From: Steve Dickson <steved@redhat.com>
To: "Bogdan-Cristian Tătăroiu" <b.tataroiu@gmail.com>,
linux-nfs@vger.kernel.org
Subject: Re: [PATCH] Add guards around [nfsidmap] usages of [sysconf].
Date: Mon, 17 Jun 2024 14:51:48 -0500 [thread overview]
Message-ID: <d7165359-a031-456e-bfae-a45d0aed5d80@redhat.com> (raw)
In-Reply-To: <20240530071725.70043-1-b.tataroiu@gmail.com>
On 5/30/24 2:17 AM, Bogdan-Cristian Tătăroiu wrote:
> sysconf(_SC_GETPW_R_SIZE_MAX) and sysconf(_SC_GETGR_R_SIZE_MAX)
> return -1 on musl, which causes either segmentation faults or ENOMEM
> errors.
Actually sysconf() returns EINVAL not -1 since the return
value is a size_t (unsigned long). So I needed to change
size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
if (buflen == EINVAL) <<< this from -1 to EINVAL
buflen = 16384;
return buflen;
Good with that? Will this work with musl?
steved.
>
> Replace all usages of sysconf with dedicated methods that guard against
> a result of -1.
>
> Signed-off-by: Bogdan-Cristian Tătăroiu <b.tataroiu@gmail.com>
> ---
> support/nfsidmap/gums.c | 4 ++--
> support/nfsidmap/libnfsidmap.c | 4 ++--
> support/nfsidmap/nfsidmap_common.c | 16 ++++++++++++++++
> support/nfsidmap/nfsidmap_private.h | 2 ++
> support/nfsidmap/nss.c | 8 ++++----
> support/nfsidmap/regex.c | 9 +++++----
> support/nfsidmap/static.c | 5 +++--
> 7 files changed, 34 insertions(+), 14 deletions(-)
>
> diff --git a/support/nfsidmap/gums.c b/support/nfsidmap/gums.c
> index 1d6eb318..e94a4c50 100644
> --- a/support/nfsidmap/gums.c
> +++ b/support/nfsidmap/gums.c
> @@ -475,7 +475,7 @@ static int translate_to_uid(char *local_uid, uid_t *uid, uid_t *gid)
> int ret = -1;
> struct passwd *pw = NULL;
> struct pwbuf *buf = NULL;
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
>
> buf = malloc(sizeof(*buf) + buflen);
> if (buf == NULL)
> @@ -501,7 +501,7 @@ static int translate_to_gid(char *local_gid, uid_t *gid)
> struct group *gr = NULL;
> struct group grbuf;
> char *buf = NULL;
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> int ret = -1;
>
> do {
> diff --git a/support/nfsidmap/libnfsidmap.c b/support/nfsidmap/libnfsidmap.c
> index f8c36480..e1475879 100644
> --- a/support/nfsidmap/libnfsidmap.c
> +++ b/support/nfsidmap/libnfsidmap.c
> @@ -457,7 +457,7 @@ int nfs4_init_name_mapping(char *conffile)
>
> nobody_user = conf_get_str("Mapping", "Nobody-User");
> if (nobody_user) {
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
> struct passwd *buf;
> struct passwd *pw = NULL;
> int err;
> @@ -478,7 +478,7 @@ int nfs4_init_name_mapping(char *conffile)
>
> nobody_group = conf_get_str("Mapping", "Nobody-Group");
> if (nobody_group) {
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> struct group *buf;
> struct group *gr = NULL;
> int err;
> diff --git a/support/nfsidmap/nfsidmap_common.c b/support/nfsidmap/nfsidmap_common.c
> index 4d2cb14f..310c68f0 100644
> --- a/support/nfsidmap/nfsidmap_common.c
> +++ b/support/nfsidmap/nfsidmap_common.c
> @@ -116,3 +116,19 @@ int get_reformat_group(void)
>
> return reformat_group;
> }
> +
> +size_t get_pwnam_buflen(void)
> +{
> + size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + if (buflen == -1)
> + buflen = 16384;
> + return buflen;
> +}
> +
> +size_t get_grnam_buflen(void)
> +{
> + size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + if (buflen == -1)
> + buflen = 16384;
> + return buflen;
> +}
> diff --git a/support/nfsidmap/nfsidmap_private.h b/support/nfsidmap/nfsidmap_private.h
> index a5cb6dda..234ca9d4 100644
> --- a/support/nfsidmap/nfsidmap_private.h
> +++ b/support/nfsidmap/nfsidmap_private.h
> @@ -40,6 +40,8 @@ struct conf_list *get_local_realms(void);
> void free_local_realms(void);
> int get_nostrip(void);
> int get_reformat_group(void);
> +size_t get_pwnam_buflen(void);
> +size_t get_grnam_buflen(void);
>
> typedef enum {
> IDTYPE_USER = 1,
