linux/mm/damon
SeongJae Park 48998c1773 mm/damon/dbgfs: check if rm_contexts input is for a real context
commit 1de09a7281 upstream.

A user could write a name of a file under 'damon/' debugfs directory,
which is not a user-created context, to 'rm_contexts' file.  In the case,
'dbgfs_rm_context()' just assumes it's the valid DAMON context directory
only if a file of the name exist.  As a result, invalid memory access
could happen as below.  Fix the bug by checking if the given input is for
a directory.  This check can filter out non-context inputs because
directories under 'damon/' debugfs directory can be created via only
'mk_contexts' file.

This bug has found by syzbot[1].

[1] https://lore.kernel.org/damon/000000000000ede3ac05ec4abf8e@google.com/

Link: https://lkml.kernel.org/r/20221107165001.5717-2-sj@kernel.org
Fixes: 75c1c2b53c ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: syzbot+6087eafb76a94c4ac9eb@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>	[5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-16 09:58:27 +01:00
..
core-test.h mm/damon/core-test: fix wrong expectations for 'damon_split_regions_of()' 2021-10-28 17:18:55 -07:00
core.c mm/damon/core: fix fake load reports due to uninterruptible sleeps 2021-12-14 10:57:11 +01:00
dbgfs-test.h mm/damon: don't use strnlen() with known-bogus source length 2021-09-24 16:13:34 -07:00
dbgfs.c mm/damon/dbgfs: check if rm_contexts input is for a real context 2022-11-16 09:58:27 +01:00
Kconfig mm/damon: add kunit tests 2021-09-08 11:50:25 -07:00
Makefile mm/damon: implement a debugfs-based user space interface 2021-09-08 11:50:24 -07:00
vaddr-test.h mm/damon: add kunit tests 2021-09-08 11:50:25 -07:00
vaddr.c mm/damon: validate if the pmd entry is present before accessing 2022-10-26 12:34:24 +02:00