Messages in this thread Patch in this message | | | Date | Thu, 14 May 2009 15:32:50 -0700 | From | Greg KH <> | Subject | [patch 15/51] dup2: Fix return value with oldfd == newfd and invalid fd |
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2.6.29-stable review patch. If anyone has any objections, please let us know.
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From: Jeff Mahoney <jeffm@suse.com>
commit 2b79bc4f7ebbd5af3c8b867968f9f15602d5f802 upstream.
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> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/fcntl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -117,11 +117,13 @@ SYSCALL_DEFINE2(dup2, unsigned int, oldf { 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); }
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