kernel/git/stable/linux.git/net/rds/send.c, branch linux-4.17.y

RDS: RDMA: Fix the NULL-ptr deref in rds_ib_get_mr

2018-08-03T05:48:05+00:00

[ Upstream commit 9e630bcb7701f94dbd729fe57d37c089c763ad9f ] Registration of a memory region(MR) through FRMR/fastreg(unlike FMR) needs a connection/qp. With a proxy qp, this dependency on connection will be removed, but that needs more infrastructure patches, which is a work in progress. As an intermediate fix, the get_mr returns EOPNOTSUPP when connection details are not populated. The MR registration through sendmsg() will continue to work even with fast registration, since connection in this case is formed upfront. This patch fixes the following crash: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Modules linked in: CPU: 1 PID: 4244 Comm: syzkaller468044 Not tainted 4.16.0-rc6+ #361 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rds_ib_get_mr+0x5c/0x230 net/rds/ib_rdma.c:544 RSP: 0018:ffff8801b059f890 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8801b07e1300 RCX: ffffffff8562d96e RDX: 000000000000000d RSI: 0000000000000001 RDI: 0000000000000068 RBP: ffff8801b059f8b8 R08: ffffed0036274244 R09: ffff8801b13a1200 R10: 0000000000000004 R11: ffffed0036274243 R12: ffff8801b13a1200 R13: 0000000000000001 R14: ffff8801ca09fa9c R15: 0000000000000000 FS: 00007f4d050af700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4d050aee78 CR3: 00000001b0d9b006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __rds_rdma_map+0x710/0x1050 net/rds/rdma.c:271 rds_get_mr_for_dest+0x1d4/0x2c0 net/rds/rdma.c:357 rds_setsockopt+0x6cc/0x980 net/rds/af_rds.c:347 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4456d9 RSP: 002b:00007f4d050aedb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 00000000004456d9 RDX: 0000000000000007 RSI: 0000000000000114 RDI: 0000000000000004 RBP: 00000000006dac38 R08: 00000000000000a0 R09: 0000000000000000 R10: 0000000020000380 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffbfb36d6f R14: 00007f4d050af9c0 R15: 0000000000000005 Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 cc 01 00 00 4c 8b bb 80 04 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7f 68 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9c 01 00 00 4d 8b 7f 68 48 b8 00 00 00 00 00 RIP: rds_ib_get_mr+0x5c/0x230 net/rds/ib_rdma.c:544 RSP: ffff8801b059f890 ---[ end trace 7e1cea13b85473b0 ]--- Reported-by: syzbot+b51c77ef956678a65834@syzkaller.appspotmail.com Signed-off-by: Santosh Shilimkar Signed-off-by: Avinash Repaka Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

rds: MP-RDS may use an invalid c_path

2018-04-11T14:24:01+00:00

rds_sendmsg() calls rds_send_mprds_hash() to find a c_path to use to send a message. Suppose the RDS connection is not yet up. In rds_send_mprds_hash(), it does if (conn->c_npaths == 0) wait_event_interruptible(conn->c_hs_waitq, (conn->c_npaths != 0)); If it is interrupted before the connection is set up, rds_send_mprds_hash() will return a non-zero hash value. Hence rds_sendmsg() will use a non-zero c_path to send the message. But if the RDS connection ends up to be non-MP capable, the message will be lost as only the zero c_path can be used. Signed-off-by: Ka-Cheong Poon Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

rds: rds_msg_zcopy should return error of null rm->data.op_mmp_znotifier

2018-02-23T17:30:52+00:00

if either or both of MSG_ZEROCOPY and SOCK_ZEROCOPY have not been specified, the rm->data.op_mmp_znotifier allocation will be skipped. In this case, it is invalid ot pass down a cmsghdr with RDS_CMSG_ZCOPY_COOKIE, so return EINVAL from rds_msg_zcopy for this case. Reported-by: syzbot+f893ae7bb2f6456dfbc3@syzkaller.appspotmail.com Fixes: 0cebaccef3ac ("rds: zerocopy Tx support.") Signed-off-by: Sowmini Varadhan Acked-by: Willem de Bruijn Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

rds: send: mark expected switch fall-through in rds_rm_size

2018-02-21T19:18:18+00:00

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Addresses-Coverity-ID: 1465362 ("Missing break in switch") Signed-off-by: Gustavo A. R. Silva Acked-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

rds: zerocopy Tx support.

