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| author | Jeff Mahoney <jeffm@suse.com> | 2009-05-11 14:25:34 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-11 12:18:06 -0700 |
| commit | 2b79bc4f7ebbd5af3c8b867968f9f15602d5f802 (patch) | |
| tree | 135f195357e108b1cc7b5ef0a09d1e32b79fcce0 | |
| parent | fd18de50b9e7965f93d231e7390436fb8900c0e6 (diff) | |
| download | lwn-2b79bc4f7ebbd5af3c8b867968f9f15602d5f802.tar.gz lwn-2b79bc4f7ebbd5af3c8b867968f9f15602d5f802.zip | |
dup2: Fix return value with oldfd == newfd and invalid fd
The return value of dup2 when oldfd == newfd and the fd isn't valid is
not getting properly sign extended. We end up with 4294967287 instead
of -EBADF.
I've reproduced this on SLE11 (2.6.27.21), openSUSE Factory
(2.6.29-rc5), and Ubuntu 9.04 (2.6.28).
This patch uses a signed int for the error value so it is properly
extended.
Commit 6c5d0512a091480c9f981162227fdb1c9d70e555 introduced this
regression.
Reported-by: Jiri Dluhos <jdluhos@novell.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/fcntl.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index cc8e4de2fee5..1ad703150dee 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -117,11 +117,13 @@ SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd) { if (unlikely(newfd == oldfd)) { /* corner case */ struct files_struct *files = current->files; + int retval = oldfd; + rcu_read_lock(); if (!fcheck_files(files, oldfd)) - oldfd = -EBADF; + retval = -EBADF; rcu_read_unlock(); - return oldfd; + return retval; } return sys_dup3(oldfd, newfd, 0); } |