2959f83034bead2e2e1395cca8aeb upstream.

remove_raw() in dm_btree_remove() may fail due to IO read error
(e.g. read the content of origin block fails during shadowing),
and the value of shadow_spine::root is uninitialized, but
the uninitialized value is still assign to new_root in the
end of dm_btree_remove().

For dm-thin, the value of pmd->details_root or pmd->root will become
an uninitialized value, so if trying to read details_info tree again
out-of-bound memory may occur as showed below:

  general protection fault, probably for non-canonical address 0x3fdcb14c8d7520
  CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6
  Hardware name: QEMU Standard PC
  RIP: 0010:metadata_ll_load_ie+0x14/0x30
  Call Trace:
   sm_metadata_count_is_more_than_one+0xb9/0xe0
   dm_tm_shadow_block+0x52/0x1c0
   shadow_step+0x59/0xf0
   remove_raw+0xb2/0x170
   dm_btree_remove+0xf4/0x1c0
   dm_pool_delete_thin_device+0xc3/0x140
   pool_message+0x218/0x2b0
   target_message+0x251/0x290
   ctl_ioctl+0x1c4/0x4d0
   dm_ctl_ioctl+0xe/0x20
   __x64_sys_ioctl+0x7b/0xb0
   do_syscall_64+0x40/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixing it by only assign new_root when removal succeeds

Signed-off-by: Hou Tao <houtao1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19 09:45:01 +02:00
..
dm-array.c
dm-array.h
dm-bitset.c
dm-bitset.h
dm-block-manager.c
dm-block-manager.h
dm-btree-internal.h dm persistent data: packed struct should have an aligned() attribute too 2021-05-11 14:47:40 +02:00
dm-btree-remove.c dm btree remove: assign new_root only when removal succeeds 2021-07-19 09:45:01 +02:00
dm-btree-spine.c
dm-btree.c
dm-btree.h
dm-persistent-data-internal.h
dm-space-map-common.c dm space map common: fix division bug in sm_ll_find_free_block() 2021-05-11 14:47:40 +02:00
dm-space-map-common.h dm persistent data: packed struct should have an aligned() attribute too 2021-05-11 14:47:40 +02:00
dm-space-map-disk.c dm space maps: don't reset space map allocation cursor when committing 2021-07-19 09:44:45 +02:00
dm-space-map-disk.h
dm-space-map-metadata.c dm space maps: don't reset space map allocation cursor when committing 2021-07-19 09:44:45 +02:00
dm-space-map-metadata.h
dm-space-map.h
dm-transaction-manager.c
dm-transaction-manager.h
Kconfig
Makefile