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From: "Christian Göttsche" <cgzones@googlemail.com>
To: selinux@vger.kernel.org
Subject: [PATCH 09/11] libsemanage: support huge passwd entries
Date: Tue, 19 Dec 2023 17:09:31 +0100	[thread overview]
Message-ID: <20231219160943.334370-9-cgzones@googlemail.com> (raw)
In-Reply-To: <20231219160943.334370-1-cgzones@googlemail.com>

getpwnam_r(3) might return ERANGE in case the supplied buffer was too
short for the passwd entry.  Retry with a bigger buffer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
 libsemanage/src/genhomedircon.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/libsemanage/src/genhomedircon.c b/libsemanage/src/genhomedircon.c
index 66585987..ecb34fc7 100644
--- a/libsemanage/src/genhomedircon.c
+++ b/libsemanage/src/genhomedircon.c
@@ -985,9 +985,6 @@ static int add_user(genhomedircon_settings_t * s,
 		rbuflen = 1024;
 	else if (rbuflen <= 0)
 		goto cleanup;
-	rbuf = malloc(rbuflen);
-	if (rbuf == NULL)
-		goto cleanup;
 
 	if (user) {
 		prefix = semanage_user_get_prefix(user);
@@ -1005,7 +1002,17 @@ static int add_user(genhomedircon_settings_t * s,
 		homedir_role = prefix;
 	}
 
+retry:
+	rbuf = malloc(rbuflen);
+	if (rbuf == NULL)
+		goto cleanup;
+
 	retval = getpwnam_r(name, &pwstorage, rbuf, rbuflen, &pwent);
+	if (retval == ERANGE && rbuflen < LONG_MAX / 2) {
+		free(rbuf);
+		rbuflen *= 2;
+		goto retry;
+	}
 	if (retval != 0 || pwent == NULL) {
 		if (retval != 0 && retval != ENOENT) {
 			goto cleanup;
-- 
2.43.0


  parent reply	other threads:[~2023-12-19 16:10 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-19 16:09 [PATCH 01/11] libselinux/man: mention errno for regex compilation failure Christian Göttsche
2023-12-19 16:09 ` [PATCH 02/11] libselinux/man: sync selinux_check_securetty_context(3) Christian Göttsche
2023-12-19 16:09 ` [PATCH 03/11] libselinux/utils: free allocated resources Christian Göttsche
2023-12-19 16:09 ` [PATCH 04/11] libselinux/utils: improve compute_av output Christian Göttsche
2023-12-19 16:09 ` [PATCH 05/11] libselinux: align SELABEL_OPT_DIGEST usage with man page Christian Göttsche
2023-12-19 16:09 ` [PATCH 06/11] libselinux: fail selabel_open(3) on invalid option Christian Göttsche
2023-12-19 16:09 ` [PATCH 07/11] libselinux: use logging wrapper in getseuser(3) and get_default_context(3) family Christian Göttsche
2023-12-19 16:09 ` [PATCH 08/11] libselinux: support huge passwd/group entries Christian Göttsche
2023-12-19 16:09 ` Christian Göttsche [this message]
2023-12-19 16:09 ` [PATCH 10/11] libselinux: enable usage with pedantic UB sanitizers Christian Göttsche
2023-12-19 16:09 ` [PATCH 11/11] setfiles: avoid unsigned integer underflow Christian Göttsche
2024-01-05 19:15 ` [PATCH 01/11] libselinux/man: mention errno for regex compilation failure James Carter
2024-01-25 19:55   ` James Carter

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