diff mbox series

[bpf,1/2] libbpf: fix null dereference in xsk_socket__delete

Message ID 1604396490-12129-2-git-send-email-magnus.karlsson@gmail.com
State Not Applicable
Delegated to: BPF Maintainers
Headers show
Series libbpf: fix two bugs in xsk_socket__delete | expand

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Context Check Description
jkicinski/cover_letter success Link
jkicinski/fixes_present success Link
jkicinski/patch_count success Link
jkicinski/tree_selection success Clearly marked for bpf
jkicinski/subject_prefix success Link
jkicinski/source_inline success Was 0 now: 0
jkicinski/verify_signedoff success Link
jkicinski/module_param success Was 0 now: 0
jkicinski/build_32bit fail Errors and warnings before: 4 this patch: 4
jkicinski/kdoc success Errors and warnings before: 0 this patch: 0
jkicinski/verify_fixes success Link
jkicinski/checkpatch fail Link
jkicinski/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
jkicinski/header_inline success Link
jkicinski/stable success Stable not CCed

Commit Message

Magnus Karlsson Nov. 3, 2020, 9:41 a.m. UTC
From: Magnus Karlsson <magnus.karlsson@intel.com>

Fix a possible null pointer dereference in xsk_socket__delete that
will occur if a null pointer is fed into the function.

Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices")
Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
---
 tools/lib/bpf/xsk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Andrii Nakryiko Nov. 3, 2020, 7:02 p.m. UTC | #1
On Tue, Nov 3, 2020 at 1:41 AM Magnus Karlsson
<magnus.karlsson@gmail.com> wrote:
>
> From: Magnus Karlsson <magnus.karlsson@intel.com>
>
> Fix a possible null pointer dereference in xsk_socket__delete that
> will occur if a null pointer is fed into the function.
>
> Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices")
> Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
> ---

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  tools/lib/bpf/xsk.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
> index e3c98c0..504b7a8 100644
> --- a/tools/lib/bpf/xsk.c
> +++ b/tools/lib/bpf/xsk.c
> @@ -891,13 +891,14 @@ int xsk_umem__delete(struct xsk_umem *umem)
>  void xsk_socket__delete(struct xsk_socket *xsk)
>  {
>         size_t desc_sz = sizeof(struct xdp_desc);
> -       struct xsk_ctx *ctx = xsk->ctx;
>         struct xdp_mmap_offsets off;
> +       struct xsk_ctx *ctx;
>         int err;
>
>         if (!xsk)
>                 return;
>
> +       ctx = xsk->ctx;
>         if (ctx->prog_fd != -1) {
>                 xsk_delete_bpf_maps(xsk);
>                 close(ctx->prog_fd);
> --
> 2.7.4
>
diff mbox series

Patch

diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index e3c98c0..504b7a8 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -891,13 +891,14 @@  int xsk_umem__delete(struct xsk_umem *umem)
 void xsk_socket__delete(struct xsk_socket *xsk)
 {
 	size_t desc_sz = sizeof(struct xdp_desc);
-	struct xsk_ctx *ctx = xsk->ctx;
 	struct xdp_mmap_offsets off;
+	struct xsk_ctx *ctx;
 	int err;
 
 	if (!xsk)
 		return;
 
+	ctx = xsk->ctx;
 	if (ctx->prog_fd != -1) {
 		xsk_delete_bpf_maps(xsk);
 		close(ctx->prog_fd);