[PATCH v2] hwrng: Clean up RNG list when last hwrng is unregistered
Commit 142a27f0a731 added support for a "best" RNG, and in doing so
introduced a hang from rmmod/modprobe -r when the last RNG on the list
was unloaded.
When the hwrng list is depleted, return the global variables to their
original state and decrement all references to the object.
Fixes: 142a27f0a731 ("hwrng: core - Reset user selected rng by writing "" to
rng_current")
Signed-off-by: Gary R Hook
---
Changes since v1: fix misspelled word in subject
drivers/char/hw_random/core.c |4
1 file changed, 4 insertions(+)
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 657b8770b6b9..91bb98c42a1c 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -306,6 +306,10 @@ static int enable_best_rng(void)
ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng));
if (!ret)
cur_rng_set_by_user = 0;
+ } else {
+ drop_current_rng();
+ cur_rng_set_by_user = 0;
+ ret = 0;
}
return ret;
Re: general protection fault in ___cache_free
On Fri, Dec 15, 2017 at 12:02:01AM -0800, syzbot wrote: > Call Trace: > __cache_free mm/slab.c:3494 [inline] > kfree+0x1a3/0x250 mm/slab.c:3806 > blkcipher_walk_done+0x72b/0xde0 crypto/blkcipher.c:139 > encrypt+0x20e/0x540 arch/x86/crypto/salsa20_glue.c:79 > skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline] > skcipher_decrypt_blkcipher+0x213/0x310 crypto/skcipher.c:640 > crypto_skcipher_decrypt include/crypto/skcipher.h:463 [inline] > _skcipher_recvmsg crypto/algif_skcipher.c:144 [inline] > skcipher_recvmsg+0xa54/0xf20 crypto/algif_skcipher.c:165 > sock_recvmsg_nosec net/socket.c:809 [inline] > sock_recvmsg+0xc9/0x110 net/socket.c:816 > ___sys_recvmsg+0x29b/0x630 net/socket.c:2185 > __sys_recvmsg+0xe2/0x210 net/socket.c:2230 > SYSC_recvmsg net/socket.c:2242 [inline] > SyS_recvmsg+0x2d/0x50 net/socket.c:2237 > entry_SYSCALL_64_fastpath+0x1f/0x96 Already fixed: #syz fix: crypto: salsa20 - fix blkcipher_walk API usage
