Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752856AbbDTXNT (ORCPT ); Mon, 20 Apr 2015 19:13:19 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:35711 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbbDTXNQ (ORCPT ); Mon, 20 Apr 2015 19:13:16 -0400 X-Sasl-enc: XPAaQjmorslMbWr3+OZUF+rDLy/Cq5YnRqLOOUvKWmo3 1429571593 From: Sergei Zviagintsev To: Greg Kroah-Hartman , Daniel Mack , David Herrmann , Djalal Harouni Cc: linux-kernel@vger.kernel.org, Sergei Zviagintsev Subject: [PATCH] kdbus: pool: use __vfs_read() Date: Tue, 21 Apr 2015 02:12:18 +0300 Message-Id: <1429571538-32072-1-git-send-email-sergei@s15v.net> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3800 Lines: 74 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] [] ? kdbus_pool_slice_copy+0x127/0x200 [kdbus] [ 1167.150771] [] ? kdbus_pool_slice_copy+0xd/0x200 [kdbus] [ 1167.150771] [] kdbus_queue_entry_move+0xaa/0x180 [kdbus] [ 1167.150771] [] kdbus_conn_move_messages+0x1e4/0x2c0 [kdbus] [ 1167.150771] [] kdbus_name_acquire+0x31e/0x390 [kdbus] [ 1167.150771] [] kdbus_cmd_name_acquire+0x125/0x130 [kdbus] [ 1167.150771] [] kdbus_handle_ioctl+0x4ed/0x610 [kdbus] [ 1167.150771] [] do_vfs_ioctl+0x2e0/0x4e0 [ 1167.150771] [] ? preempt_schedule_common+0x1f/0x3f [ 1167.150771] [] SyS_ioctl+0x3c/0x80 [ 1167.150771] [] system_call_fastpath+0x12/0x71 [ 1167.150771] Code: Bad RIP value. [ 1167.150771] RIP [< (null)>] (null) [ 1167.150771] RSP [ 1167.150771] CR2: 0000000000000000 [ 1167.168756] ---[ end trace a676bcfa75db5a96 ]--- Use __vfs_read() instead. Signed-off-by: Sergei Zviagintsev --- ipc/kdbus/pool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/kdbus/pool.c b/ipc/kdbus/pool.c index 139bb77056b3..45dcdea505f4 100644 --- a/ipc/kdbus/pool.c +++ b/ipc/kdbus/pool.c @@ -675,7 +675,7 @@ int kdbus_pool_slice_copy(const struct kdbus_pool_slice *slice_dst, } kaddr = (char __force __user *)kmap(page) + page_off; - n_read = f_src->f_op->read(f_src, kaddr, copy_len, &off_src); + n_read = __vfs_read(f_src, kaddr, copy_len, &off_src); kunmap(page); mark_page_accessed(page); flush_dcache_page(page); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/