Messages in this thread Patch in this message | | | From | Mark Brown <> | Subject | [PATCH 1/3] regmap: debugfs: Avoid overflows for very small reads | Date | Tue, 11 Dec 2012 01:25:30 +0900 |
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If count is less than the size of a register then we may hit integer wraparound when trying to move backwards to check if we're still in the buffer. Instead move the position forwards to check if it's still in the buffer, we are unlikely to be able to allocate a buffer sufficiently big to overflow here.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> --- drivers/base/regmap/regmap-debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 00fbd58..3df274e 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -93,7 +93,7 @@ static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from, /* If we're in the region the user is trying to read */ if (p >= *ppos) { /* ...but not beyond it */ - if (buf_pos >= count - 1 - map->debugfs_tot_len) + if (buf_pos + 1 + map->debugfs_tot_len >= count) break; /* Format the register */ -- 1.7.10.4
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