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| author | Mike Frysinger <vapier@gentoo.org> | 2006-12-06 12:02:59 +1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-06 07:41:26 -0800 |
| commit | f81cff0d4067e41fd7383d9c013cc82da7c169d2 (patch) | |
| tree | 92c5c8a647e31be6b3e09dcce42ec261d43ad2f5 /mm/nommu.c | |
| parent | 3363c9b0ed8f6b5a241d63018cad242ae458cdf9 (diff) | |
| download | lwn-f81cff0d4067e41fd7383d9c013cc82da7c169d2.tar.gz lwn-f81cff0d4067e41fd7383d9c013cc82da7c169d2.zip | |
[PATCH] uclinux: fix mmap() of directory for nommu case
I was playing with blackfin when i hit a neat bug ... doing an open() on a
directory and then passing that fd to mmap() would cause the kernel to hang
after poking into the code a bit more, i found that
mm/nommu.c:validate_mmap_request() checks the length and if it is 0, just
returns the address ... this is in stark contrast to mmu's
mm/mmap.c:do_mmap_pgoff() where it returns -EINVAL for 0 length requests ...
i then noticed that some other parts of the logic is out of date between the
two funcs, so perhaps that's the easy fix ?
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/nommu.c')
| -rw-r--r-- | mm/nommu.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index 8bdde9508f3b..6a2a8aada401 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -497,15 +497,17 @@ static int validate_mmap_request(struct file *file, (flags & MAP_TYPE) != MAP_SHARED) return -EINVAL; - if (PAGE_ALIGN(len) == 0) - return addr; - - if (len > TASK_SIZE) + if (!len) return -EINVAL; + /* Careful about overflows.. */ + len = PAGE_ALIGN(len); + if (!len || len > TASK_SIZE) + return -ENOMEM; + /* offset overflow? */ if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) - return -EINVAL; + return -EOVERFLOW; if (file) { /* validate file mapping requests */ |