At Thu, 14 Mar 2013 17:11:21 +1030, Rusty Russell wrote: > > Satoru Takeuchi <[email protected]> writes: > > Hi Rusty, > > > > At Tue, 12 Mar 2013 15:43:33 -0700, > > Greg Kroah-Hartman wrote: > >> @@ -307,6 +312,14 @@ int hwrng_register(struct hwrng *rng) > >> > >> mutex_lock(&rng_mutex); > >> > >> + /* kmalloc makes this safe for virt_to_page() in virtio_rng.c */ > >> + err = -ENOMEM; > >> + if (!rng_buffer) { > >> + rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL); > > > > rng_buffer is now kmalloc-ed, but not kfree-ed. Shoudn't it be kfree-ed > > at hwrng_unregister()? If my suspect is correct, the same problem is > > in 3.8.3-rc1 and 3.0.69-rc1. I'm OK to make a patch, but it'll be after > > some hours. > > > > Corecct me if I'm wrong. > > Yes, it would be nice to free it, but it really makes sense to free it > in module_cleanup() (which would have to be written, as the module > currently doesn't have one). > > Cheers, > Rusty.
From: Satoru Takeuchi <[email protected]> rng-core module allocates rng_buffer by kmalloc() since commit f7f154f1246ccc5a0a7e9ce50932627d60a0c878. But this buffer won't be freed and there is a memory leak possibility at module exit. Signed-off-by: Satoru Takeuchi <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Matt Mackall <[email protected]> Cc: Herbert Xu <[email protected]> Cc: Aurelien Jarno <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: [email protected] --- drivers/char/hw_random/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 69ae597..a0f7724 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -380,6 +380,15 @@ void hwrng_unregister(struct hwrng *rng) } EXPORT_SYMBOL_GPL(hwrng_unregister); +static void __exit hwrng_exit(void) +{ + mutex_lock(&rng_mutex); + BUG_ON(current_rng); + kfree(rng_buffer); + mutex_unlock(&rng_mutex); +} + +module_exit(hwrng_exit); MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver"); MODULE_LICENSE("GPL"); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
