From: Mark Brown Date: Mon, 10 Dec 2012 16:14:11 +0000 (+0900) Subject: regmap: debugfs: Avoid overflows for very small reads X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=db04328c167ff8e7c57f4a3532214aeada3a82fd;p=linux.git 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 --- diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 00fbd58706b22..3df274e060624 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 */