| Message ID | 20230819083941.164365-1-wangzhu9@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [-next] scsi: snic: fix double free in snic_tgt_create() | expand |
Zhu, > The commit 41320b18a0e0 ("scsi: snic: Fix possible memory leak if > device_add() fails") fix the memory leak caused by dev_set_name() when > device_add() failed. While it did not consider that 'tgt' has already > been released when put_device(&tgt->dev) is called. We removed > kfree(tgt) in the error path to avoid double free 'tgt'. Where is tgt freed prior to the kfree() call?
> put_device(&tgt->dev) will call snic_tgt_dev_release() in which > kfree(tgt) is called, so tgt is freed twice OK, I get it. Thanks!
On Sat, 19 Aug 2023 08:39:41 +0000, Zhu Wang wrote: > The commit 41320b18a0e0 ("scsi: snic: Fix possible memory leak if > device_add() fails") fix the memory leak caused by dev_set_name() when > device_add() failed. While it did not consider that 'tgt' has already been > released when put_device(&tgt->dev) is called. We removed kfree(tgt) in > the error path to avoid double free 'tgt'. And we moved > put_device(&tgt->dev) after the removed kfree(tgt) to avoid UAF > (Use-After-Free). > > [...] Applied to 6.5/scsi-fixes, thanks! [1/1] scsi: snic: fix double free in snic_tgt_create() https://git.kernel.org/mkp/scsi/c/1bd3a76880b2
diff --git a/drivers/scsi/snic/snic_disc.c b/drivers/scsi/snic/snic_disc.c index e429ad23c396..4db3ba62fcd3 100644 --- a/drivers/scsi/snic/snic_disc.c +++ b/drivers/scsi/snic/snic_disc.c @@ -303,12 +303,11 @@ snic_tgt_create(struct snic *snic, struct snic_tgt_id *tgtid) "Snic Tgt: device_add, with err = %d\n", ret); - put_device(&tgt->dev); put_device(&snic->shost->shost_gendev); spin_lock_irqsave(snic->shost->host_lock, flags); list_del(&tgt->list); spin_unlock_irqrestore(snic->shost->host_lock, flags); - kfree(tgt); + put_device(&tgt->dev); tgt = NULL; return tgt;
The commit 41320b18a0e0 ("scsi: snic: Fix possible memory leak if device_add() fails") fix the memory leak caused by dev_set_name() when device_add() failed. While it did not consider that 'tgt' has already been released when put_device(&tgt->dev) is called. We removed kfree(tgt) in the error path to avoid double free 'tgt'. And we moved put_device(&tgt->dev) after the removed kfree(tgt) to avoid UAF (Use-After-Free). Fixes: 41320b18a0e0 ("scsi: snic: Fix possible memory leak if device_add() fails") Signed-off-by: Zhu Wang <wangzhu9@huawei.com> --- drivers/scsi/snic/snic_disc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)