From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Mon, 3 Oct 2016 18:35:51 +0000 (+0300)
Subject: keyctl: use printstr_ex for printing out buffer
X-Git-Tag: v4.14~6
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9f294b39f55daaffbfe55019455e2b5af74b28f7;p=strace

keyctl: use printstr_ex for printing out buffer

keyctl_read_key had subtle bug by treating out buffer in KEYCTL_READ
as NUL-terminated, which is not true.  We fix it by adding parameter to
keyctl_read_key signalising whether buffer is NUL-terminated and using
printstr_ex for printing (expectedly) NUL-terminated strings.

* keyctl.c (keyctl_read_key): Add has_nul parameter.  Do not use -1 as
string len.  Use printstr_ex for buffer output with user style depending
on has_nul value.
(SYS_FUNC(keyctl)): Specify has_nul parameter to keyctl_read_key
by comparing cmd value with KEYCTL_READ.
---

diff --git a/keyctl.c b/keyctl.c
index 536fa805..73f97662 100644
--- a/keyctl.c
+++ b/keyctl.c
@@ -108,7 +108,8 @@ keyctl_handle_key_key(struct tcb *tcp, key_serial_t id1, key_serial_t id2)
 }
 
 static void
-keyctl_read_key(struct tcb *tcp, key_serial_t id, long addr, long len)
+keyctl_read_key(struct tcb *tcp, key_serial_t id, long addr, long len,
+		bool has_nul)
 {
 	if (entering(tcp)) {
 		print_keyring_serial_number(id);
@@ -118,8 +119,9 @@ keyctl_read_key(struct tcb *tcp, key_serial_t id, long addr, long len)
 			printaddr(addr);
 		else {
 			long rval = tcp->u_rval > len ?
-				    len : (tcp->u_rval ? -1 : 0);
-			printstr(tcp, addr, rval);
+				    len : tcp->u_rval;
+			printstr_ex(tcp, addr, rval, has_nul ?
+				    QUOTE_OMIT_TRAILING_0 : 0);
 		}
 		tprintf(", %lu", len);
 	}
@@ -301,7 +303,8 @@ SYS_FUNC(keyctl)
 	case KEYCTL_READ:
 	case KEYCTL_GET_SECURITY:
 		keyctl_read_key(tcp, tcp->u_arg[1],
-				tcp->u_arg[2], tcp->u_arg[3]);
+				tcp->u_arg[2], tcp->u_arg[3],
+				cmd != KEYCTL_READ);
 		return 0;
 
 	case KEYCTL_SEARCH: