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| author | Richard W.M. Jones <rjones@redhat.com> | 2012-10-09 15:27:43 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-09 23:33:38 -0400 |
| commit | aed976475bff939672b0e21595839c445dcec0fa (patch) | |
| tree | a260411639546dad441bf6060be123ca0842a31c /fs/file.c | |
| parent | d1c7d97ad58836affde6e39980b96527510b572e (diff) | |
| download | lwn-aed976475bff939672b0e21595839c445dcec0fa.tar.gz lwn-aed976475bff939672b0e21595839c445dcec0fa.zip | |
dup3: Return an error when oldfd == newfd.
I have tested the attached patch to fix the dup3 regression.
Rich.
From 0944e30e12dec6544b3602626b60ff412375c78f Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Tue, 9 Oct 2012 14:42:45 +0100
Subject: [PATCH] dup3: Return an error when oldfd == newfd.
The following commit:
commit fe17f22d7fd0e344ef6447238f799bb49f670c6f
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Tue Aug 21 11:48:11 2012 -0400
take purely descriptor-related stuff from fcntl.c to file.c
was supposed to be just code motion, but it dropped the following two
lines:
if (unlikely(oldfd == newfd))
return -EINVAL;
from the dup3 system call. dup3 is not specified by POSIX, so Linux
can do what it likes. However the POSIX proposal for dup3 [1] states
that it should return an error if oldfd == newfd.
[1] http://austingroupbugs.net/view.php?id=411
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/file.c')
| -rw-r--r-- | fs/file.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/file.c b/fs/file.c index 0f1bda4bebfa..d3b5fa80b71b 100644 --- a/fs/file.c +++ b/fs/file.c @@ -922,6 +922,9 @@ SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags) if ((flags & ~O_CLOEXEC) != 0) return -EINVAL; + if (unlikely(oldfd == newfd)) + return -EINVAL; + if (newfd >= rlimit(RLIMIT_NOFILE)) return -EMFILE; |