[PATCH v3 2/4] lib/string_helpers.c: protect string_get_size() against blk_size=0

From: Vitaly Kuznetsov
Date: Thu Oct 29 2015 - 12:31:04 EST


Division by zero happens if blk_size=0 is supplied to string_get_size().
Add WARN_ON() and set size to 0 to report '0 B'.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
lib/string_helpers.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index f6c27dc..ff3575b 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -50,6 +50,11 @@ void string_get_size(u64 size, u32 blk_size, const enum string_size_units units,

tmp[0] = '\0';
i = 0;
+
+ /* Calling string_get_size() with blk_size=0 is wrong! */
+ if (WARN_ON(!blk_size))
+ size = 0;
+
if (!size)
goto out;

--
2.4.3

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