From: Gen Zhang <blackgod016574@gmail.com>
To: paul@paul-moore.com, sds@tycho.nsa.gov, eparis@parisplace.org
Cc: selinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v4] selinux: lsm: fix a missing-check bug in selinux_sb_eat_lsm_o pts()
Date: Thu, 6 Jun 2019 16:55:24 +0800 [thread overview]
Message-ID: <20190606085524.GA21119@zhanggen-UX430UQ> (raw)
In selinux_sb_eat_lsm_opts(), 'arg' is allocated by kmemdup_nul(). It
returns NULL when fails. So 'arg' should be checked. And 'mnt_opts'
should be freed when error.
Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Fixes: 99dbbb593fe6 ("selinux: rewrite selinux_sb_eat_lsm_opts()")
---
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3ec702c..13479cd 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2616,10 +2616,11 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
char *from = options;
char *to = options;
bool first = true;
+ int rc;
while (1) {
int len = opt_len(from);
- int token, rc;
+ int token;
char *arg = NULL;
token = match_opt_prefix(from, len, &arg);
@@ -2635,15 +2636,15 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
*q++ = c;
}
arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
+ if (!arg) {
+ rc = -ENOMEM;
+ goto free_opt;
+ }
}
rc = selinux_add_opt(token, arg, mnt_opts);
if (unlikely(rc)) {
kfree(arg);
- if (*mnt_opts) {
- selinux_free_mnt_opts(*mnt_opts);
- *mnt_opts = NULL;
- }
- return rc;
+ goto free_opt;
}
} else {
if (!first) { // copy with preceding comma
@@ -2661,6 +2662,12 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
}
*to = '\0';
return 0;
+free_opt:
+ if (*mnt_opts) {
+ selinux_free_mnt_opts(*mnt_opts);
+ *mnt_opts = NULL;
+ }
+ return rc;
}
static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
next reply other threads:[~2019-06-06 8:55 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-06 8:55 Gen Zhang [this message]
2019-06-07 8:41 ` [PATCH v4] selinux: lsm: fix a missing-check bug in selinux_sb_eat_lsm_o pts() Ondrej Mosnacek
2019-06-10 20:20 ` Paul Moore
2019-06-11 3:05 ` Gen Zhang
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