linux-stable.git/net/sunrpc, branch linux-6.11.y

sunrpc: fix one UAF issue caused by sunrpc kernel tcp socket

2024-12-05T12:54:33+00:00

[ Upstream commit 3f23f96528e8fcf8619895c4c916c52653892ec1 ]

BUG: KASAN: slab-use-after-free in tcp_write_timer_handler+0x156/0x3e0
Read of size 1 at addr ffff888111f322cd by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc4-dirty #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1
Call Trace:
 
 dump_stack_lvl+0x68/0xa0
 print_address_description.constprop.0+0x2c/0x3d0
 print_report+0xb4/0x270
 kasan_report+0xbd/0xf0
 tcp_write_timer_handler+0x156/0x3e0
 tcp_write_timer+0x66/0x170
 call_timer_fn+0xfb/0x1d0
 __run_timers+0x3f8/0x480
 run_timer_softirq+0x9b/0x100
 handle_softirqs+0x153/0x390
 __irq_exit_rcu+0x103/0x120
 irq_exit_rcu+0xe/0x20
 sysvec_apic_timer_interrupt+0x76/0x90
 
 
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90
 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 f8 25 00 fb f4  c3 cc cc cc
 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffffffa2007e28 EFLAGS: 00000242
RAX: 00000000000f3b31 RBX: 1ffffffff4400fc7 RCX: ffffffffa09c3196
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9f00590f
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed102360835d
R10: ffff88811b041aeb R11: 0000000000000001 R12: 0000000000000000
R13: ffffffffa202d7c0 R14: 0000000000000000 R15: 00000000000147d0
 default_idle_call+0x6b/0xa0
 cpuidle_idle_call+0x1af/0x1f0
 do_idle+0xbc/0x130
 cpu_startup_entry+0x33/0x40
 rest_init+0x11f/0x210
 start_kernel+0x39a/0x420
 x86_64_start_reservations+0x18/0x30
 x86_64_start_kernel+0x97/0xa0
 common_startup_64+0x13e/0x141
 

Allocated by task 595:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_slab_alloc+0x87/0x90
 kmem_cache_alloc_noprof+0x12b/0x3f0
 copy_net_ns+0x94/0x380
 create_new_namespaces+0x24c/0x500
 unshare_nsproxy_namespaces+0x75/0xf0
 ksys_unshare+0x24e/0x4f0
 __x64_sys_unshare+0x1f/0x30
 do_syscall_64+0x70/0x180
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 100:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 __kasan_slab_free+0x54/0x70
 kmem_cache_free+0x156/0x5d0
 cleanup_net+0x5d3/0x670
 process_one_work+0x776/0xa90
 worker_thread+0x2e2/0x560
 kthread+0x1a8/0x1f0
 ret_from_fork+0x34/0x60
 ret_from_fork_asm+0x1a/0x30

Reproduction script:

mkdir -p /mnt/nfsshare
mkdir -p /mnt/nfs/netns_1
mkfs.ext4 /dev/sdb
mount /dev/sdb /mnt/nfsshare
systemctl restart nfs-server
chmod 777 /mnt/nfsshare
exportfs -i -o rw,no_root_squash *:/mnt/nfsshare

ip netns add netns_1
ip link add name veth_1_peer type veth peer veth_1
ifconfig veth_1_peer 11.11.0.254 up
ip link set veth_1 netns netns_1
ip netns exec netns_1 ifconfig veth_1 11.11.0.1

ip netns exec netns_1 /root/iptables -A OUTPUT -d 11.11.0.254 -p tcp \
	--tcp-flags FIN FIN  -j DROP

(note: In my environment, a DESTROY_CLIENTID operation is always sent
 immediately, breaking the nfs tcp connection.)
ip netns exec netns_1 timeout -s 9 300 mount -t nfs -o proto=tcp,vers=4.1 \
	11.11.0.254:/mnt/nfsshare /mnt/nfs/netns_1

ip netns del netns_1

The reason here is that the tcp socket in netns_1 (nfs side) has been
shutdown and closed (done in xs_destroy), but the FIN message (with ack)
is discarded, and the nfsd side keeps sending retransmission messages.
As a result, when the tcp sock in netns_1 processes the received message,
it sends the message (FIN message) in the sending queue, and the tcp timer
is re-established. When the network namespace is deleted, the net structure
accessed by tcp's timer handler function causes problems.

To fix this problem, let's hold netns refcnt for the tcp kernel socket as
done in other modules. This is an ugly hack which can easily be backported
to earlier kernels. A proper fix which cleans up the interfaces will
follow, but may not be so easy to backport.

Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Signed-off-by: Liu Jian 
Acked-by: Jeff Layton 
Reviewed-by: Kuniyuki Iwashima 
Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

SUNRPC: timeout and cancel TLS handshake with -ETIMEDOUT

2024-12-05T12:54:32+00:00

[ Upstream commit d7bdd849ef1b681da03ac05ca0957b2cbe2d24b6 ]

We've noticed a situation where an unstable TCP connection can cause the
TLS handshake to timeout waiting for userspace to complete it.  When this
happens, we don't want to return from xs_tls_handshake_sync() with zero, as
this will cause the upper xprt to be set CONNECTED, and subsequent attempts
to transmit will be returned with -EPIPE.  The sunrpc machine does not
recover from this situation and will spin attempting to transmit.

The return value of tls_handshake_cancel() can be used to detect a race
with completion:

 * tls_handshake_cancel - cancel a pending handshake
 * Return values:
 *   %true - Uncompleted handshake request was canceled
 *   %false - Handshake request already completed or not found

If true, we do not want the upper xprt to be connected, so return
-ETIMEDOUT.  If false, its possible the handshake request was lost and
that may be the reason for our timeout.  Again we do not want the upper
xprt to be connected, so return -ETIMEDOUT.

Ensure that we alway return an error from xs_tls_handshake_sync() if we
call tls_handshake_cancel().

Signed-off-by: Benjamin Coddington 
Reviewed-by: Chuck Lever 
Fixes: 75eb6af7acdf ("SUNRPC: Add a TCP-with-TLS RPC transport class")
Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

sunrpc: clear XPRT_SOCK_UPD_TIMEOUT when reset transport

2024-12-05T12:54:32+00:00

[ Upstream commit 4db9ad82a6c823094da27de4825af693a3475d51 ]

Since transport->sock has been set to NULL during reset transport,
XPRT_SOCK_UPD_TIMEOUT also needs to be cleared. Otherwise, the
xs_tcp_set_socket_timeouts() may be triggered in xs_tcp_send_request()
to dereference the transport->sock that has been set to NULL.

Fixes: 7196dbb02ea0 ("SUNRPC: Allow changing of the TCP timeout parameters on the fly")
Signed-off-by: Li Lingfeng 
Signed-off-by: Liu Jian 
Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

SUNRPC: make sure cache entry active before cache_show

2024-12-05T12:54:26+00:00

commit 2862eee078a4d2d1f584e7f24fa50dddfa5f3471 upstream.

The function `c_show` was called with protection from RCU. This only
ensures that `cp` will not be freed. Therefore, the reference count for
`cp` can drop to zero, which will trigger a refcount use-after-free
warning when `cache_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `cp` remains active.

------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 7 PID: 822 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 7 UID: 0 PID: 822 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:refcount_warn_saturate+0xb1/0x120

Call Trace:
 
 c_show+0x2fc/0x380 [sunrpc]
 seq_read_iter+0x589/0x770
 seq_read+0x1e5/0x270
 proc_reg_read+0xe1/0x140
 vfs_read+0x125/0x530
 ksys_read+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Yang Erkun 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

svcrdma: fix miss destroy percpu_counter in svc_rdma_proc_init()

2024-12-05T12:53:54+00:00

[ Upstream commit ce89e742a4c12b20f09a43fec1b21db33f2166cd ]

There's issue as follows:
RPC: Registered rdma transport module.
RPC: Registered rdma backchannel transport module.
RPC: Unregistered rdma transport module.
RPC: Unregistered rdma backchannel transport module.
BUG: unable to handle page fault for address: fffffbfff80c609a
PGD 123fee067 P4D 123fee067 PUD 123fea067 PMD 10c624067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
RIP: 0010:percpu_counter_destroy_many+0xf7/0x2a0
Call Trace:
 
 __die+0x1f/0x70
 page_fault_oops+0x2cd/0x860
 spurious_kernel_fault+0x36/0x450
 do_kern_addr_fault+0xca/0x100
 exc_page_fault+0x128/0x150
 asm_exc_page_fault+0x26/0x30
 percpu_counter_destroy_many+0xf7/0x2a0
 mmdrop+0x209/0x350
 finish_task_switch.isra.0+0x481/0x840
 schedule_tail+0xe/0xd0
 ret_from_fork+0x23/0x80
 ret_from_fork_asm+0x1a/0x30
 

If register_sysctl() return NULL, then svc_rdma_proc_cleanup() will not
destroy the percpu counters which init in svc_rdma_proc_init().
If CONFIG_HOTPLUG_CPU is enabled, residual nodes may be in the
'percpu_counters' list. The above issue may occur once the module is
removed. If the CONFIG_HOTPLUG_CPU configuration is not enabled, memory
leakage occurs.
To solve above issue just destroy all percpu counters when
register_sysctl() return NULL.

