[ Upstream commit e49be14b8d80e23bb7c53d78c21717a474ade76b ]
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: a2de733c78fa ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/scrub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index a08a4d6f540f9..916c397704679 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -592,6 +592,7 @@ 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;
@@ -616,7 +617,6 @@ 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);