From: Steve Lawrence <slawrence@tresys.com>
To: Petr Lautrbach <plautrba@redhat.com>, <selinux@tycho.nsa.gov>
Subject: Re: [PATCH] libselinux: Verify context input to funtions to make sure the context field is not null.
Date: Thu, 17 Dec 2015 08:55:32 -0500 [thread overview]
Message-ID: <5672BED4.6000802@tresys.com> (raw)
In-Reply-To: <1449694065-26728-1-git-send-email-plautrba@redhat.com>
I believe this patch, or something similar, was sent to the list in the
past and was rejected. Passing in a NULL context is considered invalid
use, similar to strdup/strcmp/etc. and is a bug in the calling process.
On 12/09/2015 03:47 PM, Petr Lautrbach wrote:
> From: Dan Walsh <dwalsh@redhat.com>
>
> Return errno EINVAL, to prevent segfault.
>
> Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
> ---
> libselinux/src/avc_sidtab.c | 5 +++++
> libselinux/src/canonicalize_context.c | 5 +++++
> libselinux/src/check_context.c | 5 +++++
> libselinux/src/compute_av.c | 5 +++++
> libselinux/src/compute_create.c | 5 +++++
> libselinux/src/compute_member.c | 5 +++++
> libselinux/src/compute_relabel.c | 5 +++++
> libselinux/src/compute_user.c | 5 +++++
> libselinux/src/fsetfilecon.c | 8 ++++++--
> libselinux/src/lsetfilecon.c | 9 +++++++--
> libselinux/src/setfilecon.c | 8 ++++++--
> 11 files changed, 59 insertions(+), 6 deletions(-)
>
> diff --git a/libselinux/src/avc_sidtab.c b/libselinux/src/avc_sidtab.c
> index 9669264..a46cfa7 100644
> --- a/libselinux/src/avc_sidtab.c
> +++ b/libselinux/src/avc_sidtab.c
> @@ -81,6 +81,11 @@ sidtab_context_to_sid(struct sidtab *s,
> int hvalue, rc = 0;
> struct sidtab_node *cur;
>
> + if (! ctx) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> *sid = NULL;
> hvalue = sidtab_hash(ctx);
>
> diff --git a/libselinux/src/canonicalize_context.c b/libselinux/src/canonicalize_context.c
> index 7cf3139..9d8dc86 100644
> --- a/libselinux/src/canonicalize_context.c
> +++ b/libselinux/src/canonicalize_context.c
> @@ -17,6 +17,11 @@ int security_canonicalize_context_raw(const char * con,
> size_t size;
> int fd, ret;
>
> + if (! con) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> if (!selinux_mnt) {
> errno = ENOENT;
> return -1;
> diff --git a/libselinux/src/check_context.c b/libselinux/src/check_context.c
> index 52063fa..9637dd7 100644
> --- a/libselinux/src/check_context.c
> +++ b/libselinux/src/check_context.c
> @@ -14,6 +14,11 @@ int security_check_context_raw(const char * con)
> char path[PATH_MAX];
> int fd, ret;
>
> + if (! con) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> if (!selinux_mnt) {
> errno = ENOENT;
> return -1;
> diff --git a/libselinux/src/compute_av.c b/libselinux/src/compute_av.c
> index 937e5c3..e67b3d3 100644
> --- a/libselinux/src/compute_av.c
> +++ b/libselinux/src/compute_av.c
> @@ -26,6 +26,11 @@ int security_compute_av_flags_raw(const char * scon,
> return -1;
> }
>
> + if ((! scon) || (! tcon)) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> snprintf(path, sizeof path, "%s/access", selinux_mnt);
> fd = open(path, O_RDWR);
> if (fd < 0)
> diff --git a/libselinux/src/compute_create.c b/libselinux/src/compute_create.c
> index 9559d42..7de721a 100644
> --- a/libselinux/src/compute_create.c
> +++ b/libselinux/src/compute_create.c
> @@ -64,6 +64,11 @@ int security_compute_create_name_raw(const char * scon,
> return -1;
> }
>
> + if ((! scon) || (! tcon)) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> snprintf(path, sizeof path, "%s/create", selinux_mnt);
> fd = open(path, O_RDWR);
