From: Rose <83477269+AtariDreams@users.noreply.github.com>
Date: Tue, 2 Jan 2024 15:13:27 +0000 (-0500)
Subject: basic: fix overflow detection in sigbus_pop
X-Git-Tag: v256-rc1~1322
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b4a9d19e4ec527a7b2d774a1349a6133f7739847;p=thirdparty%2Fsystemd.git

basic: fix overflow detection in sigbus_pop

The current check checks for n_sigbus_queue
being greater than or equal to SIGBUS_QUEUE_MAX,
when it should be just greater than as
n_sigbus_queue being SIGBUS_QUEUE_MAX indicates
that the queue is full, but not overflowed.
---

diff --git a/src/basic/sigbus.c b/src/basic/sigbus.c
index 7e5a493f6b0..47ab0b81d88 100644
--- a/src/basic/sigbus.c
+++ b/src/basic/sigbus.c
@@ -40,14 +40,14 @@ static void sigbus_push(void *addr) {
         }
 
         /* If we can't, make sure the queue size is out of bounds, to
-         * mark it as overflow */
+         * mark it as overflowed */
         for (;;) {
                 sig_atomic_t c;
 
                 __atomic_thread_fence(__ATOMIC_SEQ_CST);
                 c = n_sigbus_queue;
 
-                if (c > SIGBUS_QUEUE_MAX) /* already overflow */
+                if (c > SIGBUS_QUEUE_MAX) /* already overflowed */
                         return;
 
                 /* OK if we clobber c here, since we either immediately return
@@ -70,7 +70,7 @@ int sigbus_pop(void **ret) {
                 if (_likely_(c == 0))
                         return 0;
 
-                if (_unlikely_(c >= SIGBUS_QUEUE_MAX))
+                if (_unlikely_(c > SIGBUS_QUEUE_MAX))
                         return -EOVERFLOW;
 
                 for (u = 0; u < SIGBUS_QUEUE_MAX; u++) {