f4c5eebb37
commit cb65b282c9640c27d3129e2e04b711ce1b352838 upstream.
Must check pmd->fail_io before using pmd->data_sm since
pmd->data_sm may be destroyed by other processes.
P1(kworker) P2(message)
do_worker
process_prepared
process_prepared_discard_passdown_pt2
dm_pool_dec_data_range
pool_message
commit
dm_pool_commit_metadata
↓
// commit failed
metadata_operation_failed
abort_transaction
dm_pool_abort_metadata
__open_or_format_metadata
↓
dm_sm_disk_open
↓
// open failed
// pmd->data_sm is NULL
dm_sm_dec_blocks
↓
// try to access pmd->data_sm --> UAF
As shown above, if dm_pool_commit_metadata() and
dm_pool_abort_metadata() fail in pool_message process, kworker may
trigger UAF.
Fixes: be500ed721a6 ("dm space maps: improve performance with inc/dec on ranges of blocks")
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.