| Message ID | 20200220024441.11558-8-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Eight patches related to changing the number of hardware queues | expand |
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 9846648780b6..ba83fd0537ce 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -1469,7 +1469,12 @@ static const struct blk_mq_ops null_mq_ops = { static void null_del_dev(struct nullb *nullb) { - struct nullb_device *dev = nullb->dev; + struct nullb_device *dev; + + if (!nullb) + return; + + dev = nullb->dev; ida_simple_remove(&nullb_indexes, nullb->index);
If null_add_dev() fails then null_del_dev() is called with a NULL argument. Make null_del_dev() handle this scenario correctly. This patch fixes the following KASAN complaint: null-ptr-deref in null_del_dev+0x28/0x280 [null_blk] Read of size 8 at addr 0000000000000000 by task find/1062 Call Trace: dump_stack+0xa5/0xe6 __kasan_report.cold+0x65/0x99 kasan_report+0x16/0x20 __asan_load8+0x58/0x90 null_del_dev+0x28/0x280 [null_blk] nullb_group_drop_item+0x7e/0xa0 [null_blk] client_drop_item+0x53/0x80 [configfs] configfs_rmdir+0x395/0x4e0 [configfs] vfs_rmdir+0xb6/0x220 do_rmdir+0x238/0x2c0 __x64_sys_unlinkat+0x75/0x90 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jth@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/block/null_blk_main.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)