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authorBart Van Assche <bvanassche@acm.org>2020-03-09 21:26:21 -0700
committerJens Axboe <axboe@kernel.dk>2020-03-10 07:09:59 -0600
commit2004bfdef945fe55196db6b9cdf321fbc75bb0de (patch)
tree4073b819a82c7830c9991893e767861afee5673d /drivers/block
parent78b10be23d42e66fc42e52b9ae620f0a6ef5b8c7 (diff)
null_blk: Fix the null_add_dev() error path
If null_add_dev() fails, clear dev->nullb. This patch fixes the following KASAN complaint: BUG: KASAN: use-after-free in nullb_device_submit_queues_store+0xcf/0x160 [null_blk] Read of size 8 at addr ffff88803280fc30 by task check/8409 Call Trace: dump_stack+0xa5/0xe6 print_address_description.constprop.0+0x26/0x260 __kasan_report.cold+0x7b/0x99 kasan_report+0x16/0x20 __asan_load8+0x58/0x90 nullb_device_submit_queues_store+0xcf/0x160 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x145/0x2c0 ksys_write+0xd7/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff370926317 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007fff2dd2da48 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007ff370926317 RDX: 0000000000000002 RSI: 0000559437ef23f0 RDI: 0000000000000001 RBP: 0000559437ef23f0 R08: 000000000000000a R09: 0000000000000001 R10: 0000559436703471 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ff370a006a0 R14: 00007ff370a014a0 R15: 00007ff370a008a0 Allocated by task 8409: save_stack+0x23/0x90 __kasan_kmalloc.constprop.0+0xcf/0xe0 kasan_kmalloc+0xd/0x10 kmem_cache_alloc_node_trace+0x129/0x4c0 null_add_dev+0x24a/0xe90 [null_blk] nullb_device_power_store+0x1b6/0x270 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x145/0x2c0 ksys_write+0xd7/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8409: save_stack+0x23/0x90 __kasan_slab_free+0x112/0x160 kasan_slab_free+0x12/0x20 kfree+0xdf/0x250 null_add_dev+0xaf3/0xe90 [null_blk] nullb_device_power_store+0x1b6/0x270 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x145/0x2c0 ksys_write+0xd7/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 2984c8684f96 ("nullb: factor disk parameters") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/null_blk_main.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 83e31b81db3c..80d3dcb8722c 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -1817,6 +1817,7 @@ out_cleanup_queues:
cleanup_queues(nullb);
out_free_nullb:
kfree(nullb);
+ dev->nullb = NULL;
out:
return rv;
}