Unverified Commit 9158c6bb authored by Zhen Ni's avatar Zhen Ni Committed by Christian Brauner
Browse files

afs: Fix potential null pointer dereference in afs_put_server 



afs_put_server() accessed server->debug_id before the NULL check, which
could lead to a null pointer dereference. Move the debug_id assignment,
ensuring we never dereference a NULL server pointer.

Fixes: 2757a4dc ("afs: Fix access after dec in put functions")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarZhen Ni <zhen.ni@easystack.cn>
Acked-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeffrey Altman <jaltman@auristor.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 66d938e8

fs/afs/server.c

+2 −1
Original line number Diff line number Diff line
@@ -331,13 +331,14 @@ struct afs_server *afs_use_server(struct afs_server *server, bool activate, 
void afs_put_server(struct afs_net *net, struct afs_server *server,

		    enum afs_server_trace reason)

{

	unsigned int a, debug_id = server->debug_id;

	unsigned int a, debug_id;

	bool zero;

	int r;



	if (!server)

		return;



	debug_id = server->debug_id;

	a = atomic_read(&server->active);

	zero = __refcount_dec_and_test(&server->ref, &r);

	trace_afs_server(debug_id, r - 1, a, reason);