diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-12-11 01:14:11 +0900 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-01-03 03:33:32 +0000 |
| commit | 71f1e737a5ab8cc3c1384117222ef82c99bc056d (patch) | |
| tree | 0869ca036b3e01d7efc00318a8a29d5c58775f8c /drivers/base | |
| parent | 19afa7002ed6c2cf51c85ce5e2c2eaaf55e771c3 (diff) | |
regmap: debugfs: Avoid overflows for very small reads
commit db04328c167ff8e7c57f4a3532214aeada3a82fd upstream.
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>
[bwh: Backported to 3.2: formatted length is tot_len]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/regmap/regmap-debugfs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 6f397476e27..cd252e0f747 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -67,7 +67,7 @@ static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf, /* If we're in the region the user is trying to read */ if (p >= *ppos) { /* ...but not beyond it */ - if (buf_pos >= count - 1 - tot_len) + if (buf_pos + 1 + tot_len >= count) break; /* Format the register */ |