Gitweb:     http://git.kernel.org/linus/3228149ceb8b045e324cd268be9182bb26e6488b
Commit:     3228149ceb8b045e324cd268be9182bb26e6488b
Parent:     ed7b44af3517441ba46b84da13773d24809ffdd3
Author:     Dave Chinner <david@fromorbit.com>
AuthorDate: Thu Jan 22 15:37:47 2009 +1100
Committer:  Felix Blyakher <felixb@sgi.com>
CommitDate: Tue Feb 3 10:19:33 2009 -0600

    xfs: Check buffer lengths in log recovery
    
    Before trying to obtain, read or write a buffer,
    check that the buffer length is actually valid. If
    it is not valid, then something read in the recovery
    process has been corrupted and we should abort
    recovery.
    
    Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
    Tested-by: Eric Sesterhenn <snakebyte@gmx.de>
    Reviewed-by: Christoph Hellwig <hch@infradead.org>
    Reviewed-by: Felix Blyakher <felixb@sgi.com>
    Signed-off-by: Dave Chinner <david@fromorbit.com>
    Signed-off-by: Felix Blyakher <felixb@sgi.com>
---
 fs/xfs/xfs_log_recover.c |   31 +++++++++++++++++++++++++------
 1 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 35cca98..b1047de 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -70,16 +70,21 @@ STATIC void	xlog_recover_check_summary(xlog_t *);
 xfs_buf_t *
 xlog_get_bp(
 	xlog_t		*log,
-	int		num_bblks)
+	int		nbblks)
 {
-	ASSERT(num_bblks > 0);
+	if (nbblks <= 0 || nbblks > log->l_logBBsize) {
+		xlog_warn("XFS: Invalid block length (0x%x) given for buffer", nbblks);
+		XFS_ERROR_REPORT("xlog_get_bp(1)",
+				 XFS_ERRLEVEL_HIGH, log->l_mp);
+		return NULL;
+	}
 
 	if (log->l_sectbb_log) {
-		if (num_bblks > 1)
-			num_bblks += XLOG_SECTOR_ROUNDUP_BBCOUNT(log, 1);
-		num_bblks = XLOG_SECTOR_ROUNDUP_BBCOUNT(log, num_bblks);
+		if (nbblks > 1)
+			nbblks += XLOG_SECTOR_ROUNDUP_BBCOUNT(log, 1);
+		nbblks = XLOG_SECTOR_ROUNDUP_BBCOUNT(log, nbblks);
 	}
-	return xfs_buf_get_noaddr(BBTOB(num_bblks), log->l_mp->m_logdev_targp);
+	return xfs_buf_get_noaddr(BBTOB(nbblks), log->l_mp->m_logdev_targp);
 }
 
 void
@@ -102,6 +107,13 @@ xlog_bread(
 {
 	int		error;
 
+	if (nbblks <= 0 || nbblks > log->l_logBBsize) {
+		xlog_warn("XFS: Invalid block length (0x%x) given for buffer", nbblks);
+		XFS_ERROR_REPORT("xlog_bread(1)",
+				 XFS_ERRLEVEL_HIGH, log->l_mp);
+		return EFSCORRUPTED;
+	}
+
 	if (log->l_sectbb_log) {
 		blk_no = XLOG_SECTOR_ROUNDDOWN_BLKNO(log, blk_no);
 		nbblks = XLOG_SECTOR_ROUNDUP_BBCOUNT(log, nbblks);
@@ -139,6 +151,13 @@ xlog_bwrite(
 {
 	int		error;
 
+	if (nbblks <= 0 || nbblks > log->l_logBBsize) {
+		xlog_warn("XFS: Invalid block length (0x%x) given for buffer", nbblks);
+		XFS_ERROR_REPORT("xlog_bwrite(1)",
+				 XFS_ERRLEVEL_HIGH, log->l_mp);
+		return EFSCORRUPTED;
+	}
+
 	if (log->l_sectbb_log) {
 		blk_no = XLOG_SECTOR_ROUNDDOWN_BLKNO(log, blk_no);
 		nbblks = XLOG_SECTOR_ROUNDUP_BBCOUNT(log, nbblks);
--
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