TOMOYO: Fix infinite loop bug when reading /sys/kernel/security/tomoyo/audit
In tomoyo_flush(), head->r.w[0] holds pointer to string data to be printed.
But head->r.w[0] was updated only when the string data was partially
printed (because head->r.w[0] will be updated by head->r.w[1] later if
completely printed). However, regarding /sys/kernel/security/tomoyo/query ,
an additional '\0' is printed after the string data was completely printed.
But if free space for read buffer became 0 before printing the additional '\0',
tomoyo_flush() was returning without updating head->r.w[0]. As a result,
tomoyo_flush() forever reprints already printed string data.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 2b7b1a1..a0d09e5 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -108,10 +108,9 @@
head->read_user_buf += len;
w += len;
}
- if (*w) {
- head->r.w[0] = w;
+ head->r.w[0] = w;
+ if (*w)
return false;
- }
/* Add '\0' for query. */
if (head->poll) {
if (!head->read_user_buf_avail ||