linux.git/net/sunrpc/sysfs.c, branch v6.0.6

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

SUNRPC add xps_nunique_destaddr_xprts to xprt_switch_info in sysfs

2021-08-27T20:37:03+00:00

In sysfs's xprt_switch_info attribute also display the value of
number of transports with unique destination addresses for this
xprt_switch.

Signed-off-by: Olga Kornievskaia 
Signed-off-by: Anna Schumaker