Description: btrfs: crafted image causes null deref in btrfs_verify_dev_extent
References:
 https://github.com/bobfuzzer/CVE-2019-18885
Notes:
 bwh> If this issue is strictly limited to btrfs_verify_dev_extent()
 bwh> then it was introduced at the earliest by the introduction of that
 bwh> function in 4.19 (commit cf90d884b347).  There may be similar
 bwh> issues elsewhere though.
Bugs:
upstream: released (5.1-rc1) [09ba3bc9dd150457c506e4661380a6183af651c1]
4.19-upstream-stable: released (4.19.129) [8cb9b069fa631b613bbbd6f63887190e55cafa3c]
4.9-upstream-stable: N/A "Vulnerable code not present"
3.16-upstream-stable: N/A "Vulnerable code not present"
sid: released (5.2.6-1)
4.19-buster-security: released (4.19.131-1)
4.9-stretch-security: N/A "Vulnerable code not present"
3.16-jessie-security: N/A "Vulnerable code not present"