From db04328c167ff8e7c57f4a3532214aeada3a82fd Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 11 Dec 2012 01:14:11 +0900 Subject: [PATCH] regmap: debugfs: Avoid overflows for very small reads 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 Cc: stable@vger.kernel.org --- 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 00fbd58706b2..3df274e06062 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 */ -- GitLab