kernel/linux.git/net/sunrpc/sysfs.c, branch v6.1.168

SUNRPC: Fix null-ptr-deref when xps sysfs alloc failed

2022-10-27T19:52:10+00:00

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: 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 Signed-off-by: Anna Schumaker

net/sunrpc: fix potential memory leaks in rpc_sysfs_xprt_state_change()

2022-08-12T10:21:28+00:00

The issue happens on some error handling paths. When the function fails to grab the object `xprt`, it simply returns 0, forgetting to decrease the reference count of another object `xps`, which is increased by rpc_sysfs_xprt_kobj_get_xprt_switch(), causing refcount leaks. Also, the function forgets to check whether `xps` is valid before using it, which may result in NULL-dereferencing issues. Fix it by adding proper error handling code when either `xprt` or `xps` is NULL. Fixes: 5b7eb78486cd ("SUNRPC: take a xprt offline using sysfs") Signed-off-by: Xin Xiong Signed-off-by: Xin Tan Signed-off-by: David S. Miller

SUNRPC expose functions for offline remote xprt functionality

2022-07-25T14:06:04+00:00

Re-arrange the code that make offline transport and delete transport callable functions. Signed-off-by: Olga Kornievskaia Signed-off-by: Trond Myklebust

SUNRPC: Don't return error values in sysfs read of closed files

2022-03-25T17:24:12+00:00

Instead of returning an error value, which ends up being the return value for the read() system call, it is more elegant to simply return the error as a string value. Signed-off-by: Trond Myklebust

SUNRPC: Do not dereference non-socket transports in sysfs

2022-03-25T17:22:58+00:00

Do not cast the struct xprt to a sock_xprt unless we know it is a UDP or TCP transport. Otherwise the call to lock the mutex will scribble over whatever structure is actually there. This has been seen to cause hard system lockups when the underlying transport was RDMA. Fixes: b49ea673e119 ("SUNRPC: lock against ->sock changing during sysfs read") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust

SUNRPC: lock against ->sock changing during sysfs read

2022-02-08T14:14:26+00:00

->sock can be set to NULL asynchronously unless ->recv_mutex is held. So it is important to hold that mutex. Otherwise a sysfs read can trigger an oops. Commit 17f09d3f619a ("SUNRPC: Check if the xprt is connected before handling sysfs reads") appears to attempt to fix this problem, but it only narrows the race window. Fixes: 17f09d3f619a ("SUNRPC: Check if the xprt is connected before handling sysfs reads") Fixes: a8482488a7d6 ("SUNRPC query transport's source port") Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker

sunrpc: Fix potential race conditions in rpc_sysfs_xprt_state_change()

2022-01-13T14:36:58+00:00

We need to use test_and_set_bit() when changing xprt state flags to avoid potentially getting xps->xps_nactive out of sync. Signed-off-by: Anna Schumaker

net/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change

2022-01-13T14:36:58+00:00

The refcount leak issues take place in an error handling path. When the 3rd argument buf doesn't match with "offline", "online" or "remove", the function simply returns -EINVAL and forgets to decrease the reference count of a rpc_xprt object and a rpc_xprt_switch object increased by rpc_sysfs_xprt_kobj_get_xprt() and rpc_sysfs_xprt_kobj_get_xprt_switch(), causing reference count leaks of both unused objects. Fix this issue by jumping to the error handling path labelled with out_put when buf matches none of "offline", "online" or "remove". Signed-off-by: Xiyu Yang Signed-off-by: Xin Xiong Signed-off-by: Xin Tan Signed-off-by: Anna Schumaker

SUNRPC: use default_groups in kobj_type

2022-01-06T19:00:21+00:00

There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the sunrpc sysfs code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Cc: "J. Bruce Fields" Cc: Chuck Lever Cc: Trond Myklebust Cc: Anna Schumaker Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Anna Schumaker

SUNRPC: Check if the xprt is connected before handling sysfs reads

2021-11-04T23:43:29+00:00

xprts don't immediately reconnect when changing the "dstaddr" property, instead this gets handled the next time an operation uses the transport. This could lead to NULL pointer dereferences when trying to read sysfs files between the disconnect and reconnect operations. Fix this by returning an error if the xprt is not connected. Signed-off-by: Anna Schumaker Signed-off-by: Trond Myklebust