> diff --git a/support/nfsidmap/nss.c b/support/nfsidmap/nss.c
> index 0f43076e..3fc045dc 100644
> --- a/support/nfsidmap/nss.c
> +++ b/support/nfsidmap/nss.c
> @@ -91,7 +91,7 @@ static int nss_uid_to_name(uid_t uid, char *domain, char *name, size_t len)
> struct passwd *pw = NULL;
> struct passwd pwbuf;
> char *buf;
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
> int err = -ENOMEM;
>
> buf = malloc(buflen);
> @@ -119,7 +119,7 @@ static int nss_gid_to_name(gid_t gid, char *domain, char *name, size_t len)
> struct group *gr = NULL;
> struct group grbuf;
> char *buf;
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> int err;
>
> if (domain == NULL)
> @@ -192,7 +192,7 @@ static struct passwd *nss_getpwnam(const char *name, const char *domain,
> {
> struct passwd *pw;
> struct pwbuf *buf;
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
> char *localname;
> int err = ENOMEM;
>
> @@ -301,7 +301,7 @@ static int _nss_name_to_gid(char *name, gid_t *gid, int dostrip)
> struct group *gr = NULL;
> struct group grbuf;
> char *buf, *domain;
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> int err = -EINVAL;
> char *localname = NULL;
> char *ref_name = NULL;
> diff --git a/support/nfsidmap/regex.c b/support/nfsidmap/regex.c
> index 8424179f..ea094b95 100644
> --- a/support/nfsidmap/regex.c
> +++ b/support/nfsidmap/regex.c
> @@ -46,6 +46,7 @@
>
> #include "nfsidmap.h"
> #include "nfsidmap_plugin.h"
> +#include "nfsidmap_private.h"
>
> #define CONFIG_GET_STRING nfsidmap_config_get
> extern const char *nfsidmap_config_get(const char *, const char *);
> @@ -95,7 +96,7 @@ static struct passwd *regex_getpwnam(const char *name, const char *UNUSED(domain
> {
> struct passwd *pw;
> struct pwbuf *buf;
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
> char *localname;
> size_t namelen;
> int err;
> @@ -175,7 +176,7 @@ static struct group *regex_getgrnam(const char *name, const char *UNUSED(domain)
> {
> struct group *gr;
> struct grbuf *buf;
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> char *localgroup;
> char *groupname;
> size_t namelen;
> @@ -366,7 +367,7 @@ static int regex_uid_to_name(uid_t uid, char *domain, char *name, size_t len)
> struct passwd *pw = NULL;
> struct passwd pwbuf;
> char *buf;
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
> int err = -ENOMEM;
>
> buf = malloc(buflen);
> @@ -392,7 +393,7 @@ static int regex_gid_to_name(gid_t gid, char *UNUSED(domain), char *name, size_t
> struct group grbuf;
> char *buf;
> const char *name_prefix;
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> int err;
> char * groupname = NULL;
>
> diff --git a/support/nfsidmap/static.c b/support/nfsidmap/static.c
> index 8ac4a398..395cac06 100644
> --- a/support/nfsidmap/static.c
> +++ b/support/nfsidmap/static.c
> @@ -44,6 +44,7 @@
> #include "conffile.h"
> #include "nfsidmap.h"
> #include "nfsidmap_plugin.h"
> +#include "nfsidmap_private.h"
>
> /*
> * Static Translation Methods
> @@ -98,7 +99,7 @@ static struct passwd *static_getpwnam(const char *name,
> {
> struct passwd *pw;
> struct pwbuf *buf;
> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> + size_t buflen = get_pwnam_buflen();
> char *localname;
> int err;
>
> @@ -149,7 +150,7 @@ static struct group *static_getgrnam(const char *name,
> {
> struct group *gr;
> struct grbuf *buf;
> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> + size_t buflen = get_grnam_buflen();
> char *localgroup;
> int err;
>
next prev parent reply other threads:[~2024-06-17 19:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-30 7:17 [PATCH] Add guards around [nfsidmap] usages of [sysconf] Bogdan-Cristian Tătăroiu
2024-06-17 19:51 ` Steve Dickson [this message]
2024-11-09 18:25 ` Steve Dickson
2024-11-30 12:32 ` Bogdan-Cristian Tătăroiu
2024-11-30 14:20 ` Steve Dickson
2024-12-01 9:21 ` Bogdan-Cristian Tătăroiu
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