git: 009268dbfdd5 - stable/14 - hwpmc: On attach, fix allowing a PMC's owner to attach it to itself

From: Olivier Certner <olce_at_FreeBSD.org>
Date: Thu, 18 Sep 2025 10:13:42 UTC
The branch stable/14 has been updated by olce:

URL: https://cgit.FreeBSD.org/src/commit/?id=009268dbfdd5fe487117654f75ae3850a2c1a7d9

commit 009268dbfdd5fe487117654f75ae3850a2c1a7d9
Author:     Olivier Certner <olce@FreeBSD.org>
AuthorDate: 2025-09-09 12:48:05 +0000
Commit:     Olivier Certner <olce@FreeBSD.org>
CommitDate: 2025-09-18 10:13:10 +0000

    hwpmc: On attach, fix allowing a PMC's owner to attach it to itself
    
    The returned value in this case was wrong, and would basically prevent
    some PMC's owner process to attach that PMC to itself although the
    security checks underneath would have allowed it.
    
    Now that this early return has been fixed, its block basically becomes
    a performance short-circuit which has no effect from a functional
    standpoint.
    
    Fixes:          ebccf1e3a6b1 ("Bring a working snapshot of hwpmc(4), ...")
    MFC after:      9 days
    Sponsored by:   The FreeBSD Foundation
    
    (cherry picked from commit 1c40b15971f09c0c0676ae476b88b32166eae8ac)
---
 sys/dev/hwpmc/hwpmc_mod.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c
index 21f416510d5e..54fcc2dafb4f 100644
--- a/sys/dev/hwpmc/hwpmc_mod.c
+++ b/sys/dev/hwpmc/hwpmc_mod.c
@@ -1042,7 +1042,7 @@ pmc_can_attach(struct pmc *pm, struct proc *t)
 	 */
 
 	if ((o = pm->pm_owner->po_owner) == t)
-		return (false);
+		return (true);
 
 	PROC_LOCK(o);
 	oc = o->p_ucred;