There is a null-ptr-deref when xps sysfs alloc failed:
BUG: KASAN: null-ptr-deref in sysfs_do_create_link_sd+0x40/0xd0
Read of size 8 at addr 0000000000000030 by task gssproxy/457
CPU: 5 PID: 457 Comm: gssproxy Not tainted 6.0.0-09040-g02357b27ee03 #9
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
kasan_report+0xa3/0x120
sysfs_do_create_link_sd+0x40/0xd0
rpc_sysfs_client_setup+0x161/0x1b0
rpc_new_client+0x3fc/0x6e0
rpc_create_xprt+0x71/0x220
rpc_create+0x1d4/0x350
gssp_rpc_create+0xc3/0x160
set_gssp_clnt+0xbc/0x140
write_gssp+0x116/0x1a0
proc_reg_write+0xd6/0x130
vfs_write+0x177/0x690
ksys_write+0xb9/0x150
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
When the xprt_switch sysfs alloc failed, should not add xprt and
switch sysfs to it, otherwise, maybe null-ptr-deref; also initialize
the 'xps_sysfs' to NULL to avoid oops when destroy it.
Fixes: 2a338a543163 ("sunrpc: add a symlink from rpc-client directory to the xprt_switch")
Fixes: d408ebe04ac5 ("sunrpc: add add sysfs directory per xprt under each xprt_switch")
Fixes: baea99445dd4 ("sunrpc: add xprt_switch direcotry to sunrpc's sysfs")
Signed-off-by: Zhang Xiaoxu <[email protected]>
---
net/sunrpc/sysfs.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index c65c90ad626a..c1f559892ae8 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -518,13 +518,16 @@ void rpc_sysfs_client_setup(struct rpc_clnt *clnt,
struct net *net)
{
struct rpc_sysfs_client *rpc_client;
+ struct rpc_sysfs_xprt_switch *xswitch =
+ (struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs;
+
+ if (!xswitch)
+ return;
rpc_client = rpc_sysfs_client_alloc(rpc_sunrpc_client_kobj,
net, clnt->cl_clid);
if (rpc_client) {
char name[] = "switch";
- struct rpc_sysfs_xprt_switch *xswitch =
- (struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs;
int ret;
clnt->cl_sysfs = rpc_client;
@@ -558,6 +561,8 @@ void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch,
rpc_xprt_switch->xprt_switch = xprt_switch;
rpc_xprt_switch->xprt = xprt;
kobject_uevent(&rpc_xprt_switch->kobject, KOBJ_ADD);
+ } else {
+ xprt_switch->xps_sysfs = NULL;
}
}
@@ -569,6 +574,9 @@ void rpc_sysfs_xprt_setup(struct rpc_xprt_switch *xprt_switch,
struct rpc_sysfs_xprt_switch *switch_obj =
(struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs;
+ if (!switch_obj)
+ return;
+
rpc_xprt = rpc_sysfs_xprt_alloc(&switch_obj->kobject, xprt, gfp_flags);
if (rpc_xprt) {
xprt->xprt_sysfs = rpc_xprt;
--
2.31.1