btrfs_root_node in fs/btrfs/ctree.c in the Linux kernel through 5.3.12 allows a NULL pointer dereference because rcu_dereference(root->node) can be zero.
5.13.0-19.193.11.0-12.193.12.0-1.33.12.0-2.53.12.0-2.73.12.0-3.83.12.0-3.93.12.0-4.103.12.0-4.123.12.0-5.133.12.0-7.15+170 more4.13.0-16.194.13.0-17.204.13.0-25.294.13.0-32.354.15.0-10.114.15.0-101.1024.15.0-106.1074.15.0-108.1094.15.0-12.134.15.0-13.14+41 more4.15.0-109.1105.3.0-18.195.3.0-24.265.4.0-9.126.11.0-8.86.5.0-9.94.2.0-16.194.2.0-17.214.2.0-19.234.3.0-1.104.3.0-2.114.3.0-5.164.3.0-6.174.3.0-7.184.4.0-10.254.4.0-101.124+167 more5.13.0-1005.66.11.0-1004.44.4.0-1001.104.4.0-1003.124.4.0-1004.134.4.0-1007.164.4.0-1009.184.4.0-1011.204.4.0-1012.214.4.0-1013.224.4.0-1016.254.4.0-1017.26+123 moreExploitability
AV:LAC:LPR:NUI:RScope
S:UImpact
C:NI:NA:HCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H