kdbus: pool: use __vfs_read()
After commit
5d5d56897530 ("make new_sync_{read,write}() static")
->read() cannot be called directly.
kdbus_pool_slice_copy() leads to oops, which can be reproduced by
launching tools/testing/selftests/kdbus/kdbus-test -t message-quota:
[ 1167.146793] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 1167.147554] IP: [< (null)>] (null)
[ 1167.148670] PGD
3a9dd067 PUD
3a841067 PMD 0
[ 1167.149611] Oops: 0010 [#1] SMP
[ 1167.150088] Modules linked in: nfsv3 nfs kdbus lockd grace sunrpc
[ 1167.150771] CPU: 0 PID: 518 Comm: kdbus-test Not tainted 4.0.0-next-
20150420-kdbus #62
[ 1167.150771] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1167.150771] task:
ffff88003daed120 ti:
ffff88003a800000 task.ti:
ffff88003a800000
[ 1167.150771] RIP: 0010:[<
0000000000000000>] [< (null)>] (null)
[ 1167.150771] RSP: 0018:
ffff88003a803bc0 EFLAGS:
00010286
[ 1167.150771] RAX:
ffff8800377fb000 RBX:
00000000000201e8 RCX:
ffff88003a803c00
[ 1167.150771] RDX:
0000000000000b40 RSI:
ffff8800377fb4c0 RDI:
ffff88003d815700
[ 1167.150771] RBP:
ffff88003a803c48 R08:
ffffffff8139e380 R09:
ffff880039d80490
[ 1167.150771] R10:
ffff88003a803a90 R11:
00000000000004c0 R12:
00000000002a24c0
[ 1167.150771] R13:
0000000000000b40 R14:
ffff88003d815700 R15:
ffffffff8139e460
[ 1167.150771] FS:
00007f41dccd4740(0000) GS:
ffff88003fc00000(0000) knlGS:
0000000000000000
[ 1167.150771] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 1167.150771] CR2:
0000000000000000 CR3:
000000003ccdf000 CR4:
00000000000007b0
[ 1167.150771] Stack:
[ 1167.150771]
ffffffffa0065497 ffff88003a803c10 00007ffffffff000 ffff88003aaa67c0
[ 1167.150771]
00000000000004c0 ffff88003aaa6870 ffff88003ca83300 ffffffffa006537d
[ 1167.150771]
00000000000201e8 ffffea0000ddfec0 ffff88003a803c20 0000000000000018
[ 1167.150771] Call Trace:
[ 1167.150771] [<
ffffffffa0065497>] ? kdbus_pool_slice_copy+0x127/0x200 [kdbus]
[ 1167.150771] [<
ffffffffa006537d>] ? kdbus_pool_slice_copy+0xd/0x200 [kdbus]
[ 1167.150771] [<
ffffffffa006670a>] kdbus_queue_entry_move+0xaa/0x180 [kdbus]
[ 1167.150771] [<
ffffffffa0059e64>] kdbus_conn_move_messages+0x1e4/0x2c0 [kdbus]
[ 1167.150771] [<
ffffffffa006234e>] kdbus_name_acquire+0x31e/0x390 [kdbus]
[ 1167.150771] [<
ffffffffa00625c5>] kdbus_cmd_name_acquire+0x125/0x130 [kdbus]
[ 1167.150771] [<
ffffffffa005db5d>] kdbus_handle_ioctl+0x4ed/0x610 [kdbus]
[ 1167.150771] [<
ffffffff811040e0>] do_vfs_ioctl+0x2e0/0x4e0
[ 1167.150771] [<
ffffffff81389750>] ? preempt_schedule_common+0x1f/0x3f
[ 1167.150771] [<
ffffffff8110431c>] SyS_ioctl+0x3c/0x80
[ 1167.150771] [<
ffffffff8138c36e>] system_call_fastpath+0x12/0x71
[ 1167.150771] Code: Bad RIP value.
[ 1167.150771] RIP [< (null)>] (null)
[ 1167.150771] RSP <
ffff88003a803bc0>
[ 1167.150771] CR2:
0000000000000000
[ 1167.168756] ---[ end trace
a676bcfa75db5a96 ]---
Use __vfs_read() instead.
Signed-off-by: Sergei Zviagintsev <sergei@s15v.net>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>