On 01/26/2017 10:05 AM, Dan Carpenter wrote:
> Say we got really unlucky and these failed on the last iteration, then
> it could lead to a use after free bug.
thanks for reporting this! I had already a similar patch prepared, but not
yet submitted. It contains all your added lines plus these additional
pre-initializations at definition time:
@@ -509,7 +509,7 @@ int smc_sndbuf_create(struct smc_sock *smc)
struct smc_connection *conn = &smc->conn;
struct smc_link_group *lgr = conn->lgr;
int tmp_bufsize, tmp_bufsize_short;
- struct smc_buf_desc *sndbuf_desc;
+ struct smc_buf_desc *sndbuf_desc = NULL;
int rc;
/* use socket send buffer size (w/o overhead) as start value */
@@ -573,7 +575,7 @@ int smc_rmb_create(struct smc_sock *smc)
struct smc_connection *conn = &smc->conn;
struct smc_link_group *lgr = conn->lgr;
int tmp_bufsize, tmp_bufsize_short;
- struct smc_buf_desc *rmb_desc;
+ struct smc_buf_desc *rmb_desc = NULL;
int rc;
/* use socket recv buffer size (w/o overhead) as start value */
If you do not contradict, I will post my enhanced patch version.
>
> Fixes: cd6851f30386 ("smc: remote memory buffers (RMBs)")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
> index 8b1d34378829..941279e1504e 100644
> --- a/net/smc/smc_core.c
> +++ b/net/smc/smc_core.c
> @@ -535,6 +535,7 @@ int smc_sndbuf_create(struct smc_sock *smc)
> /* if send buffer allocation has failed,
> * try a smaller one
> */
> + sndbuf_desc = NULL;
> continue;
> }
> rc = smc_ib_buf_map(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
> @@ -543,6 +544,7 @@ int smc_sndbuf_create(struct smc_sock *smc)
> if (rc) {
> kfree(sndbuf_desc->cpu_addr);
> kfree(sndbuf_desc);
> + sndbuf_desc = NULL;
> continue; /* if mapping failed, try smaller one */
> }
> sndbuf_desc->used = 1;
> @@ -599,6 +601,7 @@ int smc_rmb_create(struct smc_sock *smc)
> /* if RMB allocation has failed,
> * try a smaller one
> */
> + rmb_desc = NULL;
> continue;
> }
> rc = smc_ib_buf_map(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
> @@ -607,6 +610,7 @@ int smc_rmb_create(struct smc_sock *smc)
> if (rc) {
> kfree(rmb_desc->cpu_addr);
> kfree(rmb_desc);
> + rmb_desc = NULL;
> continue; /* if mapping failed, try smaller one */
> }
> rc = smc_ib_get_memory_region(lgr->lnk[SMC_SINGLE_LINK].roce_pd,
> @@ -619,6 +623,7 @@ int smc_rmb_create(struct smc_sock *smc)
> DMA_FROM_DEVICE);
> kfree(rmb_desc->cpu_addr);
> kfree(rmb_desc);
> + rmb_desc = NULL;
> continue;
> }
> rmb_desc->used = 1;
>
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