From: Mark Brown <[email protected]> 3.4.112-rc1 review patch. If anyone has any objections, please let me know.
------------------ commit b763ec17ac762470eec5be8ebcc43e4f8b2c2b82 upstream. If a read is attempted which is smaller than the line length then we may underflow the subtraction we're doing with the unsigned size_t type so move some of the calculation to be additions on the right hand side instead in order to avoid this. Reported-by: Rasmus Villemoes <[email protected]> Signed-off-by: Mark Brown <[email protected]> Signed-off-by: Zefan Li <[email protected]> --- 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 1db1289..d805eb5 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -205,7 +205,7 @@ static ssize_t regmap_access_read_file(struct file *file, /* 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 + tot_len + 1 >= count) break; /* Format the register */ -- 1.9.1