Fixes: 1e7e55731628 ("svcrdma: Restore read and write stats")
Fixes: 22df5a22462e ("svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter")
Fixes: df971cd853c0 ("svcrdma: Convert rdma_stat_recv to a per-CPU counter")
Signed-off-by: Ye Bin 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin

svcrdma: Address an integer overflow

2024-12-05T12:53:51+00:00

[ Upstream commit 3c63d8946e578663b868cb9912dac616ea68bfd0 ]

Dan Carpenter reports:
> Commit 78147ca8b4a9 ("svcrdma: Add a "parsed chunk list" data
> structure") from Jun 22, 2020 (linux-next), leads to the following
> Smatch static checker warning:
>
>	net/sunrpc/xprtrdma/svc_rdma_recvfrom.c:498 xdr_check_write_chunk()
>	warn: potential user controlled sizeof overflow 'segcount * 4 * 4'
>
> net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
>     488 static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt)
>     489 {
>     490         u32 segcount;
>     491         __be32 *p;
>     492
>     493         if (xdr_stream_decode_u32(&rctxt->rc_stream, &segcount))
>                                                               ^^^^^^^^
>
>     494                 return false;
>     495
>     496         /* A bogus segcount causes this buffer overflow check to fail. */
>     497         p = xdr_inline_decode(&rctxt->rc_stream,
> --> 498                               segcount * rpcrdma_segment_maxsz * sizeof(*p));
>
>
> segcount is an untrusted u32.  On 32bit systems anything >= SIZE_MAX / 16 will
> have an integer overflow and some those values will be accepted by
> xdr_inline_decode().

Reported-by: Dan Carpenter 
Fixes: 78147ca8b4a9 ("svcrdma: Add a "parsed chunk list" data structure")
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin

sunrpc: handle -ENOTCONN in xs_tcp_setup_socket()

2024-11-14T12:20:57+00:00

[ Upstream commit 10f0740234f0b157b41bdc7e9c3555a9b86c1599 ]

xs_tcp_finish_connecting() can return -ENOTCONN but the switch statement
in xs_tcp_setup_socket() treats that as an unhandled error.

If we treat it as a known error it would propagate back to
call_connect_status() which does handle that error code.  This appears
to be the intention of the commit (given below) which added -ENOTCONN as
a return status for xs_tcp_finish_connecting().

So add -ENOTCONN to the switch statement as an error to pass through to
the caller.

Link: https://bugzilla.suse.com/show_bug.cgi?id=1231050
Link: https://access.redhat.com/discussions/3434091
Fixes: 01d37c428ae0 ("SUNRPC: xprt_connect() don't abort the task if the transport isn't bound")
Signed-off-by: NeilBrown 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Anna Schumaker 
Signed-off-by: Sasha Levin

rpcrdma: Always release the rpcrdma_device's xa_array

2024-11-08T15:30:52+00:00

[ Upstream commit 63a81588cd2025e75fbaf30b65930b76825c456f ]

Dai pointed out that the xa_init_flags() in rpcrdma_add_one() needs
to have a matching xa_destroy() in rpcrdma_remove_one() to release
underlying memory that the xarray might have accrued during
operation.

Reported-by: Dai Ngo 
Fixes: 7e86845a0346 ("rpcrdma: Implement generic device removal")
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin

sunrpc: change sp_nrthreads from atomic_t to unsigned int.

2024-10-10T10:04:14+00:00

[ Upstream commit 60749cbe3d8ae572a6c7dda675de3e8b25797a18 ]

sp_nrthreads is only ever accessed under the service mutex
  nlmsvc_mutex nfs_callback_mutex nfsd_mutex
so these is no need for it to be an atomic_t.

The fact that all code using it is single-threaded means that we can
simplify svc_pool_victim and remove the temporary elevation of
sp_nrthreads.

Signed-off-by: NeilBrown 
Signed-off-by: Chuck Lever 
Stable-dep-of: aadc3bbea163 ("NFSD: Limit the number of concurrent async COPY operations")
Signed-off-by: Sasha Levin

rpcrdma: Trace connection registration and unregistration

2024-08-19T15:50:41+00:00

These new trace points record xarray indices and the time of
endpoint registration and unregistration, to co-ordinate with
device removal events.

Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker