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| author |   Weiping Zhang <zhangweiping@didiglobal.com> | 2020-05-13 08:44:05 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2020-05-12 20:20:22 -0600 |
| commit | aa880ad690ab6d4c53934af85fb5a43e69ecb0f5 (patch) | |
| tree | 63839703b328dac699234f1fe5b2fb5fc977dd15 /block/genhd.c | |
| parent | bdi: fix up for "remove the name field in struct backing_dev_info" (diff) | |
| download | linux-dev-aa880ad690ab6d4c53934af85fb5a43e69ecb0f5.tar.xz linux-dev-aa880ad690ab6d4c53934af85fb5a43e69ecb0f5.zip | |
block: reset mapping if failed to update hardware queue count
When we increase hardware queue count, blk_mq_update_queue_map will
reset the mapping between cpu and hardware queue base on the hardware
queue count(set->nr_hw_queues). The mapping cannot be reset if it
encounters error in blk_mq_realloc_hw_ctxs, but the fallback flow will
continue using it, then blk_mq_map_swqueue will touch a invalid memory,
because the mapping points to a wrong hctx.
blktest block/030:
null_blk: module loaded
Increasing nr_hw_queues to 8 fails, fallback to 1
==================================================================
BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x2f2/0x830
Read of size 8 at addr 0000000000000128 by task nproc/8541
CPU: 5 PID: 8541 Comm: nproc Not tainted 5.7.0-rc4-dbg+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
Call Trace:
dump_stack+0xa5/0xe6
__kasan_report.cold+0x65/0xbb
kasan_report+0x45/0x60
check_memory_region+0x15e/0x1c0
__kasan_check_read+0x15/0x20
blk_mq_map_swqueue+0x2f2/0x830
__blk_mq_update_nr_hw_queues+0x3df/0x690
blk_mq_update_nr_hw_queues+0x32/0x50
nullb_device_submit_queues_store+0xde/0x160 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x14b/0x2d0
ksys_write+0xdd/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x310
entry_SYSCALL_64_after_hwframe+0x49/0xb3
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Tested-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/genhd.c')
0 files changed, 0 insertions, 0 deletions