Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH 1/2] block: drbd: Fix a possible null-pointer dereference in receive_protocol() | Date | Wed, 24 Jul 2019 11:49:16 +0800 |
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In receive_protocol(), when crypto_alloc_shash() on line 3754 fails, peer_integrity_tfm is NULL, and error handling code is executed. In this code, crypto_free_shash() is called with NULL, which can cause a null-pointer dereference, because: crypto_free_shash(NULL) crypto_ahash_tfm(NULL) "return &NULL->base"
To fix this bug, peer_integrity_tfm is checked before calling crypto_free_shash().
This bug is found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/block/drbd/drbd_receiver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 90ebfcae0ce6..a4df2b8291f6 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -3807,7 +3807,8 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in disconnect_rcu_unlock: rcu_read_unlock(); disconnect: - crypto_free_shash(peer_integrity_tfm); + if (peer_integrity_tfm) + crypto_free_shash(peer_integrity_tfm); kfree(int_dig_in); kfree(int_dig_vv); conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); -- 2.17.0
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