[PATCH] isofs: fix undefined behavior in iso_date()

From: Linke Li
Date: Sun Jul 09 2023 - 02:51:29 EST


From: Linke Li <lilinke99@xxxxxxxxx>

Fix undefined behavior in the code by properly handling the left shift operaion.
Instead of left-shifting a negative value, explicitly cast -1 to an unsigned int
before the shift. This ensures well defined behavior and resolves any potential
issues.

Signed-off-by: Linke Li <lilinke99@xxxxxxxxx>
---
fs/isofs/util.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/isofs/util.c b/fs/isofs/util.c
index e88dba721661..4c902901401a 100644
--- a/fs/isofs/util.c
+++ b/fs/isofs/util.c
@@ -37,7 +37,7 @@ int iso_date(u8 *p, int flag)

/* sign extend */
if (tz & 0x80)
- tz |= (-1 << 8);
+ tz |= ((unsigned int)-1 << 8);

/*
* The timezone offset is unreliable on some disks,
--
2.25.1