> if (fd < 0)
> diff --git a/libselinux/src/compute_member.c b/libselinux/src/compute_member.c
> index 1fc7e41..4ff2173 100644
> --- a/libselinux/src/compute_member.c
> +++ b/libselinux/src/compute_member.c
> @@ -25,6 +25,11 @@ int security_compute_member_raw(const char * scon,
> return -1;
> }
>
> + if ((! scon) || (! tcon)) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> snprintf(path, sizeof path, "%s/member", selinux_mnt);
> fd = open(path, O_RDWR);
> if (fd < 0)
> diff --git a/libselinux/src/compute_relabel.c b/libselinux/src/compute_relabel.c
> index 4615aee..6a37acf 100644
> --- a/libselinux/src/compute_relabel.c
> +++ b/libselinux/src/compute_relabel.c
> @@ -25,6 +25,11 @@ int security_compute_relabel_raw(const char * scon,
> return -1;
> }
>
> + if ((! scon) || (! tcon)) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> snprintf(path, sizeof path, "%s/relabel", selinux_mnt);
> fd = open(path, O_RDWR);
> if (fd < 0)
> diff --git a/libselinux/src/compute_user.c b/libselinux/src/compute_user.c
> index b37c5d3..3737c28 100644
> --- a/libselinux/src/compute_user.c
> +++ b/libselinux/src/compute_user.c
> @@ -24,6 +24,11 @@ int security_compute_user_raw(const char * scon,
> return -1;
> }
>
> + if (! scon) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> snprintf(path, sizeof path, "%s/user", selinux_mnt);
> fd = open(path, O_RDWR);
> if (fd < 0)
> diff --git a/libselinux/src/fsetfilecon.c b/libselinux/src/fsetfilecon.c
> index 52707d0..83c138e 100644
> --- a/libselinux/src/fsetfilecon.c
> +++ b/libselinux/src/fsetfilecon.c
> @@ -9,8 +9,12 @@
>
> int fsetfilecon_raw(int fd, const char * context)
> {
> - int rc = fsetxattr(fd, XATTR_NAME_SELINUX, context, strlen(context) + 1,
> - 0);
> + int rc;
> + if (! context) {
> + errno = EINVAL;
> + return -1;
> + }
> + rc = fsetxattr(fd, XATTR_NAME_SELINUX, context, strlen(context) + 1, 0);
> if (rc < 0 && errno == ENOTSUP) {
> char * ccontext = NULL;
> int err = errno;
> diff --git a/libselinux/src/lsetfilecon.c b/libselinux/src/lsetfilecon.c
> index 1d3b28a..278e42a 100644
> --- a/libselinux/src/lsetfilecon.c
> +++ b/libselinux/src/lsetfilecon.c
> @@ -9,8 +9,13 @@
>
> int lsetfilecon_raw(const char *path, const char * context)
> {
> - int rc = lsetxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1,
> - 0);
> + int rc;
> + if (! context) {
> + errno = EINVAL;
> + return -1;
> + }
> +
> + rc = lsetxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1, 0);
> if (rc < 0 && errno == ENOTSUP) {
> char * ccontext = NULL;
> int err = errno;
> diff --git a/libselinux/src/setfilecon.c b/libselinux/src/setfilecon.c
> index d05969c..dddce3c 100644
> --- a/libselinux/src/setfilecon.c
> +++ b/libselinux/src/setfilecon.c
> @@ -9,8 +9,12 @@
>
> int setfilecon_raw(const char *path, const char * context)
> {
> - int rc = setxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1,
> - 0);
> + int rc;
> + if (! context) {
> + errno = EINVAL;
> + return -1;
> + }
> + rc = setxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1, 0);
> if (rc < 0 && errno == ENOTSUP) {
> char * ccontext = NULL;
> int err = errno;
>
next prev parent reply other threads:[~2015-12-17 13:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-09 20:47 [PATCH] libselinux: Verify context input to funtions to make sure the context field is not null Petr Lautrbach
2015-12-17 13:55 ` Steve Lawrence [this message]
2015-12-17 14:06 ` Petr Lautrbach
2015-12-17 14:22 ` Joshua Brindle
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