diff mbox series

[v4] net: mdiobus: fix an OF node reference leak

Message ID 20241218035106.1436405-1-joe@pf.is.s.u-tokyo.ac.jp (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [v4] net: mdiobus: fix an OF node reference leak | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: ioana.ciornei@nxp.com; 1 maintainers not CCed: ioana.ciornei@nxp.com
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 26 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2024-12-18--06-00 (tests: 868)

Commit Message

Joe Hattori Dec. 18, 2024, 3:51 a.m. UTC 
fwnode_find_mii_timestamper() calls of_parse_phandle_with_fixed_args()
but does not decrement the refcount of the obtained OF node. Add an
of_node_put() call before returning from the function.

This bug was detected by an experimental static analysis tool that I am
developing.

Fixes: bc1bee3b87ee ("net: mdiobus: Introduce fwnode_mdiobus_register_phy()")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
---
Changes in v4:
- Reorder the variables.
- Add and use put_node label for cleanup.

Changes in v3:
- Call of_node_put() when arg.args_count != 1 holds.

Changes in v2:
- Call of_node_put() after calling register_mii_timestamper() to avoid
  UAF.
---
 drivers/net/mdio/fwnode_mdio.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c
index b156493d7084..aea0f0357568 100644
--- a/drivers/net/mdio/fwnode_mdio.c
+++ b/drivers/net/mdio/fwnode_mdio.c
@@ -40,6 +40,7 @@  fwnode_find_pse_control(struct fwnode_handle *fwnode)
 static struct mii_timestamper *
 fwnode_find_mii_timestamper(struct fwnode_handle *fwnode)
 {
+	struct mii_timestamper *mii_ts;
 	struct of_phandle_args arg;
 	int err;
 
@@ -53,10 +54,16 @@  fwnode_find_mii_timestamper(struct fwnode_handle *fwnode)
 	else if (err)
 		return ERR_PTR(err);
 
-	if (arg.args_count != 1)
-		return ERR_PTR(-EINVAL);
+	if (arg.args_count != 1) {
+		mii_ts = ERR_PTR(-EINVAL);
+		goto put_node;
+	}
+
+	mii_ts = register_mii_timestamper(arg.np, arg.args[0]);
 
-	return register_mii_timestamper(arg.np, arg.args[0]);
+put_node:
+	of_node_put(arg.np);
+	return mii_ts;
 }
 
 int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,