2018-02-16T21:04:17+00:00

If the MSG_ZEROCOPY flag is specified with rds_sendmsg(), and, if the SO_ZEROCOPY socket option has been set on the PF_RDS socket, application pages sent down with rds_sendmsg() are pinned. The pinning uses the accounting infrastructure added by Commit a91dbff551a6 ("sock: ulimit on MSG_ZEROCOPY pages") The payload bytes in the message may not be modified for the duration that the message has been pinned. A multi-threaded application using this infrastructure may thus need to be notified about send-completion so that it can free/reuse the buffers passed to rds_sendmsg(). Notification of send-completion will identify each message-buffer by a cookie that the application must specify as ancillary data to rds_sendmsg(). The ancillary data in this case has cmsg_level == SOL_RDS and cmsg_type == RDS_CMSG_ZCOPY_COOKIE. Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

rds: hold a sock ref from rds_message to the rds_sock

2018-02-16T21:04:16+00:00

The existing model holds a reference from the rds_sock to the rds_message, but the rds_message does not itself hold a sock_put() on the rds_sock. Instead the m_rs field in the rds_message is assigned when the message is queued on the sock, and nulled when the message is dequeued from the sock. We want to be able to notify userspace when the rds_message is actually freed (from rds_message_purge(), after the refcounts to the rds_message go to 0). At the time that rds_message_purge() is called, the message is no longer on the rds_sock retransmit queue. Thus the explicit reference for the m_rs is needed to send a notification that will signal to userspace that it is now safe to free/reuse any pages that may have been pinned down for zerocopy. This patch manages the m_rs assignment in the rds_message with the necessary refcount book-keeping. Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

rds: tcp: use rds_destroy_pending() to synchronize netns/module teardown and rds connection/workq management

2018-02-08T20:23:52+00:00

An rds_connection can get added during netns deletion between lines 528 and 529 of 506 static void rds_tcp_kill_sock(struct net *net) : /* code to pull out all the rds_connections that should be destroyed */ : 528 spin_unlock_irq(&rds_tcp_conn_lock); 529 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) 530 rds_conn_destroy(tc->t_cpath->cp_conn); Such an rds_connection would miss out the rds_conn_destroy() loop (that cancels all pending work) and (if it was scheduled after netns deletion) could trigger the use-after-free. A similar race-window exists for the module unload path in rds_tcp_exit -> rds_tcp_destroy_conns Concurrency with netns deletion (rds_tcp_kill_sock()) must be handled by checking check_net() before enqueuing new work or adding new connections. Concurrency with module-unload is handled by maintaining a module specific flag that is set at the start of the module exit function, and must be checked before enqueuing new work or adding new connections. This commit refactors existing RDS_DESTROY_PENDING checks added by commit 3db6e0d172c9 ("rds: use RCU to synchronize work-enqueue with connection teardown") and consolidates all the concurrency checks listed above into the function rds_destroy_pending(). Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

rds: use RCU to synchronize work-enqueue with connection teardown

2018-01-05T18:39:18+00:00

rds_sendmsg() can enqueue work on cp_send_w from process context, but it should not enqueue this work if connection teardown has commenced (else we risk enquing work after rds_conn_path_destroy() has assumed that all work has been cancelled/flushed). Similarly some other functions like rds_cong_queue_updates and rds_tcp_data_ready are called in softirq context, and may end up enqueuing work on rds_wq after rds_conn_path_destroy() has assumed that all workqs are quiesced. Check the RDS_DESTROY_PENDING bit and use rcu synchronization to avoid all these races. Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

RDS: Check cmsg_len before dereferencing CMSG_DATA

2017-12-27T15:37:23+00:00

RDS currently doesn't check if the length of the control message is large enough to hold the required data, before dereferencing the control message data. This results in following crash: BUG: KASAN: stack-out-of-bounds in rds_rdma_bytes net/rds/send.c:1013 [inline] BUG: KASAN: stack-out-of-bounds in rds_sendmsg+0x1f02/0x1f90 net/rds/send.c:1066 Read of size 8 at addr ffff8801c928fb70 by task syzkaller455006/3157 CPU: 0 PID: 3157 Comm: syzkaller455006 Not tainted 4.15.0-rc3+ #161 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 rds_rdma_bytes net/rds/send.c:1013 [inline] rds_sendmsg+0x1f02/0x1f90 net/rds/send.c:1066 sock_sendmsg_nosec net/socket.c:628 [inline] sock_sendmsg+0xca/0x110 net/socket.c:638 ___sys_sendmsg+0x320/0x8b0 net/socket.c:2018 __sys_sendmmsg+0x1ee/0x620 net/socket.c:2108 SYSC_sendmmsg net/socket.c:2139 [inline] SyS_sendmmsg+0x35/0x60 net/socket.c:2134 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x43fe49 RSP: 002b:00007fffbe244ad8 EFLAGS: 00000217 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fe49 RDX: 0000000000000001 RSI: 000000002020c000 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004017b0 R13: 0000000000401840 R14: 0000000000000000 R15: 0000000000000000 To fix this, we verify that the cmsg_len is large enough to hold the data to be read, before proceeding further. Reported-by: syzbot Signed-off-by: Avinash Repaka Acked-by: Santosh Shilimkar Reviewed-by: Yuval Shaia Signed-off-by: David S. Miller

rds: Fix incorrect statistics counting

2017-09-08T03:07:13+00:00

In rds_send_xmit() there is logic to batch the sends. However, if another thread has acquired the lock and has incremented the send_gen, it is considered a race and we yield. The code incrementing the s_send_lock_queue_raced statistics counter did not count this event correctly. This commit counts the race condition correctly. Changes from v1: - Removed check for *someone_on_xmit()* - Fixed incorrect indentation Signed-off-by: Håkon Bugge Reviewed-by: Knut Omang Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller