xfs: prevent kernel crash due to corrupted inode log format
Andras Korn reported an oops on log replay causes by a corrupted
xfs_inode_log_format_t passing a 0 size to kmem_zalloc. This patch handles
to small or too large numbers of log regions gracefully by rejecting the
log replay with a useful error message.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Andras Korn <korn-sgi.com@chardonnay.math.bme.hu>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 504d540..ceeba45 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1455,10 +1455,19 @@
item = item->ri_prev;
if (item->ri_total == 0) { /* first region to be added */
- item->ri_total = in_f->ilf_size;
- ASSERT(item->ri_total <= XLOG_MAX_REGIONS_IN_ITEM);
- item->ri_buf = kmem_zalloc((item->ri_total *
- sizeof(xfs_log_iovec_t)), KM_SLEEP);
+ if (in_f->ilf_size == 0 ||
+ in_f->ilf_size > XLOG_MAX_REGIONS_IN_ITEM) {
+ xlog_warn(
+ "XFS: bad number of regions (%d) in inode log format",
+ in_f->ilf_size);
+ ASSERT(0);
+ return XFS_ERROR(EIO);
+ }
+
+ item->ri_total = in_f->ilf_size;
+ item->ri_buf =
+ kmem_zalloc(item->ri_total * sizeof(xfs_log_iovec_t),
+ KM_SLEEP);
}
ASSERT(item->ri_total > item->ri_cnt);
/* Description region is ri_buf[0] */