[PATCH 1/4] befs: check allocation_group number before use

[Salah Triki]

Check that the allocation group number is not greater or equal to the
number of allocations group in the file system and return BEF_ERR in the
case of error.

Signed-off-by: Salah Triki <salah.triki@xxxxxxxxx>
---
 fs/befs/befs.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/befs/befs.h b/fs/befs/befs.h
index 55f3ea2..6daf4c4 100644
--- a/fs/befs/befs.h
+++ b/fs/befs/befs.h
@@ -121,6 +121,11 @@ BEFS_I(const struct inode *inode)
 static inline befs_blocknr_t
 iaddr2blockno(struct super_block *sb, const befs_inode_addr *iaddr)
 {
+	if (iaddr->allocation_group >= BEFS_SB(sb)->num_ags) {
+		befs_error(sb, "BEFS: Invalid allocation group %u, max is %u",
+			   iaddr->allocation_group, BEFS_SB(sb)->num_ags);
+		return BEFS_ERR;
+	}
 	return ((iaddr->allocation_group << BEFS_SB(sb)->ag_shift) +
 		iaddr->start);
 }
-- 
1.9.1