diff options
| author | Ye Bin <yebin10@huawei.com> | 2022-11-07 11:39:56 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-11-24 06:58:11 -0700 |
| commit | 90b0296ece4bd8f70419f0addc1171be6feee195 (patch) | |
| tree | fa5ba562c424a74450a9e220f2c9f22575e9e840 /block | |
| parent | 8692814b77ca4228a99da8a005de0acf40af6132 (diff) | |
block: fix crash in 'blk_mq_elv_switch_none'
Syzbot found the following issue:
general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]
CPU: 0 PID: 5234 Comm: syz-executor931 Not tainted 6.1.0-rc3-next-20221102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:__elevator_get block/elevator.h:94 [inline]
RIP: 0010:blk_mq_elv_switch_none block/blk-mq.c:4593 [inline]
RIP: 0010:__blk_mq_update_nr_hw_queues block/blk-mq.c:4658 [inline]
RIP: 0010:blk_mq_update_nr_hw_queues+0x304/0xe40 block/blk-mq.c:4709
RSP: 0018:ffffc90003cdfc08 EFLAGS: 00010206
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 000000000000001d RSI: 0000000000000002 RDI: 00000000000000e8
RBP: ffff88801dbd0000 R08: ffff888027c89398 R09: ffffffff8de2e517
R10: fffffbfff1bc5ca2 R11: 0000000000000000 R12: ffffc90003cdfc70
R13: ffff88801dbd0008 R14: ffff88801dbd03f8 R15: ffff888027c89380
FS: 0000555557259300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005d84c8 CR3: 000000007a7cb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nbd_start_device+0x153/0xc30 drivers/block/nbd.c:1355
nbd_start_device_ioctl drivers/block/nbd.c:1405 [inline]
__nbd_ioctl drivers/block/nbd.c:1481 [inline]
nbd_ioctl+0x5a1/0xbd0 drivers/block/nbd.c:1521
blkdev_ioctl+0x36e/0x800 block/ioctl.c:614
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
As after dd6f7f17bf58 commit move '__elevator_get(qe->type)' before set
'qe->type', so will lead to access wild pointer.
To solve above issue get 'qe->type' after set 'qe->type'.
Reported-by: syzbot+746a4eece09f86bc39d7@syzkaller.appspotmail.com
Fixes:dd6f7f17bf58("block: add proper helpers for elevator_type module refcount management")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221107033956.3276891-1-yebin@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index cdd8efcec191..4e6b3ccd4989 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4630,9 +4630,9 @@ static bool blk_mq_elv_switch_none(struct list_head *head, INIT_LIST_HEAD(&qe->node); qe->q = q; + qe->type = q->elevator->type; /* keep a reference to the elevator module as we'll switch back */ __elevator_get(qe->type); - qe->type = q->elevator->type; list_add(&qe->node, head); elevator_disable(q); mutex_unlock(&q->sysfs_lock); |