diff mbox

[PATCHv3,man-pages,3/3] open.2: describe O_BENEATH flag

Message ID 1425909612-28034-4-git-send-email-drysdale@google.com (mailing list archive)
State New, archived
Headers show

Commit Message

David Drysdale March 9, 2015, 2 p.m. UTC 
Signed-off-by: David Drysdale <drysdale@google.com>
---
 man2/open.2 | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

--
2.2.0.rc0.207.ga3a616c
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Comments

Michael Kerrisk (man-pages) March 9, 2015, 2:32 p.m. UTC | #1 
On 03/09/2015 03:00 PM, David Drysdale wrote:
> Signed-off-by: David Drysdale <drysdale@google.com>

Hi David,

The text looks good insofar as it goes. But, it would be helpful
to have sentence or to that explains why this flag exists.
Could you add that, please?

Thanks,

Michael

> ---
>  man2/open.2 | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> 
> diff --git a/man2/open.2 b/man2/open.2
> index 956531b24b26..be40dd7710df 100644
> --- a/man2/open.2
> +++ b/man2/open.2
> @@ -716,6 +716,31 @@ XFS support was added
>  .\" commit ab29743117f9f4c22ac44c13c1647fb24fb2bafe
>  in Linux 3.15.
>  .TP
> +.B O_BENEATH " (since Linux 3.??)"
> +Ensure that the
> +.I pathname
> +is beneath the current working directory (for
> +.BR open (2))
> +or the
> +.I dirfd
> +(for
> +.BR openat (2)).
> +If the
> +.I pathname
> +is absolute or contains a path component of "..", the
> +.BR open ()
> +fails with the error
> +.BR EPERM.
> +This occurs even if ".." path component would not actually
> +escape the original directory; for example, a
> +.I pathname
> +of "subdir/../filename" would be rejected.
> +Path components that are symbolic links to absolute paths, or that are
> +relative paths containing a ".." component, will also cause the
> +.BR open ()
> +operation to fail with the error
> +.BR EPERM.
> +.TP
>  .B O_TRUNC
>  If the file already exists and is a regular file and the access mode allows
>  writing (i.e., is
> @@ -984,6 +1009,13 @@ did not match the owner of the file and the caller was not privileged
>  The operation was prevented by a file seal; see
>  .BR fcntl (2).
>  .TP
> +.B EPERM
> +The
> +.B O_BENEATH
> +flag was specified and the
> +.I pathname
> +was not beneath the relevant directory.
> +.TP
>  .B EROFS
>  .I pathname
>  refers to a file on a read-only filesystem and write access was
> --
> 2.2.0.rc0.207.ga3a616c
>
diff mbox

Patch

diff --git a/man2/open.2 b/man2/open.2
index 956531b24b26..be40dd7710df 100644
--- a/man2/open.2
+++ b/man2/open.2
@@ -716,6 +716,31 @@  XFS support was added
 .\" commit ab29743117f9f4c22ac44c13c1647fb24fb2bafe
 in Linux 3.15.
 .TP
+.B O_BENEATH " (since Linux 3.??)"
+Ensure that the
+.I pathname
+is beneath the current working directory (for
+.BR open (2))
+or the
+.I dirfd
+(for
+.BR openat (2)).
+If the
+.I pathname
+is absolute or contains a path component of "..", the
+.BR open ()
+fails with the error
+.BR EPERM.
+This occurs even if ".." path component would not actually
+escape the original directory; for example, a
+.I pathname
+of "subdir/../filename" would be rejected.
+Path components that are symbolic links to absolute paths, or that are
+relative paths containing a ".." component, will also cause the
+.BR open ()
+operation to fail with the error
+.BR EPERM.
+.TP
 .B O_TRUNC
 If the file already exists and is a regular file and the access mode allows
 writing (i.e., is
@@ -984,6 +1009,13 @@  did not match the owner of the file and the caller was not privileged
 The operation was prevented by a file seal; see
 .BR fcntl (2).
 .TP
+.B EPERM
+The
+.B O_BENEATH
+flag was specified and the
+.I pathname
+was not beneath the relevant directory.
+.TP
 .B EROFS
 .I pathname
 refers to a file on a read-only filesystem and write access was