[PATCH v3] nbd: Fix memory leak in nbd_add_socket
STALE2295d
From: Zheng Bin <hidden>
Date: 2020-06-22 11:13:09
Also in:
lkml
Subsystem:
block layer, network block device (nbd), the rest · Maintainers:
Jens Axboe, Josef Bacik, Linus Torvalds
When adding first socket to nbd, if nsock's allocation failed, the data
structure member "config->socks" was reallocated, but the data structure
member "config->num_connections" was not updated. A memory leak will occur
then because the function "nbd_config_put" will free "config->socks" only
when "config->num_connections" is not zero.
Fixes: 03bf73c315ed ("nbd: prevent memory leak")
Signed-off-by: Zheng Bin <redacted>
---
v1->v2: improve change description
v2->v3: fix some code style issues, improve change description, thanks to
Markus for the review.
drivers/block/nbd.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 43cff01a5a67..ce7e9f223b20 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c@@ -1033,25 +1033,26 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, test_bit(NBD_RT_BOUND, &config->runtime_flags))) { dev_err(disk_to_dev(nbd->disk), "Device being setup by another task"); - sockfd_put(sock); - return -EBUSY; + err = -EBUSY; + goto put_socket; + } + + nsock = kzalloc(sizeof(*nsock), GFP_KERNEL); + if (!nsock) { + err = -ENOMEM; + goto put_socket; } socks = krealloc(config->socks, (config->num_connections + 1) * sizeof(struct nbd_sock *), GFP_KERNEL); if (!socks) { - sockfd_put(sock); - return -ENOMEM; + kfree(nsock); + err = -ENOMEM; + goto put_socket; } config->socks = socks; - nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL); - if (!nsock) { - sockfd_put(sock); - return -ENOMEM; - } - nsock->fallback_index = -1; nsock->dead = false; mutex_init(&nsock->tx_lock);
@@ -1063,6 +1064,10 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, atomic_inc(&config->live_connections); return 0; + +put_socket: + sockfd_put(sock); + return err; } static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg) --
2.26.0.106.g9fadedd