diff mbox series

[bpf] libbpf: fix potential NULL pointer dereference

Message ID 20210408052009.7844-1-ciara.loftus@intel.com
State New
Headers show
Series [bpf] libbpf: fix potential NULL pointer dereference | expand

Commit Message

Loftus, Ciara April 8, 2021, 5:20 a.m. UTC 
Wait until after the UMEM is checked for null to dereference it.

Fixes: 43f1bc1efff1 ("libbpf: Restore umem state after socket create failure")

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
 tools/lib/bpf/xsk.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Daniel Borkmann April 8, 2021, 9:38 p.m. UTC | #1 
On 4/8/21 7:20 AM, Ciara Loftus wrote:
> Wait until after the UMEM is checked for null to dereference it.
> 
> Fixes: 43f1bc1efff1 ("libbpf: Restore umem state after socket create failure")
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>

Applied, thanks!
diff mbox series

Patch

diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index d24b5cc720ec..770040d1f893 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -858,12 +858,14 @@  int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
 	struct xsk_socket *xsk;
 	struct xsk_ctx *ctx;
 	int err, ifindex;
-	bool unmap = umem->fill_save != fill;
+	bool unmap;
 	bool rx_setup_done = false, tx_setup_done = false;
 
 	if (!umem || !xsk_ptr || !(rx || tx))
 		return -EFAULT;
 
+	unmap = umem->fill_save != fill;
+
 	xsk = calloc(1, sizeof(*xsk));
 	if (!xsk)
 		return -ENOMEM;