Forwarded:

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@xxxxxxxxxxxxxxx, syzkaller-bugs@xxxxxxxxxxxxxxxx.

***

Subject: 
Author: nooraineqbal@xxxxxxxxx

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master

Resending this patch in the existing thread with a '#syz test:' directive
so syzbot can test it.

>From 1bb35c6722b8fb03e9262f6e6530d240629a44df Mon Sep 17 00:00:00 2001
From: neqbal <nooraineqbal@xxxxxxxxx>
Date: Sun, 28 Sep 2025 03:52:44 +0530
Subject: [PATCH] x86/mm: Fix off-by-one error in set_memory

Correct end page calculation by subtracting 1 to prevent
out-of-bounds access.

Reported-by: syzbot+e34177f6091df113ef20@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: neqbal <nooraineqbal@xxxxxxxxx>
---
 arch/x86/mm/pat/set_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index d2d54b8c4dbb..daefc96403f1 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -446,7 +446,7 @@ static void cpa_flush(struct cpa_data *cpa, int cache)
 	}
 
 	start = fix_addr(__cpa_addr(cpa, 0));
-	end =   fix_addr(__cpa_addr(cpa, cpa->numpages));
+	end =   fix_addr(__cpa_addr(cpa, cpa->numpages - 1));
 	if (cpa->force_flush_all)
 		end = TLB_FLUSH_ALL;
 
-- 
2.51.0