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authorxiao jin <jin.xiao@intel.com>2018-07-30 14:11:12 +0800
committerJens Axboe <axboe@kernel.dk>2018-07-30 08:28:39 -0600
commit54648cf1ec2d7f4b6a71767799c45676a138ca24 (patch)
tree0af9e04a43e25fa1e7206bc30bded1287803c850 /block
parentf7f1fc363aab4601786d373569c1ae802ea593d0 (diff)
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block: blk_init_allocated_queue() set q->fq as NULL in the fail case
We find the memory use-after-free issue in __blk_drain_queue() on the kernel 4.14. After read the latest kernel 4.18-rc6 we think it has the same problem. Memory is allocated for q->fq in the blk_init_allocated_queue(). If the elevator init function called with error return, it will run into the fail case to free the q->fq. Then the __blk_drain_queue() uses the same memory after the free of the q->fq, it will lead to the unpredictable event. The patch is to set q->fq as NULL in the fail case of blk_init_allocated_queue(). Fixes: commit 7c94e1c157a2 ("block: introduce blk_flush_queue to drive flush machinery") Cc: <stable@vger.kernel.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: xiao jin <jin.xiao@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 03a4ea93a5f3..23cd1b7770e7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1184,6 +1184,7 @@ out_exit_flush_rq:
q->exit_rq_fn(q, q->fq->flush_rq);
out_free_flush_queue:
blk_free_flush_queue(q->fq);
+ q->fq = NULL;
return -ENOMEM;
}
EXPORT_SYMBOL(blk_init_allocated_queue);