diff options
author | c1ick <[email protected]> | 2024-08-01 08:17:04 +0800 |
---|---|---|
committer | Tony Hutter <[email protected]> | 2024-08-22 15:12:54 -0700 |
commit | ac6500389b12da35c954e81d6317944338cce9dc (patch) | |
tree | 587c6bda69312f48dd4b15c374f1a3581e41a752 /module/zfs/zil.c | |
parent | 1f055436f3a2d64823ca45636d409a8715d871a3 (diff) |
zfs: add bounds checking to zil_parse (#16308)
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 <[email protected]>
Reviewed-by: Alexander Motin <[email protected]>
Reviewed-by: Tony Hutter <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Diffstat (limited to 'module/zfs/zil.c')
-rw-r--r-- | module/zfs/zil.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/module/zfs/zil.c b/module/zfs/zil.c index 9b5d866a8..9293429e4 100644 --- a/module/zfs/zil.c +++ b/module/zfs/zil.c @@ -513,9 +513,26 @@ zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, for (; lrp < end; lrp += reclen) { lr_t *lr = (lr_t *)lrp; + + /* + * Are the remaining bytes large enough to hold an + * log record? + */ + if ((char *)(lr + 1) > end) { + cmn_err(CE_WARN, "zil_parse: lr_t overrun"); + error = SET_ERROR(ECKSUM); + arc_buf_destroy(abuf, &abuf); + goto done; + } reclen = lr->lrc_reclen; - ASSERT3U(reclen, >=, sizeof (lr_t)); - ASSERT3U(reclen, <=, end - lrp); + if (reclen < sizeof (lr_t) || reclen > end - lrp) { + cmn_err(CE_WARN, + "zil_parse: lr_t has an invalid reclen"); + error = SET_ERROR(ECKSUM); + arc_buf_destroy(abuf, &abuf); + goto done; + } + if (lr->lrc_seq > claim_lr_seq) { arc_buf_destroy(abuf, &abuf); goto done; |