git: cb31a266167c - main - ptrace: clear TDP_USERWR after transparent attach only on attach

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=cb31a266167c8bde3488fbdd6bf24c38b6f59977

commit cb31a266167c8bde3488fbdd6bf24c38b6f59977
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-05-11 01:12:30 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-05-13 19:40:03 +0000

    ptrace: clear TDP_USERWR after transparent attach only on attach
    
    The flag indicates that the modifying ptrace op was issued, and clearing
    it after transparent attach is needed to not leak the flag to later
    operations, since it is cleared on the syscall enter.
    
    But clearing it there unconditionally is too strong.  The clearing
    should be only done for attach situation.
    
    Reported by:    Alex S <iwtcex@gmail.com>
    Fixes:  99976934274de6fa19f049a0b6eac10856710f96
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D56928
---
 sys/kern/sys_process.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index dece6457a4bf..5effc6fbe2d7 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -1411,17 +1411,16 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 		 * register file or specifying the pc, make the thread
 		 * xstopped by waking it up.
 		 */
-		if ((td2->td_dbgflags & TDB_USERWR) != 0) {
-			if (pt_attach_transparent) {
-				thread_lock(td2);
-				if (TD_ON_SLEEPQ(td2) &&
-				    (td2->td_flags & TDF_SINTR) != 0) {
-					sleepq_abort(td2, EINTR);
-				} else {
-					thread_unlock(td2);
-				}
+		if ((td2->td_dbgflags & TDB_USERWR) != 0 &&
+		    pt_attach_transparent) {
+			thread_lock(td2);
+			if (TD_ON_SLEEPQ(td2) &&
+			    (td2->td_flags & TDF_SINTR) != 0) {
+				td2->td_dbgflags &= ~TDB_USERWR;
+				sleepq_abort(td2, EINTR);
+			} else {
+				thread_unlock(td2);
 			}
-			td2->td_dbgflags &= ~TDB_USERWR;
 		}
 
 		/*