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| author | Graff Yang <graff.yang@gmail.com> | 2009-08-19 01:11:17 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-08-19 03:31:13 +0400 |
| commit | 28d7a6ae92c099d81cbea08c20be0d2cf7ccd7ca (patch) | |
| tree | 7db56042d0c3e6749c749e1608b3e699485326cf /mm/nommu.c | |
| parent | 191529756633052680dd9d23ad63744ca5aa02a1 (diff) | |
| download | linux-28d7a6ae92c099d81cbea08c20be0d2cf7ccd7ca.tar.xz | |
nommu: check fd read permission in validate_mmap_request()
According to the POSIX (1003.1-2008), the file descriptor shall have been
opened with read permission, regardless of the protection options specified to
mmap(). The ltp test cases mmap06/07 need this.
Signed-off-by: Graff Yang <graff.yang@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/nommu.c')
| -rw-r--r-- | mm/nommu.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index 28754c40be98..4bde489ec431 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -919,6 +919,10 @@ 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) && |