The patch titled
dup2: fix return value with oldfd == newfd and invalid fd
has been added to the -mm tree. Its filename is
dup2-fix-return-value-with-oldfd-==-newfd-and-invalid-fd.patch
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------------------------------------------------------
Subject: dup2: fix return value with oldfd == newfd and invalid fd
From: Jeff Mahoney <jeffm@xxxxxxxx>
Fix a regression introduced with 6c5d0512a091480c9f981162227fdb1c9d70e555
("get rid of corner case in dup3() entirely").
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.
Reported-by: Jiri Dluhos <jdluhos@xxxxxxxxxx>
Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/fcntl.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff -puN fs/fcntl.c~dup2-fix-return-value-with-oldfd-==-newfd-and-invalid-fd fs/fcntl.c
--- a/fs/fcntl.c~dup2-fix-return-value-with-oldfd-==-newfd-and-invalid-fd
+++ a/fs/fcntl.c
@@ -115,13 +115,14 @@ out_unlock:
SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd)
{
+ int ret = oldfd;
if (unlikely(newfd == oldfd)) { /* corner case */
struct files_struct *files = current->files;
rcu_read_lock();
if (!fcheck_files(files, oldfd))
- oldfd = -EBADF;
+ ret = -EBADF;
rcu_read_unlock();
- return oldfd;
+ return ret;
}
return sys_dup3(oldfd, newfd, 0);
}
_
Patches currently in -mm which might be from jeffm@xxxxxxxx are
origin.patch
dup2-fix-return-value-with-oldfd-==-newfd-and-invalid-fd.patch
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