On 08/16/2012 02:20 PM, Kasatkin, Dmitry wrote:Hello,
Some places in the code uses variable-size allocation on stack..
For example from hmac_setkey():
struct {
struct shash_desc shash;
char ctx[crypto_shash_descsize(hash)];
} desc;
sparse complains
CHECK crypto/hmac.c
crypto/hmac.c:57:47: error: bad constant expression
I like it instead of kmalloc..
But what is position of kernel community about it?
If you know that the range of crypto_shash_descsize(hash) is bounded, just use the upper bound.
If the range of crypto_shash_descsize(hash) is unbounded, then the stack will overflow and ... BOOM!