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authorMark Brown <broonie@opensource.wolfsonmicro.com>2012-12-11 01:14:11 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-17 08:50:54 -0800
commitba1de754297ed6756f0a6281f3e41a0ef9ff0d77 (patch)
tree3524c7b437617fef4226e74bf219e7d916163bd4 /drivers/base
parentdc4a02c677c9667dcd7d118cee09a99ede9c64f4 (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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/regmap/regmap-debugfs.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index 251eb70f83e..8ab1eab90be 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -90,7 +90,7 @@ 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 */