mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Munehisa Kamata
b15bd8cb37
Since commitd05d7f4079("Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block") and3fc9d69093("Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block"), blkfront_resume() has been using an index for iterating ring_info to check request when iterating blk_shadow in an inner loop. This seems to have been accidentally introduced during the massive rewrite of the block layer macros in the commits. This may cause crash like this: [11798.057074] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 [11798.058832] IP: [<ffffffff814411fa>] blkfront_resume+0x10a/0x610 .... [11798.061063] Call Trace: [11798.061063] [<ffffffff8139ce93>] xenbus_dev_resume+0x53/0x140 [11798.061063] [<ffffffff8139ce40>] ? xenbus_dev_probe+0x150/0x150 [11798.061063] [<ffffffff813f359e>] dpm_run_callback+0x3e/0x110 [11798.061063] [<ffffffff813f3a08>] device_resume+0x88/0x190 [11798.061063] [<ffffffff813f4cc0>] dpm_resume+0x100/0x2d0 [11798.061063] [<ffffffff813f5221>] dpm_resume_end+0x11/0x20 [11798.061063] [<ffffffff813950a8>] do_suspend+0xe8/0x1a0 [11798.061063] [<ffffffff813954bd>] shutdown_handler+0xfd/0x130 [11798.061063] [<ffffffff8139aba0>] ? split+0x110/0x110 [11798.061063] [<ffffffff8139ac26>] xenwatch_thread+0x86/0x120 [11798.061063] [<ffffffff810b4570>] ? prepare_to_wait_event+0x110/0x110 [11798.061063] [<ffffffff8108fe57>] kthread+0xd7/0xf0 [11798.061063] [<ffffffff811da811>] ? kfree+0x121/0x170 [11798.061063] [<ffffffff8108fd80>] ? kthread_park+0x60/0x60 [11798.061063] [<ffffffff810863b0>] ? call_usermodehelper_exec_work+0xb0/0xb0 [11798.061063] [<ffffffff810864ea>] ? call_usermodehelper_exec_async+0x13a/0x140 [11798.061063] [<ffffffff81534a45>] ret_from_fork+0x25/0x30 Use the right index in the inner loop. Fixes:d05d7f4079("Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block") Fixes:3fc9d69093("Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block") Signed-off-by: Munehisa Kamata <kamatam@amazon.com> Reviewed-by: Thomas Friebel <friebelt@amazon.de> Reviewed-by: Eduardo Valentin <eduval@amazon.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Roger Pau Monne <roger.pau@citrix.com> Cc: xen-devel@lists.xenproject.org Cc: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.