* [PATCH] libselinux: set errno to EBADF on O_PATH emulation failure
@ 2022-07-06 10:47 Christian Göttsche
2022-07-06 11:38 ` [PATCH v2] libselinux: set errno to EBADF on O_PATH emulation ENOENT failure Christian Göttsche
0 siblings, 1 reply; 4+ messages in thread
From: Christian Göttsche @ 2022-07-06 10:47 UTC (permalink / raw)
To: selinux
When the O_PATH emulation fails override the errno value to EBADF
instead of retaining the one from getxattr(2)/setxattr(2).
For example in the case of no procfs being mounted, e.g. inside of a
chroot, getxattr(2)/setxattr(2) fail with ENOENT. This is confusing to
the caller as it seems the target of the operation does not exist, which
is not the case:
setfiles: Could not set context for /: No such file or directory
Fixes: a782abf2 ("libselinux: emulate O_PATH support in fgetfilecon/fsetfilecon")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
libselinux/src/fgetfilecon.c | 8 +++++---
libselinux/src/fsetfilecon.c | 8 +++++---
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/libselinux/src/fgetfilecon.c b/libselinux/src/fgetfilecon.c
index baf38ec1..4c440df3 100644
--- a/libselinux/src/fgetfilecon.c
+++ b/libselinux/src/fgetfilecon.c
@@ -10,7 +10,7 @@
static ssize_t fgetxattr_wrapper(int fd, const char *name, void *value, size_t size) {
char buf[40];
- int fd_flag, saved_errno = errno;
+ int fd_flag;
ssize_t ret;
ret = fgetxattr(fd, name, value, size);
@@ -25,8 +25,10 @@ static ssize_t fgetxattr_wrapper(int fd, const char *name, void *value, size_t s
}
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
- errno = saved_errno;
- return getxattr(buf, name, value, size);
+ ret = getxattr(buf, name, value, size);
+ if (ret < 0)
+ errno = EBADF;
+ return ret;
}
int fgetfilecon_raw(int fd, char ** context)
diff --git a/libselinux/src/fsetfilecon.c b/libselinux/src/fsetfilecon.c
index be821c7a..374dc627 100644
--- a/libselinux/src/fsetfilecon.c
+++ b/libselinux/src/fsetfilecon.c
@@ -10,7 +10,7 @@
static int fsetxattr_wrapper(int fd, const char* name, const void* value, size_t size, int flags) {
char buf[40];
- int rc, fd_flag, saved_errno = errno;
+ int rc, fd_flag;
rc = fsetxattr(fd, name, value, size, flags);
if (rc == 0 || errno != EBADF)
@@ -24,8 +24,10 @@ static int fsetxattr_wrapper(int fd, const char* name, const void* value, size_t
}
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
- errno = saved_errno;
- return setxattr(buf, name, value, size, flags);
+ rc = setxattr(buf, name, value, size, flags);
+ if (rc < 0)
+ errno = EBADF;
+ return rc;
}
int fsetfilecon_raw(int fd, const char * context)
--
2.36.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v2] libselinux: set errno to EBADF on O_PATH emulation ENOENT failure
2022-07-06 10:47 [PATCH] libselinux: set errno to EBADF on O_PATH emulation failure Christian Göttsche
@ 2022-07-06 11:38 ` Christian Göttsche
2022-07-07 17:44 ` James Carter
0 siblings, 1 reply; 4+ messages in thread
From: Christian Göttsche @ 2022-07-06 11:38 UTC (permalink / raw)
To: selinux
When the O_PATH emulation fails due to getxattr(2)/setxattr(2) failing
with ENOENT, e.g. because no procfs being available, override the errno
value to EBADF. This avoids confusion to the caller as it would suggest
the target of the operation does not exist, which is not the case:
setfiles: Could not set context for /: No such file or directory
Fixes: a782abf2 ("libselinux: emulate O_PATH support in fgetfilecon/fsetfilecon")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
v2:
only override errno on ENOENT
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
libselinux/src/fgetfilecon.c | 5 ++++-
libselinux/src/fsetfilecon.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/libselinux/src/fgetfilecon.c b/libselinux/src/fgetfilecon.c
index baf38ec1..d7051171 100644
--- a/libselinux/src/fgetfilecon.c
+++ b/libselinux/src/fgetfilecon.c
@@ -26,7 +26,10 @@ static ssize_t fgetxattr_wrapper(int fd, const char *name, void *value, size_t s
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
errno = saved_errno;
- return getxattr(buf, name, value, size);
+ ret = getxattr(buf, name, value, size);
+ if (ret < 0 && errno == ENOENT)
+ errno = EBADF;
+ return ret;
}
int fgetfilecon_raw(int fd, char ** context)
diff --git a/libselinux/src/fsetfilecon.c b/libselinux/src/fsetfilecon.c
index be821c7a..19ea15b7 100644
--- a/libselinux/src/fsetfilecon.c
+++ b/libselinux/src/fsetfilecon.c
@@ -25,7 +25,10 @@ static int fsetxattr_wrapper(int fd, const char* name, const void* value, size_t
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
errno = saved_errno;
- return setxattr(buf, name, value, size, flags);
+ rc = setxattr(buf, name, value, size, flags);
+ if (rc < 0 && errno == ENOENT)
+ errno = EBADF;
+ return rc;
}
int fsetfilecon_raw(int fd, const char * context)
--
2.36.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] libselinux: set errno to EBADF on O_PATH emulation ENOENT failure
2022-07-06 11:38 ` [PATCH v2] libselinux: set errno to EBADF on O_PATH emulation ENOENT failure Christian Göttsche
@ 2022-07-07 17:44 ` James Carter
2022-08-09 15:18 ` James Carter
0 siblings, 1 reply; 4+ messages in thread
From: James Carter @ 2022-07-07 17:44 UTC (permalink / raw)
To: Christian Göttsche; +Cc: SElinux list
On Wed, Jul 6, 2022 at 7:42 AM Christian Göttsche
<cgzones@googlemail.com> wrote:
>
> When the O_PATH emulation fails due to getxattr(2)/setxattr(2) failing
> with ENOENT, e.g. because no procfs being available, override the errno
> value to EBADF. This avoids confusion to the caller as it would suggest
> the target of the operation does not exist, which is not the case:
>
> setfiles: Could not set context for /: No such file or directory
>
> Fixes: a782abf2 ("libselinux: emulate O_PATH support in fgetfilecon/fsetfilecon")
> Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: James Carter <jwcart2@gmail.com>
> ---
> v2:
> only override errno on ENOENT
> Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
> ---
> libselinux/src/fgetfilecon.c | 5 ++++-
> libselinux/src/fsetfilecon.c | 5 ++++-
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/libselinux/src/fgetfilecon.c b/libselinux/src/fgetfilecon.c
> index baf38ec1..d7051171 100644
> --- a/libselinux/src/fgetfilecon.c
> +++ b/libselinux/src/fgetfilecon.c
> @@ -26,7 +26,10 @@ static ssize_t fgetxattr_wrapper(int fd, const char *name, void *value, size_t s
>
> snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
> errno = saved_errno;
> - return getxattr(buf, name, value, size);
> + ret = getxattr(buf, name, value, size);
> + if (ret < 0 && errno == ENOENT)
> + errno = EBADF;
> + return ret;
> }
>
> int fgetfilecon_raw(int fd, char ** context)
> diff --git a/libselinux/src/fsetfilecon.c b/libselinux/src/fsetfilecon.c
> index be821c7a..19ea15b7 100644
> --- a/libselinux/src/fsetfilecon.c
> +++ b/libselinux/src/fsetfilecon.c
> @@ -25,7 +25,10 @@ static int fsetxattr_wrapper(int fd, const char* name, const void* value, size_t
>
> snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
> errno = saved_errno;
> - return setxattr(buf, name, value, size, flags);
> + rc = setxattr(buf, name, value, size, flags);
> + if (rc < 0 && errno == ENOENT)
> + errno = EBADF;
> + return rc;
> }
>
> int fsetfilecon_raw(int fd, const char * context)
> --
> 2.36.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] libselinux: set errno to EBADF on O_PATH emulation ENOENT failure
2022-07-07 17:44 ` James Carter
@ 2022-08-09 15:18 ` James Carter
0 siblings, 0 replies; 4+ messages in thread
From: James Carter @ 2022-08-09 15:18 UTC (permalink / raw)
To: Christian Göttsche; +Cc: SElinux list
On Thu, Jul 7, 2022 at 1:44 PM James Carter <jwcart2@gmail.com> wrote:
>
> On Wed, Jul 6, 2022 at 7:42 AM Christian Göttsche
> <cgzones@googlemail.com> wrote:
> >
> > When the O_PATH emulation fails due to getxattr(2)/setxattr(2) failing
> > with ENOENT, e.g. because no procfs being available, override the errno
> > value to EBADF. This avoids confusion to the caller as it would suggest
> > the target of the operation does not exist, which is not the case:
> >
> > setfiles: Could not set context for /: No such file or directory
> >
> > Fixes: a782abf2 ("libselinux: emulate O_PATH support in fgetfilecon/fsetfilecon")
> > Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
>
> Acked-by: James Carter <jwcart2@gmail.com>
>
Merged.
Thanks,
Jim
> > ---
> > v2:
> > only override errno on ENOENT
> > Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
> > ---
> > libselinux/src/fgetfilecon.c | 5 ++++-
> > libselinux/src/fsetfilecon.c | 5 ++++-
> > 2 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/libselinux/src/fgetfilecon.c b/libselinux/src/fgetfilecon.c
> > index baf38ec1..d7051171 100644
> > --- a/libselinux/src/fgetfilecon.c
> > +++ b/libselinux/src/fgetfilecon.c
> > @@ -26,7 +26,10 @@ static ssize_t fgetxattr_wrapper(int fd, const char *name, void *value, size_t s
> >
> > snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
> > errno = saved_errno;
> > - return getxattr(buf, name, value, size);
> > + ret = getxattr(buf, name, value, size);
> > + if (ret < 0 && errno == ENOENT)
> > + errno = EBADF;
> > + return ret;
> > }
> >
> > int fgetfilecon_raw(int fd, char ** context)
> > diff --git a/libselinux/src/fsetfilecon.c b/libselinux/src/fsetfilecon.c
> > index be821c7a..19ea15b7 100644
> > --- a/libselinux/src/fsetfilecon.c
> > +++ b/libselinux/src/fsetfilecon.c
> > @@ -25,7 +25,10 @@ static int fsetxattr_wrapper(int fd, const char* name, const void* value, size_t
> >
> > snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
> > errno = saved_errno;
> > - return setxattr(buf, name, value, size, flags);
> > + rc = setxattr(buf, name, value, size, flags);
> > + if (rc < 0 && errno == ENOENT)
> > + errno = EBADF;
> > + return rc;
> > }
> >
> > int fsetfilecon_raw(int fd, const char * context)
> > --
> > 2.36.1
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-08-09 15:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-07-06 10:47 [PATCH] libselinux: set errno to EBADF on O_PATH emulation failure Christian Göttsche
2022-07-06 11:38 ` [PATCH v2] libselinux: set errno to EBADF on O_PATH emulation ENOENT failure Christian Göttsche
2022-07-07 17:44 ` James Carter
2022-08-09 15:18 ` James Carter
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