diff options
author | Eric Sandeen <sandeen@sandeen.net> | 2019-05-15 01:45:10 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-15 05:52:51 +0300 |
commit | 2ea622b887e74497ce5aac5bfe247502b5786f56 (patch) | |
tree | 3c17e664a47816f15b10e73a4c31a3dbc6e81b47 /lib | |
parent | a0edef79685c508fde517e6defac23b3ba60c422 (diff) | |
download | linux-2ea622b887e74497ce5aac5bfe247502b5786f56.tar.xz |
tools/testing/selftests/sysctl/sysctl.sh: add proc_do_large_bitmap() test case
The kernel has only two users of proc_do_large_bitmap(), the kernel CPU
watchdog, and the ip_local_reserved_ports. Refer to watchdog_cpumask
and ip_local_reserved_ports in Documentation for further details on
these. When you input a large buffer into these, when it is larger than
PAGE_SIZE- 1, the input data gets misparsed, and the user get
incorrectly informed that the desired input value was set. This commit
implements a test which mimics and exploits that use case, it uses a
bitmap size, as in the watchdog case. The bitmap is used to test the
bitmap proc handler, proc_do_large_bitmap().
The next commit fixes this issue.
[akpm@linux-foundation.org: move proc_do_large_bitmap() export to EOF]
[mcgrof@kernel.org: use new target description for backward compatibility]
[mcgrof@kernel.org: augment test number to 50, ran into issues with bash string comparisons when testing up to 50 cases.]
[mcgrof@kernel.org: introduce and use verify_diff_proc_file() to use diff]
[mcgrof@kernel.org: use mktemp for tmp file]
[mcgrof@kernel.org: merge shell test and C code]
[mcgrof@kernel.org: commit log love]
[mcgrof@kernel.org: export proc_do_large_bitmap() to allow for the test
[mcgrof@kernel.org: check for the return value when writing to the proc file]
Link: http://lkml.kernel.org/r/20190320222831.8243-6-mcgrof@kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/test_sysctl.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c index 3dd801c1c85b..566dad3f4196 100644 --- a/lib/test_sysctl.c +++ b/lib/test_sysctl.c @@ -47,6 +47,9 @@ struct test_sysctl_data { unsigned int uint_0001; char string_0001[65]; + +#define SYSCTL_TEST_BITMAP_SIZE 65536 + unsigned long *bitmap_0001; }; static struct test_sysctl_data test_data = { @@ -102,6 +105,13 @@ static struct ctl_table test_table[] = { .mode = 0644, .proc_handler = proc_dostring, }, + { + .procname = "bitmap_0001", + .data = &test_data.bitmap_0001, + .maxlen = SYSCTL_TEST_BITMAP_SIZE, + .mode = 0644, + .proc_handler = proc_do_large_bitmap, + }, { } }; @@ -129,15 +139,21 @@ static struct ctl_table_header *test_sysctl_header; static int __init test_sysctl_init(void) { + test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL); + if (!test_data.bitmap_0001) + return -ENOMEM; test_sysctl_header = register_sysctl_table(test_sysctl_root_table); - if (!test_sysctl_header) + if (!test_sysctl_header) { + kfree(test_data.bitmap_0001); return -ENOMEM; + } return 0; } late_initcall(test_sysctl_init); static void __exit test_sysctl_exit(void) { + kfree(test_data.bitmap_0001); if (test_sysctl_header) unregister_sysctl_table(test_sysctl_header); } |