[PATCH] mtd-utils: Check mtdoffset is not larger than mtd.size in case of a bad block.

* [PATCH] mtd-utils: Check mtdoffset is not larger than mtd.size in case of a bad block.
@ 2012-06-26 21:46 Tomer Barletz
  2012-06-29  8:32 ` Artem Bityutskiy
  0 siblings, 1 reply; 2+ messages in thread
From: Tomer Barletz @ 2012-06-26 21:46 UTC (permalink / raw)
  To: linux-mtd

mtdoffset is being tested against mtd.size in the outer two loops, but 
the third nested one does not test against it.
In case of a bad block we'll try to access an out of bounds offset in 
the next MEMGETBADBLOCK ioctl, which will fail with EINVAL.
In case mtdoffset is indeed larger than the partition size, we need to 
bail, since there are not enough "good" blocks to complete the write.

Signed-off-by: Tomer Barletz <barletz@gmail.com>
---
  nandwrite.c |    5 +++++
  1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/nandwrite.c b/nandwrite.c
index a42f7c9..8bd00c1 100644
--- a/nandwrite.c
+++ b/nandwrite.c
@@ -399,6 +399,11 @@ int main(int argc, char * const argv[])

  				if (baderaseblock) {
  					mtdoffset = blockstart + ebsize_aligned;
+
+					if (mtdoffset > mtd.size) {
+						perror("Too many bad blocks - cannot complete request.");
+						goto closeall;
+					}
  				}
  				offs +=  ebsize_aligned / blockalign;
  			} while (offs < blockstart + ebsize_aligned);
-- 
1.7.1


--Tomer

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