In persistent_ram_init_ecc(), on 64-bit arches DIV_ROUND_UP() will return
64-bit value since persistent_ram_zone::buffer_size has type size_t which
is derived from the 64-bit *unsigned long*, while the ecc_blocks variable
this value gets assigned to has (always 32-bit) *int* type. Even if that
value fits into *int* type, an overflow is still possible when calculating
the size_t typed ecc_total variable further below since there's no cast to
any 64-bit type before multiplication. Declaring the ecc_blocks variable
as *unsigned long* should fix this mess...
Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.
Fixes: 9cc05ad97c57 ("staging: android: persistent_ram: refactor ecc support")
Signed-off-by: Sergey Shtylyov <[email protected]>
---
The patch is against the 'master' branch of Linus Torvalds' repo.
fs/pstore/ram_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 650e437b55e6..131c1923b8c0 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -190,7 +190,7 @@ static int persistent_ram_init_ecc(struct
persistent_ram_zone *prz,
{
int numerr;
struct persistent_ram_buffer *buffer = prz->buffer;
- int ecc_blocks;
+ unsigned long ecc_blocks;
size_t ecc_total;
if (!ecc_info || !ecc_info->ecc_size)
--
2.26.3
