git: 933490d3b6d4 - stable/14 - kasan: fix false-positive kasan_report upon thread reuse

The branch stable/14 has been updated by khng:

URL: https://cgit.FreeBSD.org/src/commit/?id=933490d3b6d43f7ad1dd5d8720fb2f7774d7f26e

commit 933490d3b6d43f7ad1dd5d8720fb2f7774d7f26e
Author:     Ka Ho Ng <khng@FreeBSD.org>
AuthorDate: 2024-04-19 19:18:27 +0000
Commit:     Ka Ho Ng <khng@FreeBSD.org>
CommitDate: 2024-04-22 00:30:58 +0000

    kasan: fix false-positive kasan_report upon thread reuse
    
    In fork1(), if a thread is reused and thread_alloc_stack() is not
    called, mark the reused thread's kstack pages clean in the KASAN shadow
    buffer.
    
    Sponsored by:   Juniper Networks, Inc.
    MFC after:      3 days
    Reviewed by:    markj
    Differential Revision:  https://reviews.freebsd.org/D44875
    
    (cherry picked from commit 68a3a7fc94833020403190c20bd9be186c6156ce)
---
 sys/kern/kern_fork.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index edcd8a1f2139..9bbe7c8a8153 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -42,6 +42,7 @@
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/asan.h>
 #include <sys/bitstring.h>
 #include <sys/sysproto.h>
 #include <sys/eventhandler.h>
@@ -1028,6 +1029,10 @@ fork1(struct thread *td, struct fork_req *fr)
 				error = ENOMEM;
 				goto fail2;
 			}
+		} else {
+			kasan_mark((void *)td2->td_kstack,
+			    ptoa(td2->td_kstack_pages),
+			    ptoa(td2->td_kstack_pages), 0);
 		}
 	}