| Message ID | 20250217191129.19967-1-kuniyu@amazon.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | net: Fix race of rtnl_net_lock(dev_net(dev)). | expand |
Hello: This series was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Mon, 17 Feb 2025 11:11:26 -0800 you wrote: > Yael Chemla reported that commit 7fb1073300a2 ("net: Hold rtnl_net_lock() > in (un)?register_netdevice_notifier_dev_net().") started to trigger KASAN's > use-after-free splat. > > The problem is that dev_net(dev) fetched before rtnl_net_lock() might be > different after rtnl_net_lock(). > > [...] Here is the summary with links: - [v5,net,1/3] net: Add net_passive_inc() and net_passive_dec(). https://git.kernel.org/netdev/net/c/e57a6320215c - [v5,net,2/3] net: Fix dev_net(dev) race in unregister_netdevice_notifier_dev_net(). https://git.kernel.org/netdev/net/c/65161fb544aa - [v5,net,3/3] dev: Use rtnl_net_dev_lock() in unregister_netdev(). https://git.kernel.org/netdev/net/c/d4c6bfc83936 You are awesome, thank you!
Yael Chemla reported that commit 7fb1073300a2 ("net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_dev_net().") started to trigger KASAN's use-after-free splat. The problem is that dev_net(dev) fetched before rtnl_net_lock() might be different after rtnl_net_lock(). The patch 2 fixes the issue by checking dev_net(dev) after rtnl_net_lock(), and the patch 3 fixes the same potential issue that would emerge once RTNL is removed. Changes: v5: * Use do-while loop instead of goto v4: https://lore.kernel.org/netdev/20250212064206.18159-1-kuniyu@amazon.com/ * Add patch 1 * Fix build failure for !CONFIG_NET_NS in patch 2 v3: https://lore.kernel.org/netdev/20250211051217.12613-1-kuniyu@amazon.com/ * Bump net->passive instead of maybe_get_net() * Remove msleep(1) loop * Use rcu_access_pointer() instead of rcu_read_lock(). v2: https://lore.kernel.org/netdev/20250207044251.65421-1-kuniyu@amazon.com/ * Use dev_net_rcu() * Use msleep(1) instead of cond_resched() after maybe_get_net() * Remove cond_resched() after net_eq() check v1: https://lore.kernel.org/netdev/20250130232435.43622-1-kuniyu@amazon.com/ Kuniyuki Iwashima (3): net: Add net_passive_inc() and net_passive_dec(). net: Fix dev_net(dev) race in unregister_netdevice_notifier_dev_net(). dev: Use rtnl_net_dev_lock() in unregister_netdev(). include/net/net_namespace.h | 11 ++++++++ net/core/dev.c | 54 +++++++++++++++++++++++++++++++------ net/core/net_namespace.c | 8 +++--- 3 files changed, 61 insertions(+), 12 deletions(-)