git: 175595ba6c52 - main - dl_iterate_phdr(3): do not return garbage for objects not using TLS

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=175595ba6c5253e395c028e792787dffd2875910

commit 175595ba6c5253e395c028e792787dffd2875910
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-10-25 15:35:21 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-10-25 17:33:46 +0000

    dl_iterate_phdr(3): do not return garbage for objects not using TLS
    
    For objects without a TLS segment, tlsindex is zero. tls_get_addr_slow()
    then reads dtv_slots[-1], which is dtv_size, and returns it as the TLS
    address. Set dlpi_tls_data to NULL for such objects instead.
    
    Fixes:  d36d68161517 ("rtld dl_iterate_phdr(): dlpi_tls_data is wrong")
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
---
 libexec/rtld-elf/rtld.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 877449296643..7ca5f9ada09f 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -4436,8 +4436,12 @@ rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
 	phdr_info->dlpi_phdr = obj->phdr;
 	phdr_info->dlpi_phnum = obj->phnum;
 	phdr_info->dlpi_tls_modid = obj->tlsindex;
-	phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(),
-	    obj->tlsindex, 0, true);
+	if (obj->tlsindex != 0) {
+		phdr_info->dlpi_tls_data = tls_get_addr_slow(_tcb_get(),
+		    obj->tlsindex, 0, true);
+	} else {
+		phdr_info->dlpi_tls_data = NULL;
+	}
 	phdr_info->dlpi_adds = obj_loads;
 	phdr_info->dlpi_subs = obj_loads - obj_count;
 }