The issue happens on some error handling paths. When the function
fails to grab the object `xprt`, it simply returns 0, forgetting to
decrease the reference count of another object `xps`, which is
increased by rpc_sysfs_xprt_kobj_get_xprt_switch(), causing refcount
leaks. Also, the function forgets to check whether `xps` is valid
before using it, which may result in NULL-dereferencing issues.
Fix it by adding proper error handling code when either `xprt` or
`xps` is NULL.
Fixes: 5b7eb78486cd ("SUNRPC: take a xprt offline using sysfs")
Signed-off-by: Xin Xiong <[email protected]>
Signed-off-by: Xin Tan <[email protected]>
---
net/sunrpc/sysfs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index a3a2f8aeb80e..d1a15c6d3fd9 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -291,8 +291,10 @@ static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,
int offline = 0, online = 0, remove = 0;
struct rpc_xprt_switch *xps = rpc_sysfs_xprt_kobj_get_xprt_switch(kobj);
- if (!xprt)
- return 0;
+ if (!xprt || !xps) {
+ count = 0;
+ goto out_put;
+ }
if (!strncmp(buf, "offline", 7))
offline = 1;
--
2.25.1
Hello:
This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:
On Wed, 10 Aug 2022 23:29:13 +0800 you wrote:
> The issue happens on some error handling paths. When the function
> fails to grab the object `xprt`, it simply returns 0, forgetting to
> decrease the reference count of another object `xps`, which is
> increased by rpc_sysfs_xprt_kobj_get_xprt_switch(), causing refcount
> leaks. Also, the function forgets to check whether `xps` is valid
> before using it, which may result in NULL-dereferencing issues.
>
> [...]
Here is the summary with links:
- net/sunrpc: fix potential memory leaks in rpc_sysfs_xprt_state_change()
https://git.kernel.org/netdev/net/c/bfc48f1b0505
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html