* [PATCH] lsm:fix a missing-check bug in smack_sb_eat_lsm_opts()
@ 2021-04-16 9:53 Zhongjun Tan
2021-04-16 13:36 ` Al Viro
0 siblings, 1 reply; 3+ messages in thread
From: Zhongjun Tan @ 2021-04-16 9:53 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>
---
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..0d5439f 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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] lsm:fix a missing-check bug in smack_sb_eat_lsm_opts()
2021-04-16 9:53 [PATCH] lsm:fix a missing-check bug in smack_sb_eat_lsm_opts() Zhongjun Tan
@ 2021-04-16 13:36 ` Al Viro
2021-04-19 2:58 ` Zhongjun Tan
0 siblings, 1 reply; 3+ messages in thread
From: Al Viro @ 2021-04-16 13:36 UTC (permalink / raw)
To: Zhongjun Tan
Cc: casey, jmorris, serge, linux-security-module, linux-kernel, Zhongjun Tan
On Fri, Apr 16, 2021 at 05:53:03PM +0800, Zhongjun Tan wrote:
> @@ -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 (arg)
rc = smack_add_opt(token, arg, mnt_opts);
else
rc = -ENOMEM;
and no other changes are needed anywhere...
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] lsm:fix a missing-check bug in smack_sb_eat_lsm_opts()
2021-04-16 13:36 ` Al Viro
@ 2021-04-19 2:58 ` Zhongjun Tan
0 siblings, 0 replies; 3+ messages in thread
From: Zhongjun Tan @ 2021-04-19 2:58 UTC (permalink / raw)
To: Al Viro
Cc: casey, jmorris, serge, linux-security-module, linux-kernel, Zhongjun Tan
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=GB18030, Size: 719 bytes --]
On Fri, 16 Apr 2021 13:36:01 +0000
Al Viro <viro@zeniv.linux.org.uk> wrote:
> On Fri, Apr 16, 2021 at 05:53:03PM +0800, 0„2Zhongjun Tan wrote:
>
> > @@ -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 (arg)
> rc = smack_add_opt(token, arg,
> mnt_opts); else
> rc = -ENOMEM;
>
> and no other changes are needed anywhere...
update patch v3 , just four codes and no other changes are needed.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-04-19 2:59 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-16 9:53 [PATCH] lsm:fix a missing-check bug in smack_sb_eat_lsm_opts() Zhongjun Tan
2021-04-16 13:36 ` Al Viro
2021-04-19 2:58 ` Zhongjun Tan
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).