* [PATCH v2] lsm:fix a missing-check bug in smack_sb_eat_lsm_opts()
@ 2021-04-16 10:12 Zhongjun Tan
0 siblings, 0 replies; only message in thread
From: Zhongjun Tan @ 2021-04-16 10:12 UTC (permalink / raw)
To: casey, jmorris, serge; +Cc: linux-security-module, linux-kernel, Zhongjun Tan
From: Zhongjun Tan <tanzhongjun@yulong.com>
In smack_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: Zhongjun Tan <tanzhongjun@yulong.com>
---
v2:fix brace error
security/smack/smack_lsm.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 223a6da..1e4c66f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -696,10 +696,11 @@ static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
{
char *from = options, *to = options;
bool first = true;
+ int rc;
while (1) {
char *next = strchr(from, ',');
- int token, len, rc;
+ int token, len;
char *arg = NULL;
if (next)
@@ -710,13 +711,14 @@ static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
token = match_opt_prefix(from, len, &arg);
if (token != Opt_error) {
arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
+ if (!arg) {
+ rc = -ENOMEM;
+ goto free_mnt_opts;
+ }
rc = smack_add_opt(token, arg, mnt_opts);
if (unlikely(rc)) {
kfree(arg);
- if (*mnt_opts)
- smack_free_mnt_opts(*mnt_opts);
- *mnt_opts = NULL;
- return rc;
+ goto free_mnt_opts;
}
} else {
if (!first) { // copy with preceding comma
@@ -734,6 +736,13 @@ static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
}
*to = '\0';
return 0;
+
+free_mnt_opts:
+ if (*mnt_opts) {
+ smack_free_mnt_opts(*mnt_opts);
+ *mnt_opts = NULL;
+ }
+ return rc;
}
/**
--
1.9.1
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