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author | Ming Lei <ming.lei@canonical.com> | 2015-08-09 03:41:50 -0400 |
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committer | Luis Henriques <luis.henriques@canonical.com> | 2015-09-28 10:21:41 +0100 |
commit | 3cb19874fbe77035840e9c22f433ea5c41507018 (patch) | |
tree | ceaea4df7b2861b2c590d2387c7bea1d20928298 /arch | |
parent | 05e638ae310a451dbb5be0dfbf352bbfd88464fb (diff) | |
download | linux-stable-3cb19874fbe77035840e9c22f433ea5c41507018.tar.gz linux-stable-3cb19874fbe77035840e9c22f433ea5c41507018.tar.bz2 linux-stable-3cb19874fbe77035840e9c22f433ea5c41507018.zip |
blk-mq: fix buffer overflow when reading sysfs file of 'pending'
commit 596f5aad2a704b72934e5abec1b1b4114c16f45b upstream.
There may be lots of pending requests so that the buffer of PAGE_SIZE
can't hold them at all.
One typical example is scsi-mq, the queue depth(.can_queue) of
scsi_host and blk-mq is quite big but scsi_device's queue_depth
is a bit small(.cmd_per_lun), then it is quite easy to have lots
of pending requests in hw queue.
This patch fixes the following warning and the related memory
destruction.
[ 359.025101] fill_read_buffer: blk_mq_hw_sysfs_show+0x0/0x7d returned bad count^M
[ 359.055595] irq event stamp: 15537^M
[ 359.055606] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC ^M
[ 359.055614] Dumping ftrace buffer:^M
[ 359.055660] (ftrace buffer empty)^M
[ 359.055672] Modules linked in: nbd ipv6 kvm_intel kvm serio_raw^M
[ 359.055678] CPU: 4 PID: 21631 Comm: stress-ng-sysfs Not tainted 4.2.0-rc5-next-20150805 #434^M
[ 359.055679] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011^M
[ 359.055682] task: ffff8802161cc000 ti: ffff88021b4a8000 task.ti: ffff88021b4a8000^M
[ 359.055693] RIP: 0010:[<ffffffff811541c5>] [<ffffffff811541c5>] __kmalloc+0xe8/0x152^M
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions