Messages in this thread Patch in this message | | | From | <> | Subject | [PATCH] mm/nommu.c: check read permission in validate_mmap_request() | Date | Fri, 14 Aug 2009 11:19:21 +0800 |
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From: Graff Yang <graff.yang@gmail.com>
According to the POSIX (1003.1-2008), the file shall have been opened with read permission, regardless of the protection options specified. The ltp test cases mmap06/07 need this.
Signed-off-by: Graff Yang <graff.yang@gmail.com> --- mm/nommu.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/mm/nommu.c b/mm/nommu.c index 53cab10..ac13b23 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -922,6 +922,10 @@ static int validate_mmap_request(struct file *file, if (!file->f_op->read) capabilities &= ~BDI_CAP_MAP_COPY; + /* The file shall have been opened with read permission. */ + if (!(file->f_mode & FMODE_READ)) + return -EACCES; + if (flags & MAP_SHARED) { /* do checks for writing, appending and locking */ if ((prot & PROT_WRITE) && -- 1.6.1
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