From e68726ff72cf7ba5e7d789857fcd9a75ca573f03 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 15 Aug 2012 13:01:24 +0200 Subject: [PATCH] vfs: canonicalize create mode in build_open_flags() Userspace can pass weird create mode in open(2) that we canonicalize to "(mode & S_IALLUGO) | S_IFREG" in vfs_create(). The problem is that we use the uncanonicalized mode before calling vfs_create() with unforseen consequences. So do the canonicalization early in build_open_flags(). Signed-off-by: Miklos Szeredi Tested-by: Richard W.M. Jones CC: stable@vger.kernel.org --- fs/open.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/open.c b/fs/open.c index bc132e167d2d..e1f2cdb91a4d 100644 --- a/fs/open.c +++ b/fs/open.c @@ -852,9 +852,10 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o int lookup_flags = 0; int acc_mode; - if (!(flags & O_CREAT)) - mode = 0; - op->mode = mode; + if (flags & O_CREAT) + op->mode = (mode & S_IALLUGO) | S_IFREG; + else + op->mode = 0; /* Must never be set by userspace */ flags &= ~FMODE_NONOTIFY;