Make sure log record don't stray beyond valid memory region.
There is a lack of verification of the space occupied by fixed members
of lr_t in the zil_parse.
We can create a crafted image to trigger an out of bounds read by
following these steps:
1) Do some file operations and reboot to simulate abnormal exit
without umount
2) zil_chain.zc_nused: 0x1000
3) First lr_t
lr_t.lrc_txtype: 0x0
lr_t.lrc_reclen: 0x1000-0xb8-0x1
lr_t.lrc_txg: 0x0
lr_t.lrc_seq: 0x1
4) Update checksum in zil_chain.zc_eck
Fix:
Add some checks to make sure the remaining bytes are large enough to
hold an log record.
Signed-off-by: XDTG <click1799@163.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
ac6500389b