Since commit d05d7f40791c ("Merge branch 'for-4.8/core' of
git://git.kernel.dk/linux-block") and 3fc9d690936f ("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: d05d7f40791c ("Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block")
Fixes: 3fc9d690936f ("Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block")
Signed-off-by: Munehisa Kamata <[email protected]>
Reviewed-by: Thomas Friebel <[email protected]>
Reviewed-by: Eduardo Valentin <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Roger Pau Monne <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/block/xen-blkfront.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 98e34e4c62b8..2468c28d4771 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2075,9 +2075,9 @@ static int blkfront_resume(struct xenbus_device *dev)
/*
* Get the bios in the request so we can re-queue them.
*/
- if (req_op(shadow[i].request) == REQ_OP_FLUSH ||
- req_op(shadow[i].request) == REQ_OP_DISCARD ||
- req_op(shadow[i].request) == REQ_OP_SECURE_ERASE ||
+ if (req_op(shadow[j].request) == REQ_OP_FLUSH ||
+ req_op(shadow[j].request) == REQ_OP_DISCARD ||
+ req_op(shadow[j].request) == REQ_OP_SECURE_ERASE ||
shadow[j].request->cmd_flags & REQ_FUA) {
/*
* Flush operations don't contain bios, so
--
2.13.0
On 08/09/2017 06:31 PM, Munehisa Kamata wrote:
> Since commit d05d7f40791c ("Merge branch 'for-4.8/core' of
> git://git.kernel.dk/linux-block") and 3fc9d690936f ("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: d05d7f40791c ("Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block")
> Fixes: 3fc9d690936f ("Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block")
> Signed-off-by: Munehisa Kamata <[email protected]>
> Reviewed-by: Thomas Friebel <[email protected]>
> Reviewed-by: Eduardo Valentin <[email protected]>
> Cc: Boris Ostrovsky <[email protected]>
> Cc: Juergen Gross <[email protected]>
> Cc: Konrad Rzeszutek Wilk <[email protected]>
> Cc: Roger Pau Monne <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
Reviewed-by: Boris Ostrovsky <[email protected]>
On Wed, Aug 09, 2017 at 03:31:40PM -0700, Munehisa Kamata wrote:
> Since commit d05d7f40791c ("Merge branch 'for-4.8/core' of
> git://git.kernel.dk/linux-block") and 3fc9d690936f ("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: d05d7f40791c ("Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block")
> Fixes: 3fc9d690936f ("Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block")
> Signed-off-by: Munehisa Kamata <[email protected]>
> Reviewed-by: Thomas Friebel <[email protected]>
> Reviewed-by: Eduardo Valentin <[email protected]>
> Cc: Boris Ostrovsky <[email protected]>
> Cc: Juergen Gross <[email protected]>
> Cc: Konrad Rzeszutek Wilk <[email protected]>
> Cc: Roger Pau Monne <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
Reviewed-by: Roger Pau Monn? <[email protected]>
Thanks, Roger.