[PATCH 6.6 277/299] tools: ynl: make sure we always pass yarg to mnl_cb_run

Greg Kroah-Hartman
2024-02-27T14:00:54Z

From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit e4fe082c38cd74a8fa384bc7542cf3edf1cb7318 ]

There is one common error handler in ynl - ynl_cb_error().
It expects priv to be a pointer to struct ynl_parse_arg AKA yarg.
To avoid potential crashes if we encounter a stray NLMSG_ERROR
always pass yarg as priv (or a struct which has it as the first
member).

ynl_cb_null() has a similar problem directly - it expects yarg
but priv passed by the caller is ys.

Found by code inspection.

Fixes: 86878f14d71a ("tools: ynl: user space helpers")
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240220161112.2735195-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/net/ynl/lib/ynl.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/net/ynl/lib/ynl.c b/tools/net/ynl/lib/ynl.c
index 514e0d69e7310..0a7fe6a13f7b9 100644
--- a/tools/net/ynl/lib/ynl.c
+++ b/tools/net/ynl/lib/ynl.c
@@ -450,6 +450,8 @@ ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version)

int ynl_recv_ack(struct ynl_sock *ys, int ret)
{
+ struct ynl_parse_arg yarg = { .ys = ys, };
+
if (!ret) {
yerr(ys, YNL_ERROR_EXPECT_ACK,
"Expecting an ACK but nothing received");
@@ -462,7 +464,7 @@ int ynl_recv_ack(struct ynl_sock *ys, int ret)
return ret;
}
return mnl_cb_run(ys->rx_buf, ret, ys->seq, ys->portid,
- ynl_cb_null, ys);
+ ynl_cb_null, &yarg);
}

int ynl_cb_null(const struct nlmsghdr *nlh, void *data)
@@ -725,11 +727,14 @@ static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh)

static int ynl_ntf_trampoline(const struct nlmsghdr *nlh, void *data)
{
- return ynl_ntf_parse((struct ynl_sock *)data, nlh);
+ struct ynl_parse_arg *yarg = data;
+
+ return ynl_ntf_parse(yarg->ys, nlh);
}

int ynl_ntf_check(struct ynl_sock *ys)
{
+ struct ynl_parse_arg yarg = { .ys = ys, };
ssize_t len;
int err;

@@ -751,7 +756,7 @@ int ynl_ntf_check(struct ynl_sock *ys)
return len;

err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
- ynl_ntf_trampoline, ys,
+ ynl_ntf_trampoline, &yarg,
ynl_cb_array, NLMSG_MIN_TYPE);
if (err < 0)
return err;
--
2.43.0