[ 21/54] md: Avoid write invalid address if read_seqretry returned true.
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2012-11-30 19:02:11
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3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: majianpeng <redacted> commit 35f9ac2dcec8f79d7059ce174fd7b7ee3290d620 upstream. If read_seqretry returned true and bbp was changed, it will write invalid address which can cause some serious problem. This bug was introduced by commit v3.0-rc7-130-g2699b67. So fix is suitable for 3.0.y thru 3.6.y. Reported-by: zhuwenfeng@kedacom.com Tested-by: zhuwenfeng@kedacom.com Signed-off-by: Jianpeng Ma <redacted> Signed-off-by: NeilBrown <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/md/md.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c@@ -1832,10 +1832,10 @@ retry: memset(bbp, 0xff, PAGE_SIZE); for (i = 0 ; i < bb->count ; i++) { - u64 internal_bb = *p++; + u64 internal_bb = p[i]; u64 store_bb = ((BB_OFFSET(internal_bb) << 10) | BB_LEN(internal_bb)); - *bbp++ = cpu_to_le64(store_bb); + bbp[i] = cpu_to_le64(store_bb); } bb->changed = 0; if (read_seqretry(&bb->lock, seq))