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author | Ming Lei <ming.lei@redhat.com> | 2018-11-02 08:50:51 +0800 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2018-11-01 19:59:51 -0600 |
commit | 153fcd5f6d93b8e1e4040b1337f564a10f8d93af (patch) | |
tree | 078885a1ddf2ed0cf8e3b8b47a253916f950cc92 /drivers | |
parent | c57cdf7a9e51d97a43e29b8f4a04157875104000 (diff) | |
download | linux-stable-153fcd5f6d93b8e1e4040b1337f564a10f8d93af.tar.gz linux-stable-153fcd5f6d93b8e1e4040b1337f564a10f8d93af.tar.bz2 linux-stable-153fcd5f6d93b8e1e4040b1337f564a10f8d93af.zip |
block: brd: associate with queue until adding disk
brd_free() may be called in failure path on one brd instance which
disk isn't added yet, so release handler of gendisk may free the
associated request_queue early and causes the following use-after-free[1].
This patch fixes this issue by associating gendisk with request_queue
just before adding disk.
[1] KASAN: use-after-free Read in del_timer_syncNon-volatile memory driver v1.3
Linux agpgart interface v0.103
[drm] Initialized vgem 1.0.0 20120112 for virtual device on minor 0
usbcore: registered new interface driver udl
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20
kernel/locking/lockdep.c:3218
Read of size 8 at addr ffff8801d1b6b540 by task swapper/0/1
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x244/0x39d lib/dump_stack.c:113
print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
__lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218
lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
del_timer_sync+0xb7/0x270 kernel/time/timer.c:1283
blk_cleanup_queue+0x413/0x710 block/blk-core.c:809
brd_free+0x5d/0x71 drivers/block/brd.c:422
brd_init+0x2eb/0x393 drivers/block/brd.c:518
do_one_initcall+0x145/0x957 init/main.c:890
do_initcall_level init/main.c:958 [inline]
do_initcalls init/main.c:966 [inline]
do_basic_setup init/main.c:984 [inline]
kernel_init_freeable+0x5c6/0x6b9 init/main.c:1148
kernel_init+0x11/0x1ae init/main.c:1068
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350
Reported-by: syzbot+3701447012fe951dabb2@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/block/brd.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/block/brd.c b/drivers/block/brd.c index df8103dd40ac..c18586fccb6f 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -396,15 +396,14 @@ static struct brd_device *brd_alloc(int i) disk->first_minor = i * max_part; disk->fops = &brd_fops; disk->private_data = brd; - disk->queue = brd->brd_queue; disk->flags = GENHD_FL_EXT_DEVT; sprintf(disk->disk_name, "ram%d", i); set_capacity(disk, rd_size * 2); - disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; + brd->brd_queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; /* Tell the block layer that this is not a rotational device */ - blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); - blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); + blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue); + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, brd->brd_queue); return brd; @@ -436,6 +435,7 @@ static struct brd_device *brd_init_one(int i, bool *new) brd = brd_alloc(i); if (brd) { + brd->brd_disk->queue = brd->brd_queue; add_disk(brd->brd_disk); list_add_tail(&brd->brd_list, &brd_devices); } @@ -503,8 +503,14 @@ static int __init brd_init(void) /* point of no return */ - list_for_each_entry(brd, &brd_devices, brd_list) + list_for_each_entry(brd, &brd_devices, brd_list) { + /* + * associate with queue just before adding disk for + * avoiding to mess up failure path + */ + brd->brd_disk->queue = brd->brd_queue; add_disk(brd->brd_disk); + } blk_register_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS, THIS_MODULE, brd_probe, NULL, NULL); |