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authorMike Frysinger <vapier@gentoo.org>2006-12-06 12:02:59 +1000
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-06 07:41:26 -0800
commitf81cff0d4067e41fd7383d9c013cc82da7c169d2 (patch)
tree92c5c8a647e31be6b3e09dcce42ec261d43ad2f5 /mm/nommu.c
parent3363c9b0ed8f6b5a241d63018cad242ae458cdf9 (diff)
downloadlinux-linaro-f81cff0d4067e41fd7383d9c013cc82da7c169d2.tar.gz
[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 i then noticed that some other parts of the logic is out of date between the two funcs, so perhaps that's the easy fix ?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.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 8bdde9508f3..6a2a8aada40 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 */