4.19-stable review patch. If anyone has any objections, please let me know.
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From: Sergey Shtylyov s.shtylyov@omp.ru
[ Upstream commit 86222a8fc16ec517de8da2604d904c9df3a08e5d ]
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 *size_t* 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 s.shtylyov@omp.ru Link: https://lore.kernel.org/r/20231105202936.25694-1-s.shtylyov@omp.ru Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 efb765b8466f..a6e5022469ab 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -189,7 +189,7 @@ static int persistent_ram_init_ecc(struct persistent_ram_zone *prz, { int numerr; struct persistent_ram_buffer *buffer = prz->buffer; - int ecc_blocks; + size_t ecc_blocks; size_t ecc_total;
if (!ecc_info || !ecc_info->ecc_size)