Commit e49be14b authored Feb 19, 2019 by Dan Robertson Committed by David Sterba Feb 25, 2019

btrfs: init csum_list before possible free



The scrub_ctx csum_list member must be initialized before scrub_free_ctx
is called. If the csum_list is not initialized beforehand, the
list_empty call in scrub_free_csums will result in a null deref if the
allocation fails in the for loop.

Fixes: a2de733c ("btrfs: scrub")
CC: stable@vger.kernel.org # 3.0+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 57a50e25

fs/btrfs/scrub.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -584,6 +584,7 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
		sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
		sctx->curr = -1;
		sctx->fs_info = fs_info;
		INIT_LIST_HEAD(&sctx->csum_list);
		for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
		struct scrub_bio *sbio;

		@@ -608,7 +609,6 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
		atomic_set(&sctx->workers_pending, 0);
		atomic_set(&sctx->cancel_req, 0);
		sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
		INIT_LIST_HEAD(&sctx->csum_list);

		spin_lock_init(&sctx->list_lock);
		spin_lock_init(&sctx->stat_lock);

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