mtd: correct upper bounds check for mtd_*() APIs

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=0c2b4e21444d0e274e91fc7db85caddb30988853
Commit:     0c2b4e21444d0e274e91fc7db85caddb30988853
Parent:     36c6a7ac74044b8025488c018279115bb3c32eb0
Author:     Brian Norris <computersforpeace at gmail.com>
AuthorDate: Mon Jul 21 19:06:27 2014 -0700
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Tue Aug 19 11:53:07 2014 -0700

    mtd: correct upper bounds check for mtd_*() APIs
    
    When checking the upper boundary (i.e., whether an address is higher
    than the maximum size of the MTD), we should be doing an inclusive check
    (greater or equal). For instance, an address of 16MB (0x1000000) on a
    16MB device is invalid.
    
    The strengthening of this bounds check is redundant for those which
    already have a address+length check and ensure that the length is
    non-zero, but let's just fix them all, for completeness.
    
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/mtdcore.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index e4831b4..c101517 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -778,7 +778,7 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
  */
 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
-	if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
+	if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
 		return -EINVAL;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
@@ -804,7 +804,7 @@ int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 		*phys = 0;
 	if (!mtd->_point)
 		return -EOPNOTSUPP;
-	if (from < 0 || from > mtd->size || len > mtd->size - from)
+	if (from < 0 || from >= mtd->size || len > mtd->size - from)
 		return -EINVAL;
 	if (!len)
 		return 0;
@@ -817,7 +817,7 @@ int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 {
 	if (!mtd->_point)
 		return -EOPNOTSUPP;
-	if (from < 0 || from > mtd->size || len > mtd->size - from)
+	if (from < 0 || from >= mtd->size || len > mtd->size - from)
 		return -EINVAL;
 	if (!len)
 		return 0;
@@ -835,7 +835,7 @@ unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
 {
 	if (!mtd->_get_unmapped_area)
 		return -EOPNOTSUPP;
-	if (offset > mtd->size || len > mtd->size - offset)
+	if (offset >= mtd->size || len > mtd->size - offset)
 		return -EINVAL;
 	return mtd->_get_unmapped_area(mtd, len, offset, flags);
 }
@@ -846,7 +846,7 @@ int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 {
 	int ret_code;
 	*retlen = 0;
-	if (from < 0 || from > mtd->size || len > mtd->size - from)
+	if (from < 0 || from >= mtd->size || len > mtd->size - from)
 		return -EINVAL;
 	if (!len)
 		return 0;
@@ -869,7 +869,7 @@ int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
 	      const u_char *buf)
 {
 	*retlen = 0;
-	if (to < 0 || to > mtd->size || len > mtd->size - to)
+	if (to < 0 || to >= mtd->size || len > mtd->size - to)
 		return -EINVAL;
 	if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
@@ -892,7 +892,7 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
 	*retlen = 0;
 	if (!mtd->_panic_write)
 		return -EOPNOTSUPP;
-	if (to < 0 || to > mtd->size || len > mtd->size - to)
+	if (to < 0 || to >= mtd->size || len > mtd->size - to)
 		return -EINVAL;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
@@ -1011,7 +1011,7 @@ int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	if (!mtd->_lock)
 		return -EOPNOTSUPP;
-	if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
+	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
 		return -EINVAL;
 	if (!len)
 		return 0;
@@ -1023,7 +1023,7 @@ int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	if (!mtd->_unlock)
 		return -EOPNOTSUPP;
-	if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
+	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
 		return -EINVAL;
 	if (!len)
 		return 0;
@@ -1035,7 +1035,7 @@ int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	if (!mtd->_is_locked)
 		return -EOPNOTSUPP;
-	if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
+	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
 		return -EINVAL;
 	if (!len)
 		return 0;
@@ -1045,7 +1045,7 @@ EXPORT_SYMBOL_GPL(mtd_is_locked);
 
 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 {
-	if (ofs < 0 || ofs > mtd->size)
+	if (ofs < 0 || ofs >= mtd->size)
 		return -EINVAL;
 	if (!mtd->_block_isreserved)
 		return 0;
@@ -1055,7 +1055,7 @@ EXPORT_SYMBOL_GPL(mtd_block_isreserved);
 
 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
-	if (ofs < 0 || ofs > mtd->size)
+	if (ofs < 0 || ofs >= mtd->size)
 		return -EINVAL;
 	if (!mtd->_block_isbad)
 		return 0;
@@ -1067,7 +1067,7 @@ int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
 {
 	if (!mtd->_block_markbad)
 		return -EOPNOTSUPP;
-	if (ofs < 0 || ofs > mtd->size)
+	if (ofs < 0 || ofs >= mtd->size)
 		return -EINVAL;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;