Merge branch 'netdevsim-psp-fix-init-and-uninit-bugs'

Daniel Zahka says:

====================
netdevsim: psp: fix init and uninit bugs

This series has three fixes. The first is a straightforward NULL
pointer dereference that is reachable by creating and destroying some
vfs on a kernel with INET_PSP enabled.

The last two patches deal with nsim_psp_rereg_write(), which is a
debugfs handler that reregisters netdevsim's psp_dev without
aquiescing and disabling tx/rx processing. This was added to enable
some tests in psp.py where a psp device is unregistered while it still
referenced by tcp socket state.

There are two issues with this code:
1. Calls to nsim_psp_uninit() are not properly serialized
2. netdevsim's psp_dev refcount can be released while nsim_do_psp() is
   reading from it.
====================

Link: https://patch.msgid.link/20260505-psd-rcu-v1-0-a8f69ec1ab96@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 7e129dddbbe7..d909c4160ea1 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -120,7 +120,9 @@ struct netdevsim {
 		u64_stats_t tx_packets;
 		u64_stats_t tx_bytes;
 		struct u64_stats_sync syncp;
-		struct psp_dev *dev;
+		struct psp_dev __rcu *dev;
+		struct dentry *rereg;
+		struct mutex rereg_lock;
 		u32 spi;
 		u32 assoc_cnt;
 	} psp;