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authorBadari Pulavarty <pbadari@us.ibm.com>2005-06-25 14:55:42 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-25 16:24:39 -0700
commitb0cfbd995d091b10841eeb948976f5d1fbf13cdd (patch)
treea693416656084c99581c8ef6d2ca830b0cfe13a9 /mm
parent8ae0b77811d97552b3b3c745e97de18849583bf7 (diff)
downloadlwn-b0cfbd995d091b10841eeb948976f5d1fbf13cdd.tar.gz
lwn-b0cfbd995d091b10841eeb948976f5d1fbf13cdd.zip
[PATCH] fix for generic_file_write iov problem
Here is the fix for the problem described in http://bugzilla.kernel.org/show_bug.cgi?id=4721 Basically, problem is generic_file_buffered_write() is accessing beyond end of the iov[] vector after handling the last vector. If we happen to cross page boundary, we get a fault. I think this simple patch is good enough. If we really don't want to depend on the "count", then we need pass nr_segs to filemap_set_next_iovec() and decrement it and check it. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index b573607b7112..c11418dd94e8 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1954,7 +1954,9 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
if (unlikely(nr_segs > 1)) {
filemap_set_next_iovec(&cur_iov,
&iov_base, status);
- buf = cur_iov->iov_base + iov_base;
+ if (count)
+ buf = cur_iov->iov_base +
+ iov_base;
} else {
iov_base += status;
}