diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-31 13:57:58 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-31 14:01:48 +0100 |
| commit | 2c1cf00eeacb784781cf1c9896b8af001246d339 (patch) | |
| tree | e07175f82ea5708dd8f5ad744a8ba4e3c5dcd715 | |
| parent | 37ea7b630ae5cdea4e8ff381d9d23abfef5939e6 (diff) | |
| download | lwn-2c1cf00eeacb784781cf1c9896b8af001246d339.tar.gz lwn-2c1cf00eeacb784781cf1c9896b8af001246d339.zip | |
relay: check return of create_buf_file() properly
If create_buf_file() returns an error, don't try to reference it later
as a valid dentry pointer.
This problem was exposed when debugfs started to return errors instead
of just NULL for some calls when they do not succeed properly.
Also, the check for WARN_ON(dentry) was just wrong :)
Reported-by: Kees Cook <keescook@chromium.org>
Reported-and-tested-by: syzbot+16c3a70e1e9b29346c43@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/relay.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/relay.c b/kernel/relay.c index 04f248644e06..9e0f52375487 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -428,6 +428,8 @@ static struct dentry *relay_create_buf_file(struct rchan *chan, dentry = chan->cb->create_buf_file(tmpname, chan->parent, S_IRUSR, buf, &chan->is_global); + if (IS_ERR(dentry)) + dentry = NULL; kfree(tmpname); @@ -461,7 +463,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) dentry = chan->cb->create_buf_file(NULL, NULL, S_IRUSR, buf, &chan->is_global); - if (WARN_ON(dentry)) + if (IS_ERR_OR_NULL(dentry)) goto free_buf; } |