As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kzalloc() function. This code was detected with the help of Coccinelle and audited and fixed manually. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Len Baker <len.baker@xxxxxxx> --- Changelog v1 -> v2 - Rebase against v5.15-rc2 - Remove the unnecessary "size" variable (Gustavo A. R. Silva). - Update the commit changelog to inform that this code was detected using a Coccinelle script (Gustavo A. R. Silva). drivers/scsi/advansys.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c index ffb391967573..e341b3372482 100644 --- a/drivers/scsi/advansys.c +++ b/drivers/scsi/advansys.c @@ -7477,8 +7477,8 @@ static int asc_build_req(struct asc_board *boardp, struct scsi_cmnd *scp, return ASC_ERROR; } - asc_sg_head = kzalloc(sizeof(asc_scsi_q->sg_head) + - use_sg * sizeof(struct asc_sg_list), GFP_ATOMIC); + asc_sg_head = kzalloc(struct_size(asc_sg_head, sg_list, use_sg), + GFP_ATOMIC); if (!asc_sg_head) { scsi_dma_unmap(scp); set_host_byte(scp, DID_SOFT_ERROR); -- 2.25